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Background: The 2022-2023 United States influenza season had unusually early influenza activity with high hospitalization rates. Vaccine-matched A(H3N2) viruses predominated, with lower levels of A(H1N1)pdm09 activity also observed., Methods: Using the test-negative design, we evaluated influenza vaccine effectiveness (VE) during the 2022-2023 season against influenza A-associated emergency department/urgent care (ED/UC) visits and hospitalizations from October 2022 to March 2023 among adults (aged ≥18 years) with acute respiratory illness (ARI). VE was estimated by comparing odds of seasonal influenza vaccination among case-patients (influenza A test positive by molecular assay) and controls (influenza test negative), applying inverse-propensity-to-be-vaccinated weights., Results: The analysis included 85 389 ED/UC ARI encounters (17.0% influenza A positive; 37.8% vaccinated overall) and 19 751 hospitalizations (9.5% influenza A positive; 52.8% vaccinated overall). VE against influenza A-associated ED/UC encounters was 44% (95% confidence interval [CI], 40%-47%) overall and 45% and 41% among adults aged 18-64 and ≥65 years, respectively. VE against influenza A-associated hospitalizations was 35% (95% CI, 27%-43%) overall and 23% and 41% among adults aged 18-64 and ≥65 years, respectively., Conclusions: VE was moderate during the 2022-2023 influenza season, a season characterized with increased burden of influenza and co-circulation with other respiratory viruses. Vaccination is likely to substantially reduce morbidity, mortality, and strain on healthcare resources., Competing Interests: Potential conflicts of interest. During the conduct of the study, all Westat- and Kaiser Permanente Northern California Division of Research–affiliated authors reported receiving contractual support from the CDC via payments made to their respective institutions. Additionally, all authors affiliated with Baylor Scott & White Health, Children's Minnesota, Columbia University Irving Medical Center, HealthPartners Institute, Intermountain Healthcare, Kaiser Permanente Center for Health Research, Regenstrief Institute, University of Colorado Anschutz Medical Campus, and Vanderbilt University Medical Center reported receiving contractual support from the CDC during the conduct of the study, via subcontracts from Westat, Inc, with payments made to their respective institutions. Unrelated to the submitted work, the following disclosures were reported from the past 36 months: A. L. N. received grants from Pfizer and Vir Biotechnology; M. N. received grants directly from CDC and from CDC via subcontracts from Abt Associates and Vanderbilt University Medical Center to her institution; C. E. M. received grants AstraZeneca; S. R. received grants from GSK; and N. P. K. received research support from Pfizer, Merck, GlaxoSmithKline, Sanofi Pasteur, and Seqirus. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2023.)

In September 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (monovalent XBB.1.5) COVID-19 vaccination for all persons aged ≥6 months to prevent COVID-19, including severe disease. As with past COVID-19 vaccines, additional doses may be considered for persons with immunocompromising conditions, who are at higher risk for severe COVID-19 and might have decreased response to vaccination. In this analysis, vaccine effectiveness (VE) of an updated COVID-19 vaccine dose against COVID-19-associated hospitalization was evaluated during September 2023-February 2024 using data from the VISION VE network. Among adults aged ≥18 years with immunocompromising conditions, VE against COVID-19-associated hospitalization was 38% in the 7-59 days after receipt of an updated vaccine dose and 34% in the 60-119 days after receipt of an updated dose. Few persons (18%) in this high-risk study population had received updated COVID-19 vaccine. All persons aged ≥6 months should receive updated 2023-2024 COVID-19 vaccination; persons with immunocompromising conditions may get additional updated COVID-19 vaccine doses ≥2 months after the last recommended COVID-19 vaccine., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Brian E. Dixon reports institutional support from the National Institutes of Health (NIH) and the U.S. Department of Veterans Affairs and royalties from Elsevier, Inc. for a book on health information technology and from Springer Nature for a book on health information technology. Nicola P. Klein reports institutional support from Sanofi Pasteur, Merck, Pfizer, Seqiris, and GSK; uncompensated membership on an expert panel for a planned Hepatitis E Phase II vaccine clinical trial among pregnant women in Pakistan, sponsored by the International Vaccine Institute; unpaid membership on the Western States COVID-19 Scientific Safety Review Workgroup, the Board on Population Health and Public Health Practice, the National Academies of Science, Engineering and Medicine, and the National Vaccine Advisory Committee Safety Subcommittee. Charlene E. McEvoy reports grants or contracts from NIH, the Department of Defense, Patient-Centered Outcomes Research Institute, Astra Zeneca, and GSK; payment or honorarium from Pri-Med for a lecture on incorporation of ACT and CAT into electronic health records to improve outcomes in patients with asthma and chronic obstructive pulmonary disease; and uncompensated participation on the American Lung Association of Minnesota Board, the Minnesota Department of Health Long COVID Advisory Committee, and the Minnesota Department of Health Asthma Care Advisory Committee. Tamara Sheffield reports uncompensated membership on CDC’s Advisory Committee on Immunization Practices Influenza Vaccine Work Group, chairmanship of the Utah Adult Immunization Coalition vaccine quality improvement and advocacy group, and membership on the Utah Department of Health and Human Services Scientific Advisory Committee on Vaccines. Ousseny Zerbo reports a grant from the National Institute of Allergy and Infectious Diseases. Suchitra Rao reports grants from Biofire and GSK. No other potential conflicts of interest were disclosed.

Background: During the 2022-2023 influenza season, the United States experienced the highest influenza-associated pediatric hospitalization rate since 2010-2011. Influenza A/H3N2 infections were predominant., Methods: We analyzed acute respiratory illness (ARI)-associated emergency department or urgent care (ED/UC) encounters or hospitalizations at 3 health systems among children and adolescents aged 6 months-17 years who had influenza molecular testing during October 2022-March 2023. We estimated influenza A vaccine effectiveness (VE) using a test-negative approach. The odds of vaccination among influenza-A-positive cases and influenza-negative controls were compared after adjusting for confounders and applying inverse-propensity-to-be-vaccinated weights. We developed overall and age-stratified VE models., Results: Overall, 13 547 of 44 787 (30.2%) eligible ED/UC encounters and 263 of 1862 (14.1%) hospitalizations were influenza-A-positive cases. Among ED/UC patients, 15.2% of influenza-positive versus 27.1% of influenza-negative patients were vaccinated; VE was 48% (95% confidence interval [CI], 44-52%) overall, 53% (95% CI, 47-58%) among children aged 6 months-4 years, and 38% (95% CI, 30-45%) among those aged 9-17 years. Among hospitalizations, 17.5% of influenza-positive versus 33.4% of influenza-negative patients were vaccinated; VE was 40% (95% CI, 6-61%) overall, 56% (95% CI, 23-75%) among children ages 6 months-4 years, and 46% (95% CI, 2-70%) among those 5-17 years., Conclusions: During the 2022-2023 influenza season, vaccination reduced the risk of influenza-associated ED/UC encounters and hospitalizations by almost half (overall VE, 40-48%). Influenza vaccination is a critical tool to prevent moderate-to-severe influenza illness in children and adolescents., Competing Interests: Potential conflicts of interest . N. P. K. reports research support from Sanofi Pasteur and Seqirus for unrelated adult influenza vaccine effectiveness studies, and from Pfizer, Merck, and GlaxoSmithKline for unrelated studies. S. R. received funds from GlaxoSmithKline. M. G. reports a research grant and contract for the CDC Ambulatory US Flu/COVID VE Network, a grant for HAIVEN Adult Inpatient Flu/COVID VE, a contract for SYNERGY FLU/COVID study, and subcontracts for the IVY COVID/FLU VE PHS project and RECOVER-PROTECT COVID Cohort studies. D.-H. Y., L. K., M. M. D., S. W. B., and Z. A. W. report payments made to Westat via CDC contract number 200-2019-F-06819. A. B. K., A. L. N., J. A., K. D., K. N., M. B. D., M. G., N. G., P. J. E., S. A. I, S. J. G., S. R., and T. C. O. report payments made to their institution by CDC via Westat. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2023.)

Background: Although psychiatric disorders have been associated with reduced immune responses to other vaccines, it remains unknown whether they influence COVID-19 vaccine effectiveness (VE). This study evaluated risk of COVID-19 hospitalization and estimated mRNA VE stratified by psychiatric disorder status., Methods: In a retrospective cohort analysis of the VISION Network in four US states, the rate of laboratory-confirmed COVID-19-associated hospitalization between December 2021 and August 2022 was compared across psychiatric diagnoses and by monovalent mRNA COVID-19 vaccination status using Cox proportional hazards regression., Results: Among 2,436,999 adults, 22.1% had ≥1 psychiatric disorder. The incidence of COVID-19-associated hospitalization was higher among patients with any versus no psychiatric disorder (394 vs. 156 per 100,000 person-years, p < 0.001). Any psychiatric disorder (adjusted hazard ratio [aHR], 1.27; 95% CI, 1.18-1.37) and mood (aHR, 1.25; 95% CI, 1.15-1.36), anxiety (aHR, 1.33, 95% CI, 1.22-1.45), and psychotic (aHR, 1.41; 95% CI, 1.14-1.74) disorders were each significant independent predictors of hospitalization. Among patients with any psychiatric disorder, aHRs for the association between vaccination and hospitalization were 0.35 (95% CI, 0.25-0.49) after a recent second dose, 0.08 (95% CI, 0.06-0.11) after a recent third dose, and 0.33 (95% CI, 0.17-0.66) after a recent fourth dose, compared to unvaccinated patients. Corresponding VE estimates were 65%, 92%, and 67%, respectively, and were similar among patients with no psychiatric disorder (68%, 92%, and 79%)., Conclusion: Psychiatric disorders were associated with increased risk of COVID-19-associated hospitalization. However, mRNA vaccination provided similar protection regardless of psychiatric disorder status, highlighting its benefit for individuals with psychiatric disorders., (© 2024 The Authors. Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.)

In September 2023, CDC's Advisory Committee on Immunization Practices recommended updated 2023-2024 (monovalent XBB.1.5) COVID-19 vaccination for all persons aged ≥6 months to prevent COVID-19, including severe disease. However, few estimates of updated vaccine effectiveness (VE) against medically attended illness are available. This analysis evaluated VE of an updated COVID-19 vaccine dose against COVID-19-associated emergency department (ED) or urgent care (UC) encounters and hospitalization among immunocompetent adults aged ≥18 years during September 2023-January 2024 using a test-negative, case-control design with data from two CDC VE networks. VE against COVID-19-associated ED/UC encounters was 51% (95% CI = 47%-54%) during the first 7-59 days after an updated dose and 39% (95% CI = 33%-45%) during the 60-119 days after an updated dose. VE estimates against COVID-19-associated hospitalization from two CDC VE networks were 52% (95% CI = 47%-57%) and 43% (95% CI = 27%-56%), with a median interval from updated dose of 42 and 47 days, respectively. Updated COVID-19 vaccine provided increased protection against COVID-19-associated ED/UC encounters and hospitalization among immunocompetent adults. These results support CDC recommendations for updated 2023-2024 COVID-19 vaccination. All persons aged ≥6 months should receive updated 2023-2024 COVID-19 vaccine., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Steven Y. Chang reports consulting fees from PureTech Health and Kiniksa Pharmaceuticals, and participation on the data safety monitoring board for an unrelated, local study at Ronald Reagan UCLA Medical Center, outside the submitted work. Manjusha Gaglani reports serving as the Texas Pediatric Society, Texas Chapter of the American Academy of Pediatrics co-chair of the ID and Immunization Committee, outside the submitted work. Adit A. Ginde reports support from Biomeme and Seastar, outside the submitted work. Carlos G. Grijalva reports other funding from Merck, contracts from Syneos Health and the Food and Drug Administration, and grants from National Institutes of Health (NIH) and Agency for Health Care Research and Quality, outside the submitted work. Akram Khan reports grant funding from 4DMedical, Dompe Pharmaceuticals, Ely Lilly, and Roche Pharmaceuticals, outside the submitted work. Adam S. Lauring reports research support from the National Institute of Allergy and Infectious Diseases, Michigan Department of Health and Human Services, Burroughs Wellcome Fund, Flu Lab, and consulting fees from Roche, outside the submitted work. Christopher Mallow reports medical legal consulting, outside the submitted work. Emily T. Martin reports research funding from Merck, outside the submitted work. Ithan D. Peltan reports grant support from NIH, Intermountain Research and Medical Foundation, and Janssen Pharmaceuticals, and funding to his institution from Bluejay Diagnostics and Regeneron, outside the submitted work. Karthik Natarajan reports institutional support from NIH, Office of the Director, the National Center for Advancing Translational Sciences, and the National Heart, Lung, and Blood Institute. Brian E. Dixon reports Institutional support from NIH, National Library of Medicine in the form of a T15 training grant in biomedical informatics, salary support from the U.S. Department of Veterans Affairs, royalties from Elsevier, Inc. for a book on health information technology and from Springer Nature for a book on health information technology. Nicola P. Klein reports support from GSK, Merck, Pfizer, Sanofi Pasteur, and Seqirus for work unrelated to this report. No other potential conflicts of interest were disclosed.

In the United States, annual influenza vaccination is recommended for all persons aged ≥6 months. Using data from four vaccine effectiveness (VE) networks during the 2023-24 influenza season, interim influenza VE was estimated among patients aged ≥6 months with acute respiratory illness-associated medical encounters using a test-negative case-control study design. Among children and adolescents aged 6 months-17 years, VE against influenza-associated outpatient visits ranged from 59% to 67% and against influenza-associated hospitalization ranged from 52% to 61%. Among adults aged ≥18 years, VE against influenza-associated outpatient visits ranged from 33% to 49% and against hospitalization from 41% to 44%. VE against influenza A ranged from 46% to 59% for children and adolescents and from 27% to 46% for adults across settings. VE against influenza B ranged from 64% to 89% for pediatric patients in outpatient settings and from 60% to 78% for all adults across settings. These findings demonstrate that the 2023-24 seasonal influenza vaccine is effective at reducing the risk for medically attended influenza virus infection. CDC recommends that all persons aged ≥6 months who have not yet been vaccinated this season get vaccinated while influenza circulates locally., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Emmanuel B. Walter reports institutional support from Pfizer, Moderna, Seqiris, Clinetic, and Najit Technologies Inc., consulting fees from ILiAD Biotechnologies, payment from the College of Diplomates of the American Board of Pediatric Dentistry, travel support from the American Academy of Pediatrics, and paid compensation for participation on the Vaxcyte Scientific Advisory Board. Yuwei Zhu reports participation on a Vanderbilt University Medical Center Data Safety Monitoring Board. Sara Y. Tartof reports institutional support from Pfizer and Genentech. Samantha M. Olson reports travel support from the Gates Foundation. Nicola P. Klein reports institutional support from Sanofi Pasteur, Merck, Pfizer, Seqirus, and GlaxoSmithKline; membership on an expert panel for a planned hepatitis E Phase II vaccine clinical trial among pregnant women in Pakistan; membership in Western States COVID-19 Scientific Safety Review Workgroup, Board on Population Health and Public Health Practice, National Academies of Science, Engineering and Medicine, and National Vaccine Advisory Committee Safety Subcommittee. Manjusha Gaglani reports receipt of honorarium for educational webinar presentation on respiratory viruses from the Texas Pediatric Society, Texas Chapter of the American Academy of Pediatrics, and serving as co-chair of the Infectious Diseases and Immunization Committee and Chair of the Texas Respiratory Syncytial Virus Taskforce, Texas Pediatric Society. Kevin W. Gibbs reports grants or contracts from the Department of Defense and the National Institutes of Health (NIH) and service as chair of the Vanderbilt University Medical Center Data Safety Monitoring Board. Adit A. Ginde reports institutional support from the NIH, the Department of Defense, AbbVie, and Faron Pharmaceuticals, consulting fees (paid to institution) from Biomeme and Seastar, and participation on data safety monitoring boards for the NIH and Emory University. Richard K. Zimmerman reports institutional support from the NIH and Sanofi Pasteur, and honorarium from Clinical Educational Alliance. Mary A. Staat reports institutional support from NIH, Pfizer, and Merck and royalties for Up-to-Date chapter on International Adoption. Stacey House reports institutional support from Seegene, Inc., Abbot, Healgen, Roche, CorDx, Hologic, Cepheid, Janssen, and Wondfo Biotech. Geoffrey A. Weinberg reports institutional support from the New York State Department of Health AIDS Institute, consulting fees from Inhalon Biopharma for participation on a Scientific Advisory Board, and honoraria from Merck & Company for textbook chapters. Marian G. Michaels reports institutional support from the National Institute on Allergy and Infectious Diseases and complimentary meeting attendance for presentation at the American Transplant Congress on respiratory viruses. Emily T. Martin reports receipt of grants or contracts from Merck. Natasha B. Halasa reports receipt of grants from Sanofi, Quidell, and Merck. Elie A. Saade reports institutional support from Protein Sciences Corporation, consulting fees, honoraria, and travel support from Johnson & Johnson and participation on a Johnson & Johnson Data Safety Monitoring Board. No other potential conflicts of interest were disclosed.

Background: Immunocompromised (IC) persons are at increased risk for severe COVID-19 outcomes and are less protected by 1-2 COVID-19 vaccine doses than are immunocompetent (non-IC) persons. We compared vaccine effectiveness (VE) against medically attended COVID-19 of 2-3 mRNA and 1-2 viral-vector vaccine doses between IC and non-IC adults., Methods: Using a test-negative design among eight VISION Network sites, VE against laboratory-confirmed COVID-19-associated emergency department (ED) or urgent care (UC) events and hospitalizations from 26 August-25 December 2021 was estimated separately among IC and non-IC adults and among specific IC condition subgroups. Vaccination status was defined using number and timing of doses. VE for each status (versus unvaccinated) was adjusted for age, geography, time, prior positive test result, and local SARS-CoV-2 circulation., Results: We analyzed 8,848 ED/UC events and 18,843 hospitalizations among IC patients and 200,071 ED/UC events and 70,882 hospitalizations among non-IC patients. Among IC patients, 3-dose mRNA VE against ED/UC (73% [95% CI: 64-80]) and hospitalization (81% [95% CI: 76-86]) was lower than that among non-IC patients (ED/UC: 94% [95% CI: 93-94]; hospitalization: 96% [95% CI: 95-97]). Similar patterns were observed for viral-vector vaccines. Transplant recipients had lower VE than other IC subgroups., Conclusions: During B.1.617.2 (Delta) variant predominance, IC adults received moderate protection against COVID-19-associated medical events from three mRNA doses, or one viral-vector dose plus a second dose of any product. However, protection was lower in IC versus non-IC patients, especially among transplant recipients, underscoring the need for additional protection among IC adults., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Nicola P. Klein reports institutional support from Pfizer for COVID-19 vaccine clinical trials. Charlene McEvoy reports institutional support from AstraZeneca for an AZD1222 COVID-19 vaccine trial. Suchitra Rao reports grant support from GlaxoSmithKline and Biofire Diagnostics. Dr. Brian Dixon reports past consulting fees from Merck & Co. for serving on an advisory panel for HPV vaccination. Manjusha Gaglani reports past support from the CDC for the IVY-3 vaccine research. Kempapura Murthy reports past support from the CDC HAIVEN – Hospitalized Adult Influenza Vaccine Effectiveness Network. All other authors report no disclosures relevant to the current manuscript., (Copyright © 2023. Published by Elsevier Ltd.)

On June 19, 2022, the original monovalent mRNA COVID-19 vaccines were approved as a primary series for children aged 6 months-4 years (Pfizer-BioNTech) and 6 months-5 years (Moderna) based on safety, immunobridging, and limited efficacy data from clinical trials. On December 9, 2022, CDC expanded recommendations for use of updated bivalent vaccines to children aged ≥6 months. mRNA COVID-19 vaccine effectiveness (VE) against emergency department or urgent care (ED/UC) encounters was evaluated within the VISION Network during July 4, 2022-June 17, 2023, among children with COVID-19-like illness aged 6 months-5 years. Among children aged 6 months-5 years who received molecular SARS-CoV-2 testing during August 1, 2022-June 17, 2023, VE of 2 monovalent Moderna doses against ED/UC encounters was 29% (95% CI = 12%-42%) ≥14 days after dose 2 (median = 100 days after dose 2; IQR = 63-155 days). Among children aged 6 months-4 years with a COVID-19-like illness who received molecular testing during September 19, 2022-June 17, 2023, VE of 3 monovalent Pfizer-BioNTech doses was 43% (95% CI = 17%-61%) ≥14 days after dose 3 (median = 75 days after dose 3; IQR = 40-139 days). Effectiveness of ≥1 bivalent dose, comparing children with at least a complete primary series and ≥1 bivalent dose to unvaccinated children, irrespective of vaccine manufacturer, was 80% (95% CI = 42%-96%) among children aged 6 months-5 years a median of 58 days (IQR = 32-83 days) after the dose. All children should stay up to date with recommended COVID-19 vaccines, including initiation of COVID-19 vaccination immediately when they are eligible., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Nicola P. Klein reports institutional support from Pfizer, Merck, GSK, Sanofi Pasteur, and Protein Sciences (now Sanofi Pasteur). Allison L. Naleway reports institutional support from Pfizer for an unrelated study of meningococcal B vaccine safety during pregnancy study and from Vir Biotechnology for an unrelated influenza study. Suchitra Rao reports grant support from GSK. No other potential conflicts of interest were disclosed.

Background: Following historically low influenza activity during the 2020-2021 season, the United States saw an increase in influenza circulating during the 2021-2022 season. Most viruses belonged to the influenza A(H3N2) 3C.2a1b 2a.2 subclade., Methods: We conducted a test-negative case-control analysis among adults ≥18 years of age at 3 sites within the VISION Network. Encounters included emergency department/urgent care (ED/UC) visits or hospitalizations with ≥1 acute respiratory illness (ARI) discharge diagnosis codes and molecular testing for influenza. Vaccine effectiveness (VE) was calculated by comparing the odds of influenza vaccination ≥14 days before the encounter date between influenza-positive cases (type A) and influenza-negative and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-negative controls, applying inverse probability-to-be-vaccinated weights, and adjusting for confounders., Results: In total, 86 732 ED/UC ARI-associated encounters (7696 [9%] cases) and 16 805 hospitalized ARI-associated encounters (649 [4%] cases) were included. VE against influenza-associated ED/UC encounters was 25% (95% confidence interval (CI), 20%-29%) and 25% (95% CI, 11%-37%) against influenza-associated hospitalizations. VE against ED/UC encounters was lower in adults ≥65 years of age (7%; 95% CI, -5% to 17%) or with immunocompromising conditions (4%; 95% CI, -45% to 36%)., Conclusions: During an influenza A(H3N2)-predominant influenza season, modest VE was observed. These findings highlight the need for improved vaccines, particularly for A(H3N2) viruses that are historically associated with lower VE., Competing Interests: Potential conflicts of interest. S. R. received grants from GlaxoSmithKline. A. L. N. received grants from Pfizer and Vir Biotechnology. C. M. received grants from AstraZeneca. N. P. K. received grants from Pfizer, Merck, GlaxoSmithKline, and Sanofi Pasteur. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2023.)

Background: Understanding the usefulness of additional COVID-19 vaccine doses-particularly given varying disease incidence-is needed to support public health policy. We characterize the benefits of COVID-19 booster doses using number needed to vaccinate (NNV) to prevent one COVID-19-associated hospitalization or emergency department encounter., Methods: We conducted a retrospective cohort study of immunocompetent adults at five health systems in four U.S. states during SARS-CoV-2 Omicron BA.1 predominance (December 2021-February 2022). Included patients completed a primary mRNA COVID-19 vaccine series and were either eligible to or received a booster dose. NNV were estimated using hazard ratios for each outcome (hospitalization and emergency department encounters), with results stratified by three 25-day periods and site., Findings: 1,285,032 patients contributed 938 hospitalizations and 2076 emergency department encounters. 555,729 (43.2%) patients were aged 18-49 years, 363,299 (28.3%) 50-64 years, and 366,004 (28.5%) ≥65 years. Most patients were female (n = 765,728, 59.6%), White (n = 990,224, 77.1%), and non-Hispanic (n = 1,063,964, 82.8%). 37.2% of patients received a booster and 62.8% received only two doses. Median estimated NNV to prevent one hospitalization was 205 (range 44-615) and NNV was lower across study periods for adults aged ≥65 years (110, 46, and 88, respectively) and those with underlying medical conditions (163, 69, and 131, respectively). Median estimated NNV to prevent one emergency department encounter was 156 (range 75-592)., Interpretation: The number of patients needed to receive a booster dose was highly dependent on local disease incidence, outcome severity, and patient risk factors for moderate-to-severe disease., Funding: Funding was provided by the Centers for Disease Control and Prevention though contract 75D30120C07986 to Westat, Inc. and contract 75D30120C07765 to Kaiser Foundation Hospitals., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. M.G. reports additional contracts with CDC Ambulatory US Flu/COVID VE Network, HAIVEN Adult Inpatient Flu/COVID VE, IVY-3 PHS, and RECOVER. A.L.N. reports research funding from Pfizer for an unrelated study of meningococcal B vaccine safety during pregnancy and Vir Biotechnology for an unrelated influenza study. S.A.I. reports an additional contract with Centers for Disease Control and Prevention, 200-2012-53584 (Vaccine Safety Datalink). A.K. reports a subcontract through HealthPartners for VISION payment made to Children’s Minnesota. B.E.D. reports a grant from NIH to evaluate HIE technologies, a grant from CDC to use HIE data for public health surveillance, an R21 grant from U.S. Agency for Healthcare Research Quality to evaluate HIE technologies, a grant from the U.S Department of Veterans Affairs to evaluate HIE technologies, royalties from Elsevier and Springer Nature for books on HIE and Public Health Informatics, and consulting fees for advisory panel on HPV vaccination from Merk and Co. K.M. reports two additional contracts with CDC: Ambulatory US Flu VE Network and HAIVEN Hospitalized Adult Influenza Vaccine Effectiveness Network. J.J.R., E.A.K.R., A.H., J.K., S.W.B., and M.M.D. report payments made to Westat via CDC Contract #200-2019-F-06819. B.F., E.H., E.S., K.N., K.D., C.R., C.S-A., M.B.D., T.C.O., N.G., J.N., J.A., N.R.V., and P.J.E. report payments made to their institution by CDC via Westat. No other potential conflicts of interest were disclosed.

Objectives: We assessed BNT162b2 vaccine effectiveness (VE) against mild to moderate and severe coronavirus disease 2019 (COVID-19) in children and adolescents through the Omicron BA.4/BA.5 period., Methods: Using VISION Network records from April 2021 to September 2022, we conducted a test-negative, case-control study assessing VE against COVID-19-associated emergency department/urgent care (ED/UC) encounters and hospitalizations using logistic regression, conditioned on month and site, adjusted for covariates., Results: We compared 9800 ED/UC cases with 70 232 controls, and 305 hospitalized cases with 2612 controls. During Delta, 2-dose VE against ED/UC encounters at 12 to 15 years was initially 93% (95% confidence interval 89 to 95), waning to 77% (69% to 84%) after ≥150 days. At ages 16 to 17, VE was initially 93% (86% to 97%), waning to 72% (63% to 79%) after ≥150 days. During Omicron, VE at ages 12 to 15 was initially 64% (44% to 77%), waning to 13% (3% to 23%) after ≥150 days; at ages 16 to 17 VE was 31% (10% to 47%) during days 60 to 149, waning to 7% (-8 to 20%) after 150 days. A monovalent booster increased VE to 54% (40% to 65%) at ages 12 to 15 and 46% (30% to 58%) at ages 16 to 17. At ages 5 to 11, 2-dose VE was 49% (33% to 61%) initially and 41% (29% to 51%) after 150 days. During Delta, VE against hospitalizations at ages 12 to 17 was high (>97%), and at ages 16 to 17 remained 98% (73% to 100%) beyond 150 days; during Omicron, hospitalizations were too infrequent to precisely estimate VE., Conclusions: BNT162b2 protected children and adolescents against mild to moderate and severe COVID-19. VE was lower during Omicron predominance including BA.4/BA.5, waned after dose 2 but increased after a monovalent booster. Children and adolescents should receive all recommended COVID-19 vaccinations., (Copyright © 2023 by the American Academy of Pediatrics.)

During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of the sequenced viral genomes in the United States, with further Omicron sublineage diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral SARS-CoV-2 strain component plus an updated component of the Omicron BA.4/BA.5 sublineages. On September 1, 2022, a single bivalent booster dose was recommended for adults who had completed a primary vaccination series (with or without subsequent booster doses), with the last dose administered ≥2 months earlier (1). During September 13-November 18, the VISION Network evaluated vaccine effectiveness (VE) of a bivalent mRNA booster dose (after 2, 3, or 4 monovalent doses) compared with 1) no previous vaccination and 2) previous receipt of 2, 3, or 4 monovalent-only mRNA vaccine doses, among immunocompetent adults aged ≥18 years with an emergency department/urgent care (ED/UC) encounter or hospitalization for a COVID-19-like illness. † VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated ED/UC encounters was 56% compared with no vaccination, 32% compared with monovalent vaccination only with last dose 2-4 months earlier, and 50% compared with monovalent vaccination only with last dose ≥11 months earlier. VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated hospitalizations was 59% compared with no vaccination, 42% compared with monovalent vaccination only with last dose 5-7 months earlier, and 48% compared with monovalent vaccination only with last dose ≥11 months earlier. Bivalent vaccines administered after 2, 3, or 4 monovalent doses were effective in preventing medically attended COVID-19 compared with no vaccination and provided additional protection compared with past monovalent vaccination only, with relative protection increasing with time since receipt of the last monovalent dose. All eligible persons should stay up to date with recommended COVID-19 vaccinations, including receiving a bivalent booster dose. Persons should also consider taking additional precautions to avoid respiratory illness this winter season, such as masking in public indoor spaces, especially in areas where COVID-19 community levels are high., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Nicola P. Klein received grants from Pfizer, Merck, GlaxoSmithKline, and Sanofi Pasteur. Allison L. Naleway received grants from Pfizer and Vir Biotechnology. Suchitra Rao received grants from GlaxoSmithKline. Charlene McEvoy received grants from AztraZeneca. No other potential conflicts of interest were disclosed.

Importance: Recent SARS-CoV-2 Omicron variant sublineages, including BA.4 and BA.5, may be associated with greater immune evasion and less protection against COVID-19 after vaccination., Objectives: To evaluate the estimated vaccine effectiveness (VE) of 2, 3, or 4 doses of COVID-19 mRNA vaccination among immunocompetent adults during a period of BA.4 or BA.5 predominant circulation; and to evaluate the relative severity of COVID-19 in hospitalized patients across Omicron BA.1, BA.2 or BA.2.12.1, and BA.4 or BA.5 sublineage periods., Design, Setting, and Participants: This test-negative case-control study was conducted in 10 states with data from emergency department (ED) and urgent care (UC) encounters and hospitalizations from December 16, 2021, to August 20, 2022. Participants included adults with COVID-19-like illness and molecular testing for SARS-CoV-2. Data were analyzed from August 2 to September 21, 2022., Exposures: mRNA COVID-19 vaccination., Main Outcomes and Measures: The outcomes of interest were COVID-19 ED or UC encounters, hospitalizations, and admission to the intensive care unit (ICU) or in-hospital death. VE associated with protection against medically attended COVID-19 was estimated, stratified by care setting and vaccine doses (2, 3, or 4 doses vs 0 doses as the reference group). Among hospitalized patients with COVID-19, demographic and clinical characteristics and in-hospital outcomes were compared across sublineage periods., Results: During the BA.4 and BA.5 predominant period, there were 82 229 eligible ED and UC encounters among patients with COVID-19-like illness (median [IQR] age, 51 [33-70] years; 49 682 [60.4%] female patients), and 19 114 patients (23.2%) had test results positive for SARS-CoV-2; among 21 007 hospitalized patients (median [IQR] age, 71 [58-81] years; 11 209 [53.4%] female patients), 3583 (17.1 %) had test results positive for SARS-CoV-2. Estimated VE against hospitalization was 25% (95% CI, 17%-32%) for receipt of 2 vaccine doses at 150 days or more after receipt, 68% (95% CI, 50%-80%) for a third dose 7 to 119 days after receipt, and 36% (95% CI, 29%-42%) for a third dose 120 days or more (median [IQR], 235 [204-262] days) after receipt. Among patients aged 65 years or older who had received a fourth vaccine dose, VE was 66% (95% CI, 53%-75%) at 7 to 59 days after vaccination and 57% (95% CI, 44%-66%) at 60 days or more (median [IQR], 88 [75-105] days) after vaccination. Among hospitalized patients with COVID-19, ICU admission or in-hospital death occurred in 21.4% of patients during the BA.1 period vs 14.7% during the BA.4 and BA.5 period (standardized mean difference: 0.17)., Conclusions and Relevance: In this case-control study of COVID-19 vaccines and illness, VE associated with protection against medically attended COVID-19 illness was lower with increasing time since last dose; estimated VE was higher after receipt of 1 or 2 booster doses compared with a primary series alone.

During June-October 2022, the SARS-CoV-2 Omicron BA.5 sublineage accounted for most of the sequenced viral genomes in the United States, with further Omicron sublineage diversification through November 2022.* Bivalent mRNA vaccines contain an ancestral SARS-CoV-2 strain component plus an updated component of the Omicron BA.4/BA.5 sublineages. On September 1, 2022, a single bivalent booster dose was recommended for adults who had completed a primary vaccination series (with or without subsequent booster doses), with the last dose administered ≥2 months earlier (1). During September 13-November 18, the VISION Network evaluated vaccine effectiveness (VE) of a bivalent mRNA booster dose (after 2, 3, or 4 monovalent doses) compared with 1) no previous vaccination and 2) previous receipt of 2, 3, or 4 monovalent-only mRNA vaccine doses, among immunocompetent adults aged ≥18 years with an emergency department/urgent care (ED/UC) encounter or hospitalization for a COVID-19-like illness. † VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated ED/UC encounters was 56% compared with no vaccination, 31% compared with monovalent vaccination only with last dose 2-4 months earlier, and 50% compared with monovalent vaccination only with last dose ≥11 months earlier. VE of a bivalent booster dose (after 2, 3, or 4 monovalent doses) against COVID-19-associated hospitalizations was 57% compared with no vaccination, 38% compared with monovalent vaccination only with last dose 5-7 months earlier, and 45% compared with monovalent vaccination only with last dose ≥11 months earlier. Bivalent vaccines administered after 2, 3, or 4 monovalent doses were effective in preventing medically attended COVID-19 compared with no vaccination and provided additional protection compared with past monovalent vaccination only, with relative protection increasing with time since receipt of the last monovalent dose. All eligible persons should stay up to date with recommended COVID-19 vaccinations, including receiving a bivalent booster dose. Persons should also consider taking additional precautions to avoid respiratory illness this winter season, such as masking in public indoor spaces, especially in areas where COVID-19 community levels are high., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Nicola P. Klein received grants from Pfizer, Merck, GlaxoSmithKline, and Sanofi Pasteur. Allison L. Naleway received grants from Pfizer and Vir Biotechnology. Suchitra Rao received grants from GlaxoSmithKline. Charlene McEvoy received grants from AztraZeneca. No other potential conflicts of interest were disclosed.

Persons with moderate-to-severe immunocompromising conditions might have reduced protection after COVID-19 vaccination, compared with persons without immunocompromising conditions (1-3). On August 13, 2021, the Advisory Committee on Immunization Practices (ACIP) recommended that adults with immunocompromising conditions receive an expanded primary series of 3 doses of an mRNA COVID-19 vaccine. ACIP followed with recommendations on September 23, 2021, for a fourth (booster) dose and on September 1, 2022, for a new bivalent mRNA COVID-19 vaccine booster dose, containing components of the BA.4 and BA.5 sublineages of the Omicron (B.1.1.529) variant (4). Data on vaccine effectiveness (VE) of monovalent COVID-19 vaccines among persons with immunocompromising conditions since the emergence of the Omicron variant in December 2021 are limited. In the multistate VISION Network, § monovalent 2-, 3-, and 4-dose mRNA VE against COVID-19-related hospitalization were estimated among adults with immunocompromising conditions ¶ hospitalized with COVID-19-like illness,** using a test-negative design comparing odds of previous vaccination among persons with a positive or negative molecular test result (case-patients and control-patients) for SARS-CoV-2 (the virus that causes COVID-19). During December 16, 2021-August 20, 2022, among SARS-CoV-2 test-positive case-patients, 1,815 (36.3%), 1,387 (27.7%), 1,552 (31.0%), and 251 (5.0%) received 0, 2, 3, and 4 mRNA COVID-19 vaccine doses, respectively. Among test-negative control-patients during this period, 6,928 (23.7%), 7,411 (25.4%), 12,734 (43.6%), and 2,142 (7.3%) received these respective doses. Overall, VE against COVID-19-related hospitalization among adults with immunocompromising conditions hospitalized for COVID-like illness during Omicron predominance was 36% ≥14 days after dose 2, 69% 7-89 days after dose 3, and 44% ≥90 days after dose 3. Restricting the analysis to later periods when Omicron sublineages BA.2/BA.2.12.1 and BA.4/BA.5 were predominant and 3-dose recipients were eligible to receive a fourth dose, VE was 32% ≥90 days after dose 3 and 43% ≥7 days after dose 4. Protection offered by vaccination among persons with immunocompromising conditions during Omicron predominance was moderate even after a 3-dose monovalent primary series or booster dose. Given the incomplete protection against hospitalization afforded by monovalent COVID-19 vaccines, persons with immunocompromising conditions might benefit from updated bivalent vaccine booster doses that target recently circulating Omicron sublineages, in line with ACIP recommendations. Further, additional protective recommendations for persons with immunocompromising conditions, including the use of prophylactic antibody therapy, early access to and use of antivirals, and enhanced nonpharmaceutical interventions such as well-fitting masks or respirators, should also be considered., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Brian E. Dixon reported grant support from the National Institutes of Health, Agency for Healthcare Research and Quality, and the U.S. Department of Veterans Affairs; personal fees from Elsevier and Springer Nature; and consulting fees from Merck. Nicola P. Klein reported institutional grant support from Pfizer, Inc., Merck, GSK, and Sanofi Pasteur. Allison L. Naleway reported institutional support from Pfizer, Inc. and Vir Biotechnology. Suchitra Rao reported grant support from GSK. Charlene McEvoy reported institutional support from AstraZeneca. No other potential conflicts of interest were disclosed.

Background: Limited data exist on population-based risks and risk ratios (RRs) of coronavirus disease 2019 (COVID-19)-associated hospitalizations and clinical outcomes stratified by age and race/ethnicity., Methods: Using data from electronic health records and claims from 4 US health systems for the period March 2020-March 2021, we calculated risk and RR by age and race/ethnicity for COVID-19-associated hospitalizations and clinical outcomes among adults (≥18 years). COVID-19-associated hospitalizations were defined based on COVID-19 discharge codes or a positive severe acute respiratory syndrome coronavirus 2 result. Proportions of acute exacerbations of underlying conditions were estimated among hospitalized patients with select underlying conditions, stratified by age and race/ethnicity., Results: Among 2.6 million adults included in the patient cohort, 6879 had COVID-19-associated hospitalizations during March 2020-March 2021 (risk: 264 per 100 000 population). Compared with younger, non-Hispanic White adults, non-Hispanic Black and Hispanic adults aged ≥65 years had the highest hospitalization risk ratios (RR, 8.6; 95% CI, 7.6-9.9; and RR, 9.3; 95% CI, 8.5-10.3, respectively). Among hospitalized adults with COVID-19 and renal disease or cardiovascular disease, the highest proportion of acute renal failure (55.5%) or congestive heart failure (43.9%) occurred in older, non-Hispanic Black patients. Among hospitalized adults with chronic lung disease or asthma, the highest proportion of respiratory failure (62.9%) or asthma exacerbation (66.7%) occurred in older, Hispanic patients., Conclusions: During the first year of the US COVID-19 pandemic in this cohort, older non-Hispanic Black and Hispanic adults had the highest relative risks of COVID-19-associated hospitalization and adverse outcomes and, among those with select underlying conditions, the highest occurrences of acute exacerbations of underlying conditions., Competing Interests: Potential conflicts of interest. Allison Naleway received research funding from Pfizer and Vir Biotechnology unrelated to the study. All other authors report no potential conflicts. All authors have submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. Conflicts that the editors consider relevant to the content of the manuscript have been disclosed., (Published by Oxford University Press on behalf of Infectious Diseases Society of America 2022.)

The Omicron variant (B.1.1.529) of SARS-CoV-2, the virus that causes COVID-19, was first identified in the United States in November 2021, with the BA.1 sublineage (including BA.1.1) causing the largest surge in COVID-19 cases to date. Omicron sublineages BA.2 and BA.2.12.1 emerged later and by late April 2022, accounted for most cases.* Estimates of COVID-19 vaccine effectiveness (VE) can be reduced by newly emerging variants or sublineages that evade vaccine-induced immunity (1), protection from previous SARS-CoV-2 infection in unvaccinated persons (2), or increasing time since vaccination (3). Real-world data comparing VE during the periods when the BA.1 and BA.2/BA.2.12.1 predominated (BA.1 period and BA.2/BA.2.12.1 period, respectively) are limited. The VISION network † examined 214,487 emergency department/urgent care (ED/UC) visits and 58,782 hospitalizations with a COVID-19-like illness § diagnosis among 10 states during December 18, 2021-June 10, 2022, to evaluate VE of 2, 3, and 4 doses of mRNA COVID-19 vaccines (BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]) compared with no vaccination among adults without immunocompromising conditions. VE against COVID-19-associated hospitalization 7-119 days and ≥120 days after receipt of dose 3 was 92% (95% CI = 91%-93%) and 85% (95% CI = 81%-89%), respectively, during the BA.1 period, compared with 69% (95% CI = 58%-76%) and 52% (95% CI = 44%-59%), respectively, during the BA.2/BA.2.12.1 period. Patterns were similar for ED/UC encounters. Among adults aged ≥50 years, VE against COVID-19-associated hospitalization ≥120 days after receipt of dose 3 was 55% (95% CI = 46%-62%) and ≥7 days (median = 27 days) after a fourth dose was 80% (95% CI = 71%-85%) during BA.2/BA.2.12.1 predominance. Immunocompetent persons should receive recommended COVID-19 booster doses to prevent moderate to severe COVID-19, including a first booster dose for all eligible persons and second booster dose for adults aged ≥50 years at least 4 months after an initial booster dose. Booster doses should be obtained immediately when persons become eligible. ¶ ., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Stephanie A. Irving reports institutional support from Westat. Nicola P. Klein reports institutional support from Pfizer, Merck, GlaxoSmithKline, Sanofi Pasteur, and Protein Science, unrelated to the current work, and institutional support from Pfizer for COVID-19 vaccine clinical trials. Allison L. Naleway reports institutional support from Pfizer for a study of meningococcal B vaccine safety during pregnancy, unrelated to the current work. Charlene McEvoy reports institutional support from AstraZeneca for an AZD1222 COVID-19 vaccine trial. Suchitra Rao reports grant support from GlaxoSmithKline and Biofire Diagnostics. No other potential conflicts of interest were disclosed.

Background: Many countries recommend influenza vaccination during pregnancy. Despite this recommendation, influenza vaccine among pregnant individuals remains under-utilized and uptake varies by country. Factors associated with influenza vaccine uptake during pregnancy may also vary across countries., Methods: As members of the Pregnancy Influenza Vaccine Effectiveness Network (PREVENT), five sites from four countries (Australia, Canada, Israel, and the United States) retrospectively identified cohorts of individuals aged 18-50 years who were pregnant during pre-defined influenza seasons. Influenza vaccine coverage estimates were calculated for the 2010-11 through 2015-16 northern hemisphere and the 2012 through 2015 southern hemisphere influenza seasons, by site. Sites used electronic health records, administrative data, and immunization registries to collect information on pregnancy, health history, demographics, and vaccination status. Each season, vaccination coverage was calculated as the percentage of individuals who received influenza vaccine among the individuals in the cohort that season. Characteristics were compared between those vaccinated and unvaccinated, by site., Results: More than two million pregnancies were identified over the study period. Influenza vaccination coverage ranged from 5% to 58% across sites and seasons. Coverage increased consistently over the study period at three of the five sites (Western Australia, Alberta, and Israel), and was highest in all seasons at the United States study site (39-58%). Associations with vaccination varied by country and across seasons; where available, parity >0, presence of a high-risk medical condition, and urban residence were consistently associated with increased likelihood of vaccination., Conclusions: Though increasing, uptake of influenza vaccine among pregnant individuals remains lower than recommended. Coverage varied substantially by country, suggesting an ongoing need for targeted strategies to improve influenza vaccine uptake in this population., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Dr. Naleway and Dr. Katz each report unrelated research support from Pfizer. Dr. Klein reports unrelated research support from Sanofi Pasteur, Protein Science (now Sanofi Pasteur), GlaxoSmithKline, Merck & Co, and Pfizer. All additional authors have no conflicts to disclose., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Previous infection with SARS-CoV-2 (the virus that causes COVID-19) or COVID-19 vaccination can provide immunity and protection from subsequent SARS-CoV-2 infection and illness. CDC used data from the VISION Network* to examine hospitalizations in adults with COVID-19-like illness and compared the odds of receiving a positive SARS-CoV-2 test result, and thus having laboratory-confirmed COVID-19, between unvaccinated patients with a previous SARS-CoV-2 infection occurring 90-179 days before COVID-19-like illness hospitalization, and patients who were fully vaccinated with an mRNA COVID-19 vaccine 90-179 days before hospitalization with no previous documented SARS-CoV-2 infection. Hospitalized adults aged ≥18 years with COVID-19-like illness were included if they had received testing at least twice: once associated with a COVID-19-like illness hospitalization during January-September 2021 and at least once earlier (since February 1, 2020, and ≥14 days before that hospitalization). Among COVID-19-like illness hospitalizations in persons whose previous infection or vaccination occurred 90-179 days earlier, the odds of laboratory-confirmed COVID-19 (adjusted for sociodemographic and health characteristics) among unvaccinated, previously infected adults were higher than the odds among fully vaccinated recipients of an mRNA COVID-19 vaccine with no previous documented infection (adjusted odds ratio [aOR] = 5.49; 95% confidence interval [CI] = 2.75-10.99). These findings suggest that among hospitalized adults with COVID-19-like illness whose previous infection or vaccination occurred 90-179 days earlier, vaccine-induced immunity was more protective than infection-induced immunity against laboratory-confirmed COVID-19. All eligible persons should be vaccinated against COVID-19 as soon as possible, including unvaccinated persons previously infected with SARS-CoV-2., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Stephanie A. Irving reports support from Westat to Kaiser Permanente Northwest Center for Health Research. Nicola P. Klein reports support from Pfizer to Kaiser Permanente, Northern California for COVID-19 vaccine clinical trials, and institutional support from Merck, GlaxoSmithKline, and Sanofi Pasteur outside the current study. Charlene McEvoy reports support from AstraZeneca to HealthPartners Institute for COVID-19 vaccine trials. Allison L. Naleway reports Pfizer Research funding to Kaiser Permanente Northwest for unrelated study of meningococcal B vaccine safety during pregnancy. Suchitra Rao reports grants from GlaxoSmithKline and Biofire Diagnostics. No other potential conflicts of interest were disclosed.

Immunocompromised persons, defined as those with suppressed humoral or cellular immunity resulting from health conditions or medications, account for approximately 3% of the U.S. adult population (1). Immunocompromised adults are at increased risk for severe COVID-19 outcomes (2) and might not acquire the same level of protection from COVID-19 mRNA vaccines as do immunocompetent adults (3,4). To evaluate vaccine effectiveness (VE) among immunocompromised adults, data from the VISION Network* on hospitalizations among persons aged ≥18 years with COVID-19-like illness from 187 hospitals in nine states during January 17-September 5, 2021 were analyzed. Using selected discharge diagnoses, † VE against COVID-19-associated hospitalization conferred by completing a 2-dose series of an mRNA COVID-19 vaccine ≥14 days before the index hospitalization date § (i.e., being fully vaccinated) was evaluated using a test-negative design comparing 20,101 immunocompromised adults (10,564 [53%] of whom were fully vaccinated) and 69,116 immunocompetent adults (29,456 [43%] of whom were fully vaccinated). VE of 2 doses of mRNA COVID-19 vaccine against COVID-19-associated hospitalization was lower among immunocompromised patients (77%; 95% confidence interval [CI] = 74%-80%) than among immunocompetent patients (90%; 95% CI = 89%-91%). This difference persisted irrespective of mRNA vaccine product, age group, and timing of hospitalization relative to SARS-CoV-2 (the virus that causes COVID-19) B.1.617.2 (Delta) variant predominance in the state of hospitalization. VE varied across immunocompromising condition subgroups, ranging from 59% (organ or stem cell transplant recipients) to 81% (persons with a rheumatologic or inflammatory disorder). Immunocompromised persons benefit from mRNA COVID-19 vaccination but are less protected from severe COVID-19 outcomes than are immunocompetent persons, and VE varies among immunocompromised subgroups. Immunocompromised persons receiving mRNA COVID-19 vaccines should receive 3 doses and a booster, consistent with CDC recommendations (5), practice nonpharmaceutical interventions, and, if infected, be monitored closely and considered early for proven therapies that can prevent severe outcomes., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Allison L. Naleway reports institutional support from Pfizer outside the submitted work. Anupam B. Kharbanda reports institutional support through HealthPartners to Children’s Minnesota for VISION. Charlene McEvoy reports institutional support from AstraZeneca for the AZD1222 COVID-19 vaccine trial. Jill Ferdinands reports travel support from Institute for Influenza Epidemiology, funded in part by Sanofi Pasteur. Nicola P. Klein reports institutional support from Pfizer for COVID-19 vaccine clinical trials and institutional support from Pfizer, Merck, GlaxoSmithKline, Sanofi Pasteur, and Protein Sciences (now Sanofi Pasteur) outside the submitted work. Suchitra Rao reports grant support from GlaxoSmithKline and Biofire Diagnostics. No other potential conflicts of interest were disclosed.

Background: There are limited data on the effectiveness of the vaccines against symptomatic coronavirus disease 2019 (Covid-19) currently authorized in the United States with respect to hospitalization, admission to an intensive care unit (ICU), or ambulatory care in an emergency department or urgent care clinic., Methods: We conducted a study involving adults (≥50 years of age) with Covid-19-like illness who underwent molecular testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We assessed 41,552 admissions to 187 hospitals and 21,522 visits to 221 emergency departments or urgent care clinics during the period from January 1 through June 22, 2021, in multiple states. The patients' vaccination status was documented in electronic health records and immunization registries. We used a test-negative design to estimate vaccine effectiveness by comparing the odds of a positive test for SARS-CoV-2 infection among vaccinated patients with those among unvaccinated patients. Vaccine effectiveness was adjusted with weights based on propensity-for-vaccination scores and according to age, geographic region, calendar time (days from January 1, 2021, to the index date for each medical visit), and local virus circulation., Results: The effectiveness of full messenger RNA (mRNA) vaccination (≥14 days after the second dose) was 89% (95% confidence interval [CI], 87 to 91) against laboratory-confirmed SARS-CoV-2 infection leading to hospitalization, 90% (95% CI, 86 to 93) against infection leading to an ICU admission, and 91% (95% CI, 89 to 93) against infection leading to an emergency department or urgent care clinic visit. The effectiveness of full vaccination with respect to a Covid-19-associated hospitalization or emergency department or urgent care clinic visit was similar with the BNT162b2 and mRNA-1273 vaccines and ranged from 81% to 95% among adults 85 years of age or older, persons with chronic medical conditions, and Black or Hispanic adults. The effectiveness of the Ad26.COV2.S vaccine was 68% (95% CI, 50 to 79) against laboratory-confirmed SARS-CoV-2 infection leading to hospitalization and 73% (95% CI, 59 to 82) against infection leading to an emergency department or urgent care clinic visit., Conclusions: Covid-19 vaccines in the United States were highly effective against SARS-CoV-2 infection requiring hospitalization, ICU admission, or an emergency department or urgent care clinic visit. This vaccine effectiveness extended to populations that are disproportionately affected by SARS-CoV-2 infection. (Funded by the Centers for Disease Control and Prevention.)., (Copyright © 2021 Massachusetts Medical Society.)

The revised Standards for Adult Immunization Practice ("Standards"), published in 2014, recommend routine vaccination assessment, strong provider recommendation, vaccine administration or referral, and documentation of vaccines administered into immunization information systems (IIS). We assessed clinician and pharmacist implementation of the Standards in the United States from 2016 to 2018. Participating clinicians (family and internal medicine physicians, obstetricians-gynecologists, specialty physicians, physician assistants, and nurse practitioners) and pharmacists responded using an internet panel survey. Weighted proportion of clinicians and pharmacists reporting full implementation of each component of the Standards were calculated. Adjusted prevalence ratio (APR) estimates of practice characteristics associated with self-reported implementation of the Standards are also presented. Across all medical specialties, the percentages of clinicians and pharmacists implementing the vaccine assessment and recommendation components of the Standards were >80.0%. However, due to low IIS documentation, full implementation of the Standards was low overall, ranging from 30.4% for specialty medicine to 45.8% in family medicine clinicians. The presence of an immunization champion (APR, 1.40 [95% confidence interval {CI}, 1.26 to 1.54]), use of standing orders (APR, 1.41 [95% CI, 1.27 to 1.57]), and use of a patient reminder-recall system (APR, 1.39 [95% CI, 1.26 to 1.54]) were positively associated with adherence to the Standards by clinicians. Similar results were observed for pharmacists. Nonetheless, vaccination improvement strategies, i.e., having standing orders in place, empowering an immunization champion, and using patient recall-reminder systems were underutilized in clinical settings; full implementation of the Standards was inconsistent across all health care provider practices., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Regarding the present manuscript, the following co-authors do not report and conflicts of interest: Charleigh J. Granade, Amy Parker-Fiebelkorn, Carla L. Black, Anup Srivastav, Chelsea S. Lutz, Carolyn B. Bridges, and David K. Kim. Because the data presented in this manuscript was collected through a contractual agreement between CDC and Abt. Associates, the following co-authors report a conflict of interest: Sarah W. Ball, Rebecca G. Devlin, and Ann J. Cloud.., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Objectives: Findings during the 2009 pandemic suggest severe maternal infection with pandemic influenza had adverse perinatal health consequences. Limited data exist evaluating the perinatal health effects of severe seasonal influenza and non-influenza infections during pregnancy., Methods: A retrospective cohort of pregnant women from Australia, Canada, Israel, and the United States was established using birth records to identify pregnancies and birth outcomes and hospital and laboratory testing records to identify influenza and non-influenza associated acute respiratory or febrile illness (ARFI) hospitalizations. ARFI hospitalized women were matched to non-hospitalized women (1:4) by country and season of conception. Log-binomial regression was used to estimate the relative risk (aRR) of preterm birth (PTB), small-for-gestational-age (SGA), and low birthweight (LBW) birth, adjusting for pre-existing medical conditions, maternal age, and parity., Results: 950 pregnant women hospitalized with an ARFI were matched with 3,800 non-hospitalized pregnant women. Compared to non-hospitalized women, risk of PTB was greater among women hospitalized with influenza-associated ARFI (aRR: 1.57; 95% CI: 1.15-2.15) and non-influenza ARFI (aRR: 2.78; 95% CI: 2.12-3.65). Similar results were observed for LBW; there were no associations with SGA birth., Conclusions: ARFI hospitalization during pregnancy was associated with increased risk of PTB and LBW., Competing Interests: Declaration of Competing Interest ALN reports grants from Pfizer, grants from MedImmune/Astra Zeneca, and grants from Merck unrelated to the submitted work. All other co-authors have no potential conflicts of interest to disclose. The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the CDC or the US government. Parts of this manuscript are based on data and/or information compiled and provided by the Canadian Institute for Health Information (CIHI). However, the analyses, conclusions, opinions, and statement expressed herein are those of the authors and not necessarily those of CIHI. No endorsement by ICES, Public Health Ontario, Ontario Ministry of Health and Long-Term Care, or CIHI is intended or should be inferred., (Copyright © 2020. Published by Elsevier Ltd.)

Objectives: We sought to identify patterns of knowledge, attitudes, and behaviors (KABs) about influenza and influenza vaccination among healthcare personnel (HCP) and define characteristics associated with these patterns. Methods: We used an Internet panel survey of HCP (N = 2265) during March 27-April 17, 2018; clustered HCP by their vaccination-related KABs. Results: Four clusters were identified: Immunization Champions (61.1% of the sample) received influenza vaccine to prevent disease; Unworried Vaccinators (15.4%) received the influenza vaccine but did not believe influenza is a serious threat to themselves; Fence Sitters (8.1%) believed the vaccine is safe and worth the time and expense but is not effective; Skeptics (15.4%) did not believe the vaccine is safe or effective. Influenza vaccination coverage was 78.4% overall and higher among Immunization Champions (90.2%) and Unworried Vaccinators (87.0%) than Fence Sitters (61.6%) or Skeptics (32.2%). Conclusions: Findings suggest that based on KABs, the 3 clusters comprising 85% of HCP might be vaccinated in the future. Using messages specific to each group may improve vaccination coverage among HCP.

Background: To date, no study has examined influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza-associated hospitalizations during pregnancy., Methods: The Pregnancy Influenza Vaccine Effectiveness Network (PREVENT) consisted of public health or healthcare systems with integrated laboratory, medical, and vaccination records in Australia, Canada (Alberta and Ontario), Israel, and the United States (California, Oregon, and Washington). Sites identified pregnant women aged 18 through 50 years whose pregnancies overlapped with local influenza seasons from 2010 through 2016. Administrative data were used to identify hospitalizations with acute respiratory or febrile illness (ARFI) and clinician-ordered real-time reverse transcription polymerase chain reaction (rRT-PCR) testing for influenza viruses. Overall IVE was estimated using the test-negative design and adjusting for site, season, season timing, and high-risk medical conditions., Results: Among 19450 hospitalizations with an ARFI discharge diagnosis (across 25 site-specific study seasons), only 1030 (6%) of the pregnant women were tested for influenza viruses by rRT-PCR. Approximately half of these women had pneumonia or influenza discharge diagnoses (54%). Influenza A or B virus infections were detected in 598/1030 (58%) of the ARFI hospitalizations with influenza testing. Across sites and seasons, 13% of rRT-PCR-confirmed influenza-positive pregnant women were vaccinated compared with 22% of influenza-negative pregnant women; the adjusted overall IVE was 40% (95% confidence interval = 12%-59%) against influenza-associated hospitalization during pregnancy., Conclusion: Between 2010 and 2016, influenza vaccines offered moderate protection against laboratory-confirmed influenza-associated hospitalizations during pregnancy, which may further inform the benefits of maternal influenza vaccination programs., (Published by Oxford University Press for the Infectious Diseases Society of America 2018.)

Background: The Standards for Adult Immunization Practice (Standards), revised in 2014, emphasize that adult-care providers assess vaccination status of adult patients at every visit, recommend vaccination, administer needed vaccines or refer to a vaccinating provider, and document vaccinations administered in state/local immunization information systems (IIS). Providers report numerous systems- and provider-level barriers to vaccinating adults, such as billing, payment issues, lower prioritization of vaccines due to competing demands, and lack of information about the use and utility of IIS. Barriers to vaccination result in missed opportunities to vaccinate adults and contribute to low vaccination coverage. Clinicians' (physicians, physician assistants, nurse practitioners) and pharmacists' reported barriers to assessment, recommendation, administration, referral, and documentation, provider vaccination practices, and perceptions regarding their adult patients' attitudes toward vaccines were evaluated., Methods: Data from non-probability-based Internet panel surveys of U.S. clinicians (n = 1714) and pharmacists (n = 261) conducted in February-March 2017 were analyzed using SUDAAN. Weighted proportion of reported barriers to assessment, recommendation, administration, referral, and documentation in IIS were calculated., Results: High percentages (70.0%-97.4%) of clinicians and pharmacists reported they routinely assessed, recommended, administered, and/or referred adults for vaccination. Among those who administered vaccines, 31.6% clinicians' and 38.4% pharmacists' submitted records to IIS. Reported barriers included: (a) assessment barriers: vaccination of adults is not within their scope of practice, inadequate reimbursement for vaccinations; (b) administration barriers: lack of staff to manage/administer vaccines, absence of necessary vaccine storage and handling equipment and provisions; and (c) documentation barriers: unaware if state/city has IIS that includes adults or not sure how their electronic system would link to IIS., Conclusion: Although many clinicians and pharmacists reported implementing most of the individual components of the Standards, with the exception of IIS use, there are discrepancies in providers' reported actual practices and their beliefs/perceptions, and barriers to vaccinating adults remain., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The Advisory Committee on Immunization Practices (ACIP) recommends that all health care personnel receive an annual influenza vaccination to reduce influenza-related morbidity and mortality among health care personnel and their patients and to reduce absenteeism among health care personnel (1-4). CDC conducted an opt-in Internet panel survey of 2,265 U.S. health care personnel to estimate influenza vaccination coverage among these persons during the 2017-18 influenza season. Overall, 78.4% of health care personnel reported receiving influenza vaccination during the 2017-18 season, similar to reported coverage in the previous four influenza seasons (5). As in previous seasons, coverage was highest among personnel who were required by their employer to be vaccinated (94.8%) and lowest among those working in settings where vaccination was not required, promoted, or offered on-site (47.6%). Health care personnel working in long-term care settings, the majority of whom work as assistants or aides, have lower influenza vaccination coverage than do health care personnel working in all other health care settings, which puts the elderly in long-term settings at increased risk for severe complications for influenza. Implementing workplace strategies shown to improve vaccination coverage among health care personnel, including vaccination requirements and active promotion of on-site vaccinations at no cost, can help ensure health care personnel and patients are protected against influenza (6). CDC's long-term care web-based toolkit* provides resources, strategies, and educational materials for increasing influenza vaccination among health care personnel in long-term care settings., Competing Interests: All authors have completed and submitted the ICMJE form for disclosure of potential conflicts of interest. No potential conflicts of interest were disclosed.

Introduction: Despite the proven effectiveness of immunization in preventing morbidity and mortality, adult vaccines remain underutilized. The objective of this study was to describe clinicians' and pharmacists' self-reported implementation of the Standards for Adult Immunization Practice ("the Standards"; i.e., routine assessment, recommendation, and administration/referral for needed vaccines, and documentation of administered vaccines, including in immunization information systems)., Methods: Two Internet panel surveys (one among clinicians and one among pharmacists) were conducted during February-March 2017 and asked respondents about their practice's implementation of the Standards. T-tests assessed associations between clinician medical specialty, vaccine type, and each component of the Standards (March-August 2017)., Results: Implementation of the Standards varied substantially by vaccine and provider type. For example, >80.0% of providers, including obstetrician/gynecologists and subspecialists, assessed for and recommended influenza vaccine. However, 24.3% of obstetrician/gynecologists and 48.9% of subspecialists did not stock influenza vaccine for administration. Although zoster vaccine was recommended by >89.0% of primary care providers, <58.0% stocked the vaccine; by contrast, 91.6% of pharmacists stocked zoster vaccine. Vaccine needs assessments, recommendations, and stocking/referrals also varied by provider type for pneumococcal; tetanus, diphtheria, acellular pertussis; tetanus diphtheria; human papillomavirus; and hepatitis B vaccines., Conclusions: This report highlights gaps in access to vaccines recommended for adults across the spectrum of provider specialties. Greater implementation of the Standards by all providers could improve adult vaccination rates in the U.S. by reducing missed opportunities to recommend vaccinations and either vaccinate or refer patients to vaccine providers., (Copyright © 2018 American Journal of Preventive Medicine. All rights reserved.)

The Advisory Committee on Immunization Practices (ACIP) recommends that all health care personnel (HCP) receive an annual influenza vaccination to reduce influenza-related morbidity and mortality among HCP and their patients and to reduce absenteeism among HCP (1-4). To estimate influenza vaccination coverage among HCP in the United States during the 2016-17 influenza season, CDC conducted an opt-in Internet panel survey of 2,438 HCP. Overall, 78.6% of survey respondents reported receiving vaccination during the 2016-17 season, similar to reported coverage in the previous three influenza seasons (5). Vaccination coverage continued to be higher among HCP working in hospitals (92.3%) and lower among HCP working in ambulatory (76.1%) and long-term care (LTC) (68.0%) settings. As in previous seasons, coverage was highest among HCP who were required by their employer to be vaccinated (96.7%) and lowest among HCP working in settings where vaccination was not required, promoted, or offered on-site (45.8%). Implementing workplace strategies found to improve vaccination coverage among HCP, including vaccination requirements or active promotion of on-site vaccinations at no cost, can help ensure that HCP and patients are protected against influenza (6).

Background: The American Academy of Pediatrics recommends exclusive breastfeeding to age 6 months. Although breastfeeding rates in the United States have been increasing over time, further improvements are needed to meet Healthy People 2020 targets. Research aim: This study examined predictors of breastfeeding initiation and maintenance among a population of insured pregnant women., Methods: Participants were 1,149 pregnant women enrolled in the Pregnancy and Influenza Project in two Kaiser Permanente regions in 2010-2011. Data were collected through interviews at enrollment and 1 month and 6 months postpartum and through participants' electronic medical records., Results: Nearly all (99%) women reported initiating breastfeeding. Rates of exclusive breastfeeding were 70% and 54% at 1 month and 6 months, respectively; an additional 22% and 23% of women reported supplementing breastfeeding with formula. Of the women who supplemented, the mean ( SD) infant age at formula introduction was 53 (62) days. Of those who had stopped breastfeeding, the mean ( SD) infant age at cessation was 85 (59) days. Higher maternal education level, better maternal self-rated health, prenatal folic acid use, absence of chronic medical conditions, and infant full-term birth were significantly associated with breastfeeding maintenance., Conclusion: Although rates of breastfeeding in this population were higher than national rates, a significant number of women stopped breastfeeding or introduced formula earlier than recommended. Two to 3 months postpartum may be a critical period warranting additional encouragement or intervention by healthcare providers. Mothers' education attainment, maternal health factors, and gestational age at delivery may predict likelihood of breastfeeding maintenance.

The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all health care personnel to reduce influenza-related morbidity and mortality among both health care personnel and their patients (1-4). To estimate influenza vaccination coverage among U.S. health care personnel for the 2015-16 influenza season, CDC conducted an opt-in Internet panel survey of 2,258 health care personnel during March 28-April 14, 2016. Overall, 79.0% of survey participants reported receiving an influenza vaccination during the 2015-16 season, similar to the 77.3% coverage reported for the 2014-15 season (5). Coverage in long-term care settings increased by 5.3 percentage points compared with the previous season. Vaccination coverage continued to be higher among health care personnel working in hospitals (91.2%) and lower among health care personnel working in ambulatory (79.8%) and long-term care settings (69.2%). Coverage continued to be highest among physicians (95.6%) and lowest among assistants and aides (64.1%), and highest overall among health care personnel who were required by their employer to be vaccinated (96.5%). Among health care personnel working in settings where vaccination was neither required, promoted, nor offered onsite, vaccination coverage continued to be low (44.9%). An increased percentage of health care personnel reporting a vaccination requirement or onsite vaccination availability compared with earlier influenza seasons might have contributed to the overall increase in vaccination coverage during the past 6 influenza seasons.

The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all health care personnel (HCP) to reduce influenza-related morbidity and mortality among both HCP and their patients and to decrease absenteeism among HCP. To estimate influenza vaccination coverage among U.S. HCP for the 2014–15 influenza season, CDC conducted an opt-in Internet panel survey of 1,914 HCP during March 31–April 15, 2015. Overall, 77.3% of HCP survey participants reported receiving an influenza vaccination during the 2014–15 season, similar to the 75.2% coverage among HCP reported for the 2013–14 season. Vaccination coverage was highest among HCP working in hospitals (90.4%) and lowest among HCP working in long-term care (LTC) settings (63.9%). By occupation, coverage was highest among pharmacists (95.3%) and lowest among assistants and aides (64.4%). Influenza vaccination coverage was highest among HCP who were required by their employer to be vaccinated (96.0%). Among HCP without an employer requirement for vaccination, coverage was higher for HCP working in settings where vaccination was offered on-site at no cost for 1 day (73.6%) or multiple days (83.9%) and lowest among HCP working in settings where vaccine was neither required, promoted, nor offered on-site (44.0%). Comprehensive vaccination strategies that include making vaccine available at no cost at the workplace along with active promotion of vaccination might help increase vaccination coverage among HCP and reduce the risk for influenza to HCP and their patients.

Objectives: Although pregnant women are a high-priority group for seasonal influenza vaccination, vaccination rates in this population remain below target levels. Previous studies have identified sociodemographic predictors of vaccine choice, but relationships between preconception heath behaviors and seasonal influenza vaccination are poorly understood. This prospective cohort study followed pregnant women during the 2010-2011 influenza season to determine if certain health behaviors were associated with vaccination status., Method: Participants were pregnant women receiving prenatal care from Kaiser Permanente Northwest and Kaiser Permanente Northern California. Women were surveyed about preconception smoking, alcohol consumption, and vitamin/supplement use. Vaccination data were obtained from health plan databases and state immunization records., Results: Data from 1,204 women were included in this analysis. Most participants (1,204; 66.4%) received a seasonal influenza vaccine during the study period. Women vaccinated prior to pregnancy were more likely to use a supplement containing folic acid (80%) or vitamin D (30%) compared with women who were vaccinated during pregnancy (72% and 15%, respectively) or unvaccinated women (62% and 12%, respectively, p < .001). Women vaccinated prior to or during pregnancy were more likely (75%) to have never smoked compared with women who were not vaccinated (70%, p = .005). There were no significant differences in alcohol use or household cigarette smoke exposure by vaccination group., Conclusions: Women who engaged in specific preconception health behaviors were more likely to receive seasonal influenza vaccination. Failure to participate in these health behaviors could alert health care practitioners to patients' increased risk of remaining unvaccinated during pregnancy., (© 2014 Society for Public Health Education.)

Initiated in 1991, the Federal Healthy Start Program includes 105 community-based projects in 39 states, the District of Columbia and Puerto Rico. Healthy Start projects work collaboratively with stakeholders to ensure participants' continuity of care during pregnancy through 2 years postpartum. This evaluation of Healthy Start projects examined relationships between implementation of nine core service and system program components and improvements in birth and project outcomes. Program components and outcomes were examined using data from a 2010 Healthy Start project director (PD) survey (N = 104 projects) and 2009 performance measure data from the Maternal and Child Health Bureau Discretionary Grant Information System (N = 98 projects). We explored bivariate relationships between the nine core program components and (a) intermediate and long-term project outcomes and (b) birth outcomes. We assessed independent associations of implementation of all core program components with birth outcomes, adjusting for project characteristics and activities. In 2010, 57 projects implemented all nine core program components: 104 implemented all five core service components and 69 implemented all four core systems components. Implementation of all core program components was significantly associated with several PD-reported intermediate and long-term project outcomes, but was not associated with singleton low birth weight or infant mortality among participants' infants. This evaluation revealed a mixed set of relationships between Healthy Start projects' implementation of the core program components and achievement of project outcomes. Although the findings demonstrated a positive impact of Healthy Start projects on birth outcomes, only a few associations were statistically significant.

Background: This observational study followed a cohort of pregnant women during the 2010-2011 influenza season to determine factors associated with vaccination., Methods: Participants were 1105 pregnant women who completed a survey assessing health beliefs related to vaccination upon enrollment and were then followed to determine vaccination status by the end of the 2010-2011 influenza season. We conducted univariate and multivariate analyses to explore factors associated with vaccination status and a factor analysis of survey items to identify health beliefs associated with vaccination., Results: Sixty-three percent (n=701) of the participants were vaccinated. In the univariate analyses, multiple factors were associated with vaccination status, including maternal age, race, marital status, educational level, and gravidity. Factor analysis identified two health belief factors associated with vaccination: participant's positive views (factor 1) and negative views (factor 2) of influenza vaccination. In a multivariate logistic regression model, factor 1 was associated with increased likelihood of vaccination (adjusted odds ratio [aOR]=2.18; 95% confidence interval [CI]=1.72-2.78), whereas factor 2 was associated with decreased likelihood of vaccination (aOR=0.36; 95% CI=0.28-0.46). After controlling for the two health belief factors in multivariate analyses, demographic factors significant in univariate analyses were no longer significant. Women who received a provider recommendation were about three times more likely to be vaccinated (aOR=3.14; 95% CI=1.99-4.96)., Conclusion: Pregnant women's health beliefs about vaccination appear to be more important than demographic and maternal factors previously associated with vaccination status. Provider recommendation remains one of the most critical factors influencing vaccination during pregnancy.

The Advisory Committee on Immunization Practices recommends that all health care personnel (HCP) be vaccinated annually against influenza. Vaccination of HCP can reduce influenza-related morbidity and mortality among both HCP and their patients. To estimate influenza vaccination coverage among HCP during the 2013-14 season, CDC analyzed results of an opt-in Internet panel survey of 1,882 HCP conducted during April 1-16, 2014. Overall, 75.2% of participating HCP reported receiving an influenza vaccination during the 2013-14 season, similar to the 72.0% coverage among participating HCP reported in the 2012-13 season. Coverage was highest among HCP working in hospitals (89.6%) and lowest among HCP working in long-term care (LTC) settings (63.0%). By occupation, coverage was highest among physicians (92.2%), nurses (90.5%), nurse practitioners and physician assistants (89.6%), pharmacists (85.7%), and "other clinical personnel" (87.4%) compared with assistants and aides (57.7%) and nonclinical personnel (e.g., administrators, clerical support workers, janitors, and food service workers) (68.6%). HCP working in settings where vaccination was required had higher coverage (97.8%) compared with HCP working in settings where influenza vaccination was not required but promoted (72.4%) or settings where there was no requirement or promotion of vaccination (47.9%). Among HCP without an employer requirement for vaccination, coverage was higher for HCP working in settings where vaccination was offered on-site at no cost for 1 day (61.6%) or multiple days (80.4%) compared with HCP working in settings not offering free on-site vaccination (49.0%). Comprehensive vaccination strategies that include making vaccine available at no cost at the workplace along with active promotion of vaccination might be needed to increase vaccination coverage among HCP and minimize the risk for influenza to HCP and their patients.

Of people living with HIV in the US, ~16 % or over 150,000 individuals passed through a correctional facility in 2006. Given the enormous impact of HIV within incarcerated populations, facilitating continuity of care from jails to the community is particularly important in reducing morbidity and mortality for releasees. Grantees participating in the Enhancing Linkages to HIV Primary Care in Jail Settings Initiative developed models for identifying HIV-positive detainees during incarceration and linking them to care following release. In this sample of 1,021 HIV-infected releasees, 79 % received clinical services and 74 % received additional community services within 30 days post-release. Our analysis found several significant factors associated with linkage including: receipt of HIV or medication education in jail, having a completed discharge plan at release, staff awareness of clients' release date, and stable housing on the 30th day post-release. In addition, a subset of participants who had both jail and community viral load assessments showed a statistically significant increase in suppressed viral load. EnhanceLink data suggest that jails may be effective settings to engage individuals in care.

Over 9 million persons in the United States (US) are admitted each year to jails. HIV prevalence among detainees is higher than the general population, which creates a public health need for linking HIV-infected detainees to services during jail and after release. The EnhanceLink initiative was funded as demonstration projects in 10 communities at 20 separate jails across the US. Grantees implemented and evaluated innovative models of HIV testing in jails and linkage of HIV-infected individuals to community services post release. In this paper, we describe services delivered with the EnhanceLink initiative. During 877,119 admission events, 210,267 inmates agreed to HIV testing and 822 new diagnoses of HIV were made. The majority of persons served with transitional services were previously diagnosed before the current incarceration. Cumulatively, 9,837 HIV+ persons were offered linkage and transitional services and 8,056 (82 %) accepted the offer. EnhanceLink demonstrated the feasibility of HIV testing in jail settings and provision of linkage services to enhance continuity of HIV care post-release.

Objective: Studies examining the relationship between maternal smoking during pregnancy and the development of Attention Deficit Hyperactivity Disorder (ADHD) among offspring have yielded mixed results, with some studies suggesting a strong association and others finding no association. These studies have varied in quality of design and measures. The purpose of this study was to evaluate the association between maternal smoking during pregnancy and offspring ADHD, using detailed prospective smoking data and subsequent follow-up data from the Collaborative Perinatal Project (CPP)., Method: Maternal smoking status was collected throughout pregnancy during the original CPP study. Offspring were followed-up in early adulthood and questioned about ADHD symptoms and diagnosis. Logistic regression was used to model the association between maternal smoking during pregnancy and ADHD. Linear and logistic regression were used to examine clinical characteristics and remission rates associated with ADHD in relation to maternal smoking., Results: No association was found between maternal smoking during pregnancy and offspring ADHD. Further, no differences in age of onset, number of symptoms, or likelihood of remission were found among ADHD subjects with and without a history of maternal smoking during pregnancy., Conclusions: These findings do not support the hypothesis that maternal smoking during pregnancy is causally related to ADHD. Ongoing research should continue to strive to identify those environmental or genetic factors that may enhance the impact of maternal smoking on ADHD or that may be associated more clearly with the development and potential prevention of ADHD., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

To investigate the longitudinal course of cognitive functions in boys with persistent and remittent attention deficit/hyperactivity disorder (ADHD) from childhood into young adult years. Males (n=217) 15-31 years with and without ADHD were assessed at 3 time points over 10 years into young adulthood. Subjects were stratified into Remittent ADHD, and Persistent ADHD based on the course of ADHD. Cognitive domains included: 1) overall IQ (overall IQ, block design IQ, vocabulary IQ); 2) achievement scores in reading and math and measures of executive function (Wechsler arithmetic, digit span, digit symbol, Rey-Osterrieth, Wisconsin Card Sorting Test, and the Stroop Test). Cognitive outcomes were modeled as a function of group (Controls, Remittent ADHD, and Persistent ADHD), age, group by age interaction, and any demographic confounders using linear growth-curve models. There were no significant interaction effects of group by time. Main group effects indicated that persistent and remittent ADHD groups both had significantly lower scores on all cognitive outcomes compared with controls, and these did not differ between the ADHD subgroups Psychometrically defined cognitive deficits are relatively stable into young adult years and appear to be independent of the course of ADHD. More work is needed to help define the implications of these deficits in individuals with a remitting course of ADHD.

Objective: The main aim of this study was to evaluate the association between attention-deficit/hyperactivity disorder (ADHD) and major depression (MD) in adolescent and young adult females., Method: Subjects were females with (n = 140) and without (n = 122) ADHD ascertained from pediatric and psychiatric settings. Subjects were followed prospectively for 5 years into adolescence and young adulthood and reassessed in multiple nonoverlapping domains including psychiatric, cognitive, interpersonal, family, and educational functioning., Results: Females with ADHD had a 2.5 times higher risk for MD at adolescent follow-up compared with control females, adjusting for psychiatric comorbidity. MD in females with ADHD was associated with an earlier age at onset, greater than twice the duration, more severe depression-associated impairment, a higher rate of suicidality, and a greater likelihood of requiring psychiatric hospitalization than MD in control girls. Parental MD and proband mania were significant predictors of MD among females with ADHD, independently of other predictors., Conclusions: MD emerging in the context of ADHD in females is an impairing and severe comorbidity worthy of further clinical and scientific considerations.

Objective: To evaluate the association between attention-deficit/hyperactivity disorder (ADHD) and eating disorders in a large adolescent population of girls with and without ADHD., Method: We estimated the incidence of lifetime eating disorders (either anorexia or bulimia nervosa) using Cox proportional hazard survival models. Comparisons between ADHD girls with and without eating disorders were then made on measures of comorbidity, course of ADHD, and growth and puberty., Results: ADHD girls were 3.6 times more likely to meet criteria for an eating disorder throughout the follow-up period compared to control females. Girls with eating disorders had significantly higher rates of major depression, anxiety disorders, and disruptive behavior disorder compared to ADHD girls without eating disorders. Girls with ADHD and eating disorders had a significantly earlier mean age at menarche than other ADHD girls. No other differences in correlates of ADHD were detected between ADHD girls with and without eating disorders., Conclusions: ADHD significantly increases the risk of eating disorders. The presence of an eating disorder in girls with ADHD heightens the risk of additional morbidity and dysfunction.

Objective: We evaluated correlates of the diagnosis of ADHD in youth by informant source., Method: Ninety-four pairs of mother reports and youth self-reports on ADHD were independently assessed, using diagnostic interviews from a large study of youth of both genders with and without ADHD. Comparisons were made on measures of interpersonal, school, and family functioning; treatment history; and parental psychopathology by informant source., Results: With the exception of higher rates of ADHD-associated impairment and higher frequency of treatment for ADHD in the combined youth-mother group. There were no other differences in any other clinical or familial correlates by informant source; both informant groups had higher levels of impairment in multiple nonoverlapping measures of dysfunction than controls. Males were overrepresented among the mother-only group., Conclusion: Maternal reports of ADHD result in a meaningful diagnosis of ADHD with high levels of impairment, regardless of endorsement by the affected youth.

A focus of current diabetes research is the development of insulinomimetic compounds for oral treatment of diabetes and its associated cardiac complications. Screening compounds for their potential insulinomimetic effects usually involves the use of radioactive isotopes. The focus of this study was to investigate a nonradioactive fluorescent compound for its use in screening insulinomimetic compounds. The indicator 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG) has been used by some workers to measure glucose uptake in Escherichia coli and Candida albicans. We propose that 2-NBDG will also be a suitable indicator for mammalian cell lines, in particular rat cardiomyocytes. We found that the indicator could give a reliable reproducible standard curve following appropriate dilution and is taken up by isolated cardiomyocytes. The insulinomimetic compounds vanadyl sulfate and sodium molybdate showed rates of glucose uptake similar to that of insulin. Furthermore, the rate of uptake measured for insulin using this technique (0.04 +/- 0.003 nmol x min(-1) x 10(6) cells(-1) is comparable with previous literature using 2-deoxyglucose uptake measurements on isolated myocytes (0.040 nmol x min(-1) x 10(6) cells(-1), demonstrating the validity of this fluorescent compound for glucose uptake studies.