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Measles affects those of lower socioeconomic status disproportionately. This study evaluated the impact of measles vaccination on antibody titers 3 months after vaccination across different socioeconomic groups, with a focus on caste. In total, 169 infants in Chandigarh, India, had serum samples collected immediately prior to vaccination at 9 months of age and 3 months later. Overall, 126 infants (76%) were seropositive (antibody titers > 12 mIU/mL), 26 (16%) were borderline (8–12 mIU/mL), and 14 (8%) were seronegative (< 8 mIU/mL). Seropositivity (versus borderline/seronegative infants) was 0.78 times as high among individuals from the historically marginalized scheduled castes/scheduled tribes compared with the others caste grouping (95% CI, 0.62–0.98). Antibody response was not tied to anthropometric measures but was attenuated among scheduled castes/scheduled tribes with higher incomes. This study provides observational evidence that social structures can be associated with individual immune responses.

It is important to distinguish between apprehensions that lead to vaccine rejection and those that do not. In this study, we (1) identifed latent classes of individuals by vaccination attitudes, and (2) compared classes of individuals by sociodemographic characteristics COVID-19 vaccination, and risk reduction behaviors. The COVID-19 Coping Study is a longitudinal cohort of US adults aged ≥ 55 years (n = 2358). We categorized individuals into three classes based on the adult Vaccine Hesitancy Scale using latent class analysis (LCA). The associations between class membership and sociodemographic characteristics, COVID-19 vaccination, and other behaviors were assessed using chi-square tests. In total, 88.9% were Vaccine Acceptors, 8.6% were Vaccine Ambivalent, and 2.5% Vaccine Rejectors. At the end, 90.7% of Acceptors, 62.4% of the Ambivalent, and 30.7% of the Rejectors had been vaccinated. The Ambivalent were more likely to be Black or Hispanic, and adopted social distancing and mask wearing behaviors intermediate to that of the Acceptors and Rejectors. Targeting the Vaccine Ambivalent may be an efficient way of increasing vaccination coverage. Controlling the spread of disease during a pandemic requires tailoring vaccine messaging to their concerns, e.g., through working with trusted community leaders, while promoting other risk reduction behaviors. Supplementary Information The online version contains supplementary material available at 10.1007/s10900-022-01064-w.

Measles continues to result in focal outbreaks in India, despite over three decades of universal infant vaccination. The aims of this study were to examine measles immunity in the population of Chandigarh, India, and to compare immunity by vaccination vs. natural infection. In a cross-sectional study of individuals 1-60 years selected from 30 communities within Chandigarh during 2017-2018, measles immunity was assessed using serological surveys. Seropositivity was compared across demographic groups, and by prior history of vaccination and natural history of infection. Among those 1-20 years old, measles seropositivity, and histories of measles vaccination or prior measles diagnosis were separately assessed as outcomes in logistic regression models, with demographic factors as independent variables. Among 1690 participants, 94% were seropositive, and 6% had borderline or negative antibody levels. Of those positive, 30% had prior vaccination, 16% had a history of natural infection, and 54% had an unknown history. Over 50% of individuals among those20 years old, had unknown history of immunity. In the multivariable regression models, vaccination was more common in younger ages (P .0001), and in males compared to females (P = .0220), and in those with more education (P .0001). The majority of the population was seropositive, and seropositivity increased with age. Older age groups were more likely to be protected because of previous natural infection, whereas younger age groups were protected by vaccination. There was inequity in vaccination coverage by gender, and maternal education status.

Clinicians in intensive care units (ICUs) have been prioritized for COVID-19 vaccination. We aim to understand the reasons behind vaccination refusal, and assess preferences for COVID-19 vaccines among Chinese ICU clinicians.ICU clinicians throughout China's mainland were contacted to participate in an online survey. We compared concerns with vaccination status, and through a discrete choice experiment (DCE) assessed preferences for vaccines in terms of effectiveness, risk of adverse reactions, duration of immunity, and whether coworkers have been vaccinated.Among 11,951 ICU respondents from 252 prefecture-level regions, vaccination coverage was 75.4%, with an additional 9.2% not vaccinated but intending to, and 16.1% not vaccinated and not intending to. ICU clinicians not intending to be vaccinated significantly expressed more concerns about the speed of vaccine development (30.1%) and adverse reactions (65.9%). In the DCE, the only significant difference in preferences of a COVID-19 vaccine was for safety, with those not intending to have a stronger preference for a vaccine with fewer adverse reactions (OR = 4.49), compared to those already vaccinated (OR = 2.90) or those intending to vaccinate (OR = 3.46).Increasing vaccination coverage among Chinese ICU clinicians will require strong norms surrounding vaccination and transparency about safety information.

Background Nepal has made substantial improvements in childhood immunization uptake. However, vaccination levels are still below the country-specific Sustainable Development Goal target of 94.8% coverage by 2025 for children aged 12–23 months who received all immunizations recommended in the national immunization schedule by their first birthday. A better understanding of the predictors of full immunization can inform successful programmatic interventions to improve coverage while also guiding resource allocation to ensure all children are fully vaccinated. This study estimates childhood immunization coverage in Nepal and characterizes the association between immunization status and various sociodemographic predictors. Methods Data from the 2016 Nepal Demographic and Health Survey were used to examine the immunization status of children aged 12–23 months. Immunization status was categorized as fully immunized (receiving all recommended doses), under-immunized (receiving at least one, but not all, recommended doses), and un-immunized (not receiving any doses of any vaccine). Associations between full and under-immunization and potential sociodemographic predictors were assessed using logistic regression. Results Among 976 children, 78.2% were fully immunized, 21% were under-immunized, and 0.8% were un-immunized. Retention of an immunization card was significantly associated with full immunization status. Mothers who had completed a formal education above secondary school and mothers who were working at time of interview had increased odds of full immunization. Birthing in an institutional setting was also associated with higher odds of full immunization. Conclusions Overall, immunization coverage in Nepal is relatively high, although it varies by dose and sociodemographic factors. Almost 25% of Nepalese children were not fully immunized, leaving them at increased risk for vaccine-preventable disease related morbidity and mortality. Nepal must continue focused efforts to reach every child and minimize the equity gap; programs may focus on advocating for the use of immunization cards, education and empowerment for girls, and delivery in institutional settings.

This study examined whether future COVID-19 vaccine acceptance differed based on an experimental manipulation of the vaccine safety and effectiveness profile. Data come from the Detroit Metro Area Community Study, a population-based study conducted July 15–20, 2020. Participants were asked whether they would get a new COVID-19 vaccine after being randomly assigned information about the vaccine’s effectiveness (50% or 95%) and chance of fever (5% or 20%). Among 1,117 Detroiters, 51.3% would accept a COVID-19 vaccine that is 50% effective and 77.1% would accept a vaccine that is 95% effective. Women and adults ≥65 were more accepting of a vaccine; Black Detroiters were less accepting. Believing vaccines to be important, effective, and safe was associated with higher acceptance. Uptake of a COVID-19 may be limited, depending on perceived vaccine effectiveness and general attitudes toward vaccines. Public health approaches to modifying these attitudes will be especially important in the Black community.

An outbreak of SARS-CoV-2 has led to a global pandemic affecting virtually every country. As of August 31, 2020, globally, there have been approximately 25,500,000 confirmed cases and 850,000 deaths; in the United States (50 states plus District of Columbia), there have been more than 6,000,000 confirmed cases and 183,000 deaths. We propose a Bayesian mixture model to predict and monitor COVID-19 mortality across the United States. The model captures skewed unimodal (prolonged recovery) or multimodal (multiple surges) curves. The results show that across all states, the first peak dates of mortality varied between April 4, 2020 for Alaska and June 18, 2020 for Arkansas. As of August 31, 2020, 31 states had a clear bimodal curve showing a strong second surge. The peak date for a second surge ranged from July 1, 2020 for Virginia to September 12, 2020 for Hawaii. The first peak for the United States occurred about April 16, 2020—dominated by New York and New Jersey—and a second peak on August 6, 2020—dominated by California, Texas, and Florida. Reliable models for predicting the COVID-19 pandemic are essential to informing resource allocation and intervention strategies. A Bayesian mixture model was able to more accurately predict the shape of the mortality curves across the United States than other models, including the timing of multiple peaks. However, given the dynamic nature of the pandemic, it is important that the results be updated regularly to identify and better monitor future waves, and characterize the epidemiology of the pandemic.

Introduction Although vaccination coverage is high in Kenya relative to other African nations, undervaccinated children remain, making it important to identify characteristics of these children and their caregivers. Potentially relevant but understudied factors are women's empowerment and early marriage. Women who marry older and have more autonomous decision-making authority may be better able to ensure their children receive health services, including immunizations. This analysis examines the relationship between early marriage and multiple dimensions of women's empowerment and child vaccination status in Kenya and explores whether these relationships are modified by wealth. Methods Data were from the 2014 Kenya Demographic and Health Survey. The analysis was completed in 2020 using updated data made available to researchers in 2019. Logistic regressions assessed relationships among early marriage, 3 dimensions of women's empowerment (enabling conditions, intrinsic agency, and instrumental agency), and child vaccination. Analyses were stratified by wealth to explore potential effect modification. Results For women in the middle wealth tertile, the odds of having a fully vaccinated child were 3.45 (95% CI=1.51, 7.91) times higher for those with higher versus lower empowerment. Further, among the wealthiest women, those with middle empowerment were 5.99 (95% CI=2.06, 17.40) times more likely to have a fully vaccinated child than women with lower empowerment. Conclusions Results suggest a threshold effect of wealth's role in the relationship between empowerment and vaccination. Enabling conditions may not influence immunization among the poorest women but exert a stronger positive influence on childhood vaccination among wealthier women. Supplement information This article is part of a supplement entitled Global Vaccination Equity, which is sponsored by the Global Institute for Vaccine Equity at the University of Michigan School of Public Health.

It is not clear what kind of preferences parents in China would have for vaccines that could be added to a future immunization schedule. This study’s aim was to assess Chinese parents’ preferences for attributes of vaccines. We surveyed parents of young infants ≤3 months of age at immunization clinics in Shanghai, China, in 2017. We used a discrete choice experiment (DCE) to present parents with choices between two hypothetical profiles of vaccines which were described using the following attributes: cost, risk of side effect, location of vaccine manufacturer, vaccine testing, vaccine effectiveness, severity of disease, disease prevalence. A logistic regression output estimates of preference utilities. In total, 599 caregivers completed the DCE. Parents expressed lower preference for vaccines with a 30% chance of fever as an adverse event vs a 10% chance (OR: 0.53, 95% CI: 0.44, 0.64), for vaccines only 85% effective vs those 95% effective (OR: 0.55, 95% CI: 0.48, 0.62), and for imported vaccines (OR: 0.74, 95% CI: 0.60, 0.92) and those not tested in Chinese children (OR: 0.45, 95% CI: 0.37, 0.53) compared to domestic vaccines. More affluent groups preferred more expensive vaccines whereas less affluent groups did not express cost-based preferences. Promotion of vaccines in China should focus on parents’ stated preferences, which include past testing done in Chinese children – which is, in fact, required of all licensed vaccines in China. Information about these trials could emphasize low risk of adverse events and high effectiveness.

Compared to many other countries, China offers fewer pediatric vaccines. Future attempts to add mandatory vaccines may run counter to parents’ preferences for shot-limiting. The aim of this study was to assess Chinese parents’ preferences and willingness-to-pay (WTP) for programmatic attributes of vaccination services. Parents of young infants ≤3 months of age presenting at immunization clinics in Shanghai, China, in 2017 completed a discrete choice experiment (DCE) on vaccination program attributes: waiting time at the clinic, number of shots before 7 months, number of injections per visit, cost per visit, and location of the shot. We estimated preference utilities and WTP using logistic regression. In total, 590 completed the DCE. Caregivers expressed greater utility for less waiting time, fewer office visits, lower cost of vaccines, and fewer injections co-administered. Over the course of their child’s first 6 months, parents were willing to pay 113 RMB ($17) to avoid an additional 10 minutes of waiting at each appointment (95% confidence interval [CI]: 213, 929), 474 RMB ($70) to avoid an additional office visit (95% CI: 241, 707), and 703 RMB ($104) to avoid an additional injection at each appointment (95% CI: 337, 1068). As China expands its list of publicly funded vaccines, public health officials will have to counter Chinese parents’ strong preferences for limiting the total number of office visits and the number of injections administered at each visit, potentially through the use of combination vaccines.

In China, HPV vaccines are not mandatory and have low uptake. In light of the U.S.’s experience in rolling out the vaccine with an initial focus primarily on HPV as a sexually transmitted infection but transitioning later to cancer messaging, we used a multifactorial experiment to create several different messages about the HPV vaccine across age, communicability, and cancer domains. In this study, we assess the effect of the different messages on willingness to accept an HPV vaccine, and characterize how parental sociodemographics and the age/gender of a child also impact willingness to obtain an HPV vaccine. In total, 1,021 parents of children aged less than 18 years old in Shanghai, China were randomized to receive a message about cancer (HPV causes cervical cancers vs cancers in general), infectiousness (HPV is sexually transmitted, or is an infectious disease in general, or not mentioned), and recommended age of vaccination (before middle school, before college/work, or not mentioned). Parents were asked if they would vaccinate a hypothetical son or daughter of different ages 6, 12, or 18 years old). In a multivariable logistic regression model adjusting for parental sociodemographic characteristics, parents were more likely to want to vaccinate a daughter vs a son, and an older vs younger child. Messaging had some effect in certain circumstances: parents were more likely to accept a vaccine for a 6-year-old son if given information that it protected against cancers in general. Providing information about a sexually transmitted infection led to higher willingness to vaccinate a son 6 years old and a daughter 6 or 12 years old. This study showed messaging had some limited impact on willingness to vaccinate against HPV, but more research is needed on how to increase uptake of the HPV vaccine when it is not publicly funded.

Objective Mobile phones are used in research studies, to enroll and follow-up participants, collect data, and implement mHealth initiatives. We conducted a longitudinal study in a birth cohort, where infants were required to make four scheduled visits by 12 months of age. Families of those failing to attend scheduled follow-up visits, were contacted telephonically to ascertain the reasons, which were categorized as: not interested to continue participating, migrated, phone disconnected due to telecom change, or other reason. Results A total of 413 mother-infant dyads were enrolled. The overall attrition was 56%, with majority occurring at the first follow-up visit. This temporally coincided with a telecom service provider announcing strong incentives to switch providers. Attrition monotonically decreased at subsequent visits. The reasons were: moved away (13%), no longer interested (8%), phone disconnected (7%), and multiple other reasons (28%), the majority of whom had unreachable phones. Those who remained in the study and those lost to follow-up were similar on most demographic variables. Among common reasons for attrition in cohort studies, we experienced a new dimension introduced by telecom changes. These findings underscore the need to consider unexpected reasons for attrition in longitudinal studies, and design more robust methods to follow-up participants.

Introduction:measures of vaccine timing require data on vaccination dates, which may be unavailable. This study compares estimates of vaccine coverage and timing; and compares regression techniques that model these measures in the presence of incomplete data. Methods:this cross-sectional study used the 2016 Ethiopian Demographic and Health Survey (DHS), and a 2016 survey from Worabe, Ethiopia. Three measures of vaccine uptake were calculated: coverage (regardless of timing), timeliness (within 1 week of recommended administration), and delay (the number of days between the recommended and actual date of vaccination). Vaccine coverage and timeliness were modeled with logistic regressions. After excluding those without dates, vaccine delay was estimated using linear regression or survival analysis. Vaccine delay was also estimated using accelerated failure time (AFT) models. Results:the DHS survey included 3819 children aged 12-60 months and the Worabe survey included 484 children aged 12-23 months. In the Worabe survey, vaccine coverage for pentavalent vaccine dose 3 was 87.4%, with 8.6% receiving it within 1 week, and 71.7% within 4 weeks; the median delay was 19 days. Predictors of outcomes were similar in both the Worabe survey and Ethiopian DHS, with the largest numbers of significant associations seen in models with vaccine coverage or delays (with AFT models) as the outcomes. Conclusion:estimates of coverage may miss a substantial proportion of infants who have delayed vaccination. accelerated failure time (AFT) models are useful to estimate vaccine delay because they include information from all respondents (those with full and partial data on vaccination dates) and are agnostic about an age limit for timely vaccination.

Background A hepatitis E (HepE) vaccine was developed and released in China in 2011. Uptake is currently very limited. The aims of this study were to characterize what public health professionals thought about promoting the HepE vaccine in Shanghai, China, and to develop realistic goals for the HepE vaccine based on this information. Methods Public health professionals from Shanghai and other jurisdictions of China were contacted to participate in in-depth qualitative interviews between October 2017 and August 2018. Participants were asked about their perception of the HepE vaccine roll-out. Codes were initially based on the structure of the questionnaire. Subsequently, similar ideas were further developed into themes based on what was present in the transcript data. Results Thirty-five individuals participated. Major topics of discussion included (1) clarifying the roles and responsibilities of private and public institutions in promoting and marketing the HepE vaccine, (2) identifying what methods of promotion were most efficient, and, (3) endeavoring to formulate a reasonable and realistic goal, if any, for HepE prevention and control in China. Participants emphasized that public sector sources can be trusted sources of information (although the private vaccination company can also be useful in disseminating information) and social media such as WeChat can be good ways to disseminate articles (although netizens may be worried about the spread of fake news). Vaccine promotion is restrained given limited levels of knowledge in the government, hospitals, and public health vaccination centers. Conclusion Successful promotion and use of this vaccine in China, even in limited settings (for instance, certain workplaces, or certain groups) could provide additional information on long-term safety and could promote its adoption in other regions of the world where HepE has high morbidity among pregnant women and other populations.

Background: Traditional measurements of vaccine coverage at specific ages can mask poor vaccine timeliness. However, optimal measurement of timing is unclear due to variations in countries’ recommended vaccination schedules and lack of a commonly accepted standard for “timeliness”. We conducted a systematic review of literature on vaccine timeliness and delay in low- and middle-income countries from 2007 to 2017. Methods: A search of articles published between January 1 2007 and December 31 2017, was performed in PubMed, EBSCOhost, and Embase. Results: 67 papers were included, of which 83% used a categorical measure of delay and 41% evaluated continuous delay. The most common age at assessment was 1 month, with earlier age benchmarks typically used with birth doses. Conclusions: Categorical definitions of vaccination timing vary widely, with benchmarks of delay varying from days to weeks to months. Use of a continuous measure of vaccine delay may be more informative and comparable.

Introduction Rates of full childhood immunization in Ethiopia are well below the WHO global goal of 90% coverage by 2020. This study explores associations between sociodemographic characteristics and healthcare services utilization with experiences of not receiving a vaccine in Ethiopia. Methods This analysis uses data from Ethiopia’s 2012 Expanded Program on Immunization Coverage Survey. The relationships between explanatory variables, including sociodemographic and healthcare utilization factors, and various reasons a child was not vaccinated were assessed with Rao-Scott chi-square tests. Multivariable logistic regression analyses examined significant predictors of these experiences. Results The sample includes the caregivers of 2,722 children. Experiences of not receiving a vaccine were characterized overall and by type of experience: whether a caregiver ever refused vaccination for their child (2.9%), ever decided to not take their child to a health center for vaccination (3.6%), and ever went to a health facility for vaccination but child was not vaccinated (12.0%). Region of residence, possession of a vaccination card, and the setting of the child’s last routine vaccination were predictors of not receiving a vaccine. Caregivers reported negative perceptions of vaccines were among their reasons for refusing a vaccine or declining to take their child to a health facility for vaccination. Conclusion Prior experiences with health facilities, such as where a child received their last routine vaccine, play a key role in future vaccination. Vaccine receipt at an outreach event is associated with not bringing a child to a health facility for vaccination, which may indicate an unwillingness to visit or difficulty accessing health centers. Further, negative perceptions of vaccines may result in vaccine refusal or delay. Findings of this study provide public health officials with a better understanding of factors related to vaccination experiences and can inform development of interventions that will improve childhood vaccination rates in Ethiopia.

Morbidity from vaccine-preventable diseases is high in India, but precise estimates of vaccination timeliness are difficult to compute because many children lack records of vaccination dates. This study assessed vaccination timeliness after accounting for right and left censoring of data. This cross-sectional study used the 2012–2013 District Level Household and Facility Survey in India. The outcome was vaccination timeliness for 9 vaccine doses: 1 dose Bacillus Calmette-Guerin (BCG), 4 doses oral polio vaccine, 3 doses diphtheria-pertussis-tetanus vaccine (DPT), and 1 dose measles-containing vaccine. Age-specific probabilities of vaccination were calculated using Turnbull estimators: children not yet vaccinated were right censored, and children vaccinated but without a recorded date were left censored. Data from 108,783 children under 5 years were available. For children 25–60 months, maternal recall was a more common source of information than a vaccination record with dates. At one month past the recommended vaccination age, estimated coverage ranged from 35% for DPT-3 to 55% for BCG. Accounting for censored data improved vaccination timeliness measures, and demonstrated little increase in vaccination coverage after age one. Efforts to reduce morbidity from vaccine-preventable diseases in India should focus on eliminating missed opportunities for vaccination and instituting special vaccination programs for older children.

Timely receipt of recommended vaccines is a proven strategy to reduce preventable under-five deaths. Kenya has experienced impressive declines in child mortality from 111 to 43 deaths per 1000 live births between 1980 and 2019. However, considerable inequities in timely vaccination remain, which unnecessarily increases risk for serious illness and death. Maternal migration is a potentially important driver of timeliness inequities, as the social and financial stressors of moving to a new community may require a woman to delay her child's immunizations. This analysis examined how maternal migration to informal urban settlements in Nairobi, Kenya influenced childhood vaccination timeliness.Data came from the Nairobi Urban Health and Demographic Surveillance System, 2002-2018. Migration exposures were migrant status (migrant, non-migrant), migrant origin (rural, urban), and migrant type (first-time, circular [previously resided in settlement]). Age at vaccine receipt (vaccination timeliness) was calculated for all basic vaccinations. Accelerated failure time models were used to investigate relationships between migration exposures and vaccination timeliness. Confounding was addressed using propensity score weighting.Over one-third of the children of both migrants and non-migrants received at least one dose late or not at all. Unweighted models showed the children of migrants had shorter time to OPV1 and DPT1 vaccine receipt compared to the children of non-migrants. After accounting for confounding only differences in timeliness for DPT1 remained, with the children of migrants receiving DPT1 significantly earlier than the children of non-migrants. Timeliness was comparable among migrants with rural and urban origins and among first-time and circular migrants.Although a substantial proportion of children in Nairobi's informal urban settlements do not receive timely vaccination, this analysis found limited evidence that maternal migration and migration characteristics were associated with delays for most doses. Future research should seek to elucidate potential drivers of low vaccination timeliness in Kenya.

New vaccine introduction accompanied by social mobilization activities could contribute to improved routine immunization timeliness. This study assesses the impact of Kenya’s introduction of pneumococcal conjugate vaccine (PCV) on the timeliness of routine childhood vaccination in two informal, urban settlements in Nairobi. Data collected from 2007 to 2015 as part of a demographic surveillance system were used to estimate annual vaccination delays of ≥ 4 weeks among children aged 12–23 months in the period before and after the introduction of PCV in Kenya. Binomial segmented regression models using generalized estimating equations examined the association between vaccine introduction and timeliness of routine immunization. Over half of all children vaccinated in the two urban areas received one or more doses ≥ 4 weeks after the recommended age. The timeliness of routine immunization showed slight improvements or nonsignificant changes during the years following PCV introduction compared with the preceding years (adjusted prevalence ratio [aPR]: 0.67, 95% CI: 0.45–0.99 for Bacille Calmette-Guerin receipt; aPR: 0.59, 95% CI: 0.41–0.83 for third dose Pentavalent receipt; aPR: 1.19, 95% CI: 0.99–1.42 for measles). However, as of 2015, delayed vaccination remained prevalent in children, particularly among the poorest residing in the settlements. Many sub-Saharan African countries have introduced new life-saving vaccines into their routine childhood immunization schedule. Additional evidence regarding the positive or neutral influence of new vaccine introduction on the performance of delivery systems provides further justification to sustain the inclusion of these more costly vaccines in the immunization schedule.

Background: Health care workers in intensive care units (ICU) have been prioritized for COVID-19 vaccination. In a nationwide vaccination campaign since March in China, better understanding of concerns and preferences of COVID-19 vaccines remain crucial for improving vaccination uptake. Methods: ICU clinicians throughout China’s mainland were contacted to participate in an online survey during March 24-April 10, 2021. We compared concerns by vaccination outcome, and through a discrete choice experiment (DCE) assessed preferences for vaccines in terms of effectiveness (95% vs 80%), risk of adverse reactions (5% vs 10%), duration of immunity (6 vs 12 months), and whether or not coworkers have been vaccinated. Findings: Among 11,951 ICU respondents from 252 prefecture-level cities, vaccination coverage of COVID-19 vaccines was 75·4%, with an additional 9·2% not vaccinated but planning to, and 16·1% not vaccinated and not intending to. Among women not pregnant, vaccination coverage was 82·6%, with lower coverage in those pregnant (11·4%) or breastfeeding (19·7%). ICU clinicians not intending to be vaccinated significantly expressed more concerns about the speed of vaccine development (30·1%) and adverse reactions (65·9%), compared to those already vaccinated. In the DCE, by COVID-19 vaccination status, the only significant difference in preferences of a COVID-19 vaccine was for safety, with those not vaccinated having a stronger preference for a vaccine with fewer adverse reactions (OR=4·49) compared to those already vaccinated (OR=2·90) or those intending to vaccinate (OR=3·46) (P

Objectives Kenya has substantially improved child mortality between 1990 and 2019, with under-5 mortality decreasing from 104 to 43 deaths per 1000 live births. However, only two-thirds of Kenyan children receive all recommended vaccines by 1 year, making it essential to identify undervaccinated subpopulations. Internal migrants are a potentially vulnerable group at risk of decreased access to healthcare. This analysis explored how maternal migration within Kenya influences childhood vaccination. Methods Data were from the 2014 Kenya Demographic and Health Survey, a nationally representative cross-sectional survey. Logistic regressions assessed relationships between maternal migration and full and up-to-date child vaccination using inverse probability of treatment weighting. Two exposure variables were examined: migration status and stream (e.g. rural-urban). Multiple imputation was used to impute up-to-date status for children without vaccination cards to reduce selection bias. Results After accounting for selection and confounding biases, all relationships between migration status and migration stream and full and up-to-date vaccination became statistically insignificant. Conclusions Null findings indicate that, in Kenya, characteristics enabling migration, rather than the process of migration itself, drive differential vaccination behavior between migrants and non-migrants. This finding is an important deviation from previous literature, which did not rigorously address important biases.

ObjectiveTo characterise studies which have used Demographic and Health Survey (DHS) datasets to evaluate vaccination status.DesignScoping review.Data sourcesElectronic databases including PubMed, EBSCOhost and POPLINE, from 2005 to 2018.Study selectionAll English studies with vaccination status as the outcome and the use of DHS data.Data extractionStudies were selected using a predetermined list of eligibility criteria and data were extracted independently by two authors. Data related to the study population, the outcome of interest (vaccination) and commonly seen predictors were extracted.ResultsA total of 125 articles were identified for inclusion in the review. The number of countries covered by individual studies varied widely (1–86), with the most published papers using data from India, Nigeria, Pakistan and Ethiopia. Many different definitions of full vaccination were used although the majority used a traditional schedule recommended in the WHO’s Expanded Programme on Immunisation. We found studies analysed a wide variety of predictors, but the most common were maternal education, wealth, urbanicity and child’s sex. Most commonly reported predictors had consistent relationships with the vaccination outcome, outside of sibling composition.ConclusionsResearchers make frequent use of the DHS dataset to describe vaccination patterns within one or more countries. A clearer idea of past use of DHS can inform the development of more rigorous studies in the future. Researchers should carefully consider whether a variable needs to be included in the multivariable model, or if there are mediating relationships across predictor variables.

The United States experienced historically high numbers of measles cases in 2019, despite achieving national measles vaccination rates above the World Health Organization recommendation of 95% coverage with two doses. Since the COVID-19 pandemic began, resulting in suspension of many clinical preventive services, pediatric vaccination rates in the United States have fallen precipitously, dramatically increasing risk of measles resurgence. Previous research has shown that measles outbreaks in high-coverage contexts are driven by spatial clustering of nonvaccination, which decreases local immunity below the herd immunity threshold. However, little is known about how to best conduct surveillance and target interventions to detect and address these high-risk areas, and most vaccination data are reported at the state-level-a resolution too coarse to detect community-level clustering of nonvaccination characteristic of recent outbreaks. In this paper, we perform a series of computational experiments to assess the impact of clustered nonvaccination on outbreak potential and magnitude of bias in predicting disease risk posed by measuring vaccination rates at coarse spatial scales. We find that, when nonvaccination is locally clustered, reporting aggregate data at the state- or county-level can result in substantial underestimates of outbreak risk. The COVID-19 pandemic has shone a bright light on the weaknesses in US infectious disease surveillance and a broader gap in our understanding of how to best use detailed spatial data to interrupt and control infectious disease transmission. Our research clearly outlines that finer-scale vaccination data should be collected to prevent a return to endemic measles transmission in the United States.

INTRODUCTION Improving the timeliness and completion of vaccination is the key to reducing under-5 childhood mortality. This study examines the prevalence of delayed vaccination for doses administered at birth and age 6 weeks, 10 weeks, 14 weeks, and 9 months and its association with undervaccination among infants in Sub-Saharan Africa. METHODS Pooling data across 33 Sub-Saharan Africa countries, vaccination timing and series completion were assessed for children aged 12-35 months who were included in the immunization module of the Demographic and Health Surveys conducted between 2010 and 2019. Survey design-adjusted logistic regression modeled the likelihood of not fully completing the basic immunization schedule associated with dose-specific delays in vaccination. Data were obtained and analyzed in May 2020. RESULTS Among children with complete date records (n=70,006), the proportion of children vaccinated with delays by ≥1 month was high: 25.9% for Bacille Calmette-Guerin (at birth); 49.1% for the third dose of pentavalent combination vaccine (at 14 weeks); and 63.9% for the first dose of measles vaccines (at 9 months). Late vaccination was more common for children born to mothers with lower levels of educational attainment (p

Michigan experienced a significant measles outbreak in 2019 amidst rising rates of nonmedical vaccine exemptions (NMEs) and low vaccination coverage compared with the rest of the United States. There is a critical need to better understand the landscape of nonvaccination in Michigan to assess the risk of vaccine-preventable disease outbreaks in the state, yet there is no agreed-upon best practice for characterizing spatial clustering of nonvaccination, and numerous clustering metrics are available in the statistical, geographical, and epidemiologic literature. We used school-level data to characterize the spatiotemporal landscape of vaccine exemptions in Michigan for the period 2008–2018 using Moran’s I, the isolation index, the modified aggregation index, and the Theil index at 4 spatial scales. We also used nonvaccination thresholds of 5%, 10%, and 20% to assess the bias incurred when aggregating vaccination data. We found that aggregating school-level data to levels commonly used for public reporting can lead to large biases in identifying the number and location of at-risk students and that different clustering metrics yielded variable interpretations of the nonvaccination landscape in Michigan. This study shows the importance of choosing clustering metrics with their mechanistic interpretations in mind, be it large- or fine-scale heterogeneity or between- and within-group contributions to spatial variation.

Introduction Rapidly urbanizing communities in middle-income countries could be sources of vaccine hesitancy, and may create hot spots of low vaccination coverage. This study characterizes vaccine hesitancy in Shanghai and identifies disparities in vaccine safety and efficacy concerns by residency status—a marker for recent migration into the city. Methods Parents of children aged ≤18 years from immunization clinics in Shanghai were enrolled in summer 2019, with the data analyzed during winter 2019–2020. The paper questionnaire used the Parental Attitudes towards Childhood Vaccines scale, which included questions about vaccine safety and efficacy concerns. The primary independent variable was residency—whether an individual was a Shanghai local or a recent migrant (i.e., non-local). Linear regression models assessed the relationship between residency and vaccine safety and efficacy concerns. Results Among 1,021 participants, 65.4% had local residency, and the remainder were urban non-locals (13.1%) or rural non-locals (21.5%). A majority of parents expressed concerns about vaccine side effects (73.8%), vaccine safety (63.9%), and vaccine effectiveness (52.4%). Compared with locals, rural non-locals were more concerned about vaccine side effects (β=0.26, 95% CI=0.07, 0.46), vaccine safety (β=0.42, 95% CI=0.19, 0.65), and vaccine effectiveness (β=0.37, 95% CI=0.16, 0.58). Conclusions Differences in vaccine hesitancy by residency could lead to geographical and sociodemographic disparities in vaccination coverage and outbreaks of vaccine-preventable disease. Supplement information This article is part of a supplement entitled Global Vaccination Equity, which is sponsored by the Global Institute for Vaccine Equity at the University of Michigan School of Public Health.

Although global progress in measles control has been realized, achieving elimination has proven difficult in many regions of the world. China has adopted a goal of measles elimination but recent outbreaks predominantly affecting children8 months who are ineligible for vaccination and incompletely protected by maternal antibodies has impeded progress. We assess the cost-effectiveness of adding an initial measles vaccine dose in China to earlier than the currently recommended 8 months of age.We conducted a cost-utility analysis comparing the costs and health benefits associated with adding a measles vaccine dose to the routine schedule at 4, 5, 6 or 7 months compared to the current recommendation for the first dose at age 8 months. A decision analytic model was developed in Microsoft Excel, including five non-severe and two fatal health outcomes associated with measles infection. Model parameters were informed by the literature and surveillance data. Future costs and health benefits were discounted at 3%. Primary outcomes included costs, Quality-adjusted life years (QALYs), and incremental cost-effectiveness ratio (ICER) over a lifetime time horizon.Lowering the recommended age for initiating the measles vaccination series to address susceptibility in children8 months provided incremental health gains compared to minimal costs at the individual-level. The ICER was most favorable ($232.70 per QALY gain) for administering an initial dose at 4 months of age due to fewer incremental program costs when shifting measles administration to an immunization visit already established under the Chinese vaccination program.We found potential beneficial health gains at a minimum cost associated with adding an earlier measles dose8 months of age in China. Further investigation about disease transmission dynamics is required to more fully assess the tradeoffs of administering measles at a younger age to infants in China.

Background Adults with chronic conditions such as heart disease, diabetes, or lung disease are more likely to develop complications from a number of vaccine-preventable diseases, including influenza and pneumonia. In this study, we use the data from a chronic disease management information system in Shanghai to estimate vaccination coverage and characterize predictors of seasonal influenza and 23-valent pneumococcal polysaccharide vaccine (PPSV23) vaccination among people with chronic disease in Shanghai. Methods The Shanghai Centers for Disease Control and Prevention have information systems related to chronic disease management, hospital records, and immunizations. Data from individuals with hypertension, diabetes and chronic obstructive pulmonary disease (COPD) were abstracted during July 2017. The main outcome was coverage of pneumococcal and influenza vaccination. Vaccination coverage was calculated across demographic groups. Significance in bivariate associations was assessed through Pearson’s chi-square tests, and in multivariable models through logistic regression models with a forward stepwise method to select variables. Results In the sample of 2,531,227 individuals ≥15 years, 22.8% were vaccinated for pneumonia from January 2013 to July 2017, and the vaccination coverage of influenza in the 2016/17 influenza season was 0.4%. Vaccination coverage was highest in those 70–79 and lowest in those younger than 60. Compared to urban areas, uptake in rural areas was higher for pneumonia vaccination (OR: 2.43, 95% CI: 2.41, 2.45), but lower for influenza vaccination (OR: 0.55, 95% CI: 0.51, 0.59). Having a greater number of chronic diseases was associated with higher likelihood of pneumonia vaccination (3 vs 1: OR: 1.68, 95% CI: 1.64, 1.71), but this relationship was not statistically significant for influenza vaccination. Conclusions We found low levels with of pneumococcal vaccination, and extremely low uptake of influenza vaccination among individuals with high risk conditions in Shanghai who should be priority groups targeted for vaccination. Interventions could be designed to target groups with low uptake – like younger adults, and individuals who have not yet retired.

Kenya has a significant refugee population, including large numbers of Somali migrants. This study examines the vaccination status of Kenyan children and sociodemographic predictors of vaccination, including Somali ethnicity. Using the 2014 Kenyan Demographic and Health Survey, we calculated the proportion of non-vaccinated, under-vaccinated, and fully vaccinated children, defining full vaccination as one dose Bacille Calmette-Guerin, three doses polio, three doses pentavalent, and one dose measles. We assessed associations among various factors and vaccination status using multinomial logistic regression and explored the effect of Somali ethnicity through interaction analysis. The study sample comprised 4052 children aged 12–23 months, with 79.4% fully, 19.0% under-, and 1.6% non-vaccinated. Among Somalis, 61.9% were fully, 28.7% under-, and 9.4% non-vaccinated. Somalis had significantly greater odds of under- and non-vaccination than the Kikuyu ethnic group. Wealth and birth setting were associated with immunization status for Somalis and non-Somalis. Disparities persist in pediatric vaccinations in Kenya, with Somali children more likely than non-Somalis to be under-vaccinated. Health inequalities among migrants and ethnic communities in Kenya should be addressed.