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Background: The herpes zoster vaccine is effective in preventing herpes zoster and postherpetic neuralgia in immunocompetent older adults. However, its safety has not been described in depth.Objective: To describe local adverse effects and short- and long-term safety profiles of herpes zoster vaccine in immunocompetent older adults.Design: Randomized, placebo-controlled trial with enrollment from November 1998 to September 2001 and follow-up through April 2004 (mean, 3.4 years). A Veterans Affairs Coordinating Center generated the permutated block randomization scheme, which was stratified by site and age. Participants and follow-up study personnel were blinded to treatment assignments. (ClinicalTrials.gov registration number: NCT00007501)Setting: 22 U.S. academic centers.Participants: 38 546 immunocompetent adults 60 years or older, including 6616 who participated in an adverse events substudy.Intervention: Single dose of herpes zoster vaccine or placebo.Measurements: Serious adverse events and rashes in all participants and inoculation-site events in substudy participants during the first 42 days after inoculation. Thereafter, vaccination-related serious adverse events and deaths were monitored in all participants, and hospitalizations were monitored in substudy participants.Results: After inoculation, 255 (1.4%) vaccine recipients and 254 (1.4%) placebo recipients reported serious adverse events. Local inoculation-site side effects were reported by 1604 (48%) vaccine recipients and 539 (16%) placebo recipients in the substudy. A total of 977 (56.6%) of the vaccine recipients reporting local side effects were aged 60 to 69 years, and 627 (39.2%) were older than 70 years. After inoculation, herpes zoster occurred in 7 vaccine recipients versus 24 placebo recipients. Long-term follow-up (mean, 3.39 years) showed that rates of hospitalization or death did not differ between vaccine and placebo recipients.Limitations: Participants in the substudy were not randomly selected. Confirmation of reported serious adverse events with medical record data was not always obtained.Conclusion: Herpes zoster vaccine is well tolerated in older, immunocompetent adults.Primary Funding Source: Cooperative Studies Program, Department of Veterans Affairs, Office of Research and Development; grants from Merck to the Veterans Affairs Cooperative Studies Program; and the James R. and Jesse V. Scott Fund for Shingles Research. [ABSTRACT FROM AUTHOR]

Several vaccine candidates to protect against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or coronavirus disease 2019 (COVID-19) have entered or will soon enter large-scale, phase 3, placebo-controlled randomized clinical trials. To facilitate harmonized evaluation and comparison of the efficacy of these vaccines, a general set of clinical endpoints is proposed, along with considerations to guide the selection of the primary endpoints on the basis of clinical and statistical reasoning. The plausibility that vaccine protection against symptomatic COVID-19 could be accompanied by a shift toward more SARS-CoV-2 infections that are asymptomatic is highlighted, as well as the potential implications of such a shift.

Background: In phase 3 trials, inactivated varicella zoster virus (VZV) vaccine (ZV IN ) was well tolerated and efficacious against herpes zoster (HZ) in autologous hematopoietic stem cell transplant (auto-HSCT) recipients and patients with solid tumor malignancies receiving chemotherapy (STMc) but did not reduce HZ incidence in patients with hematologic malignancies (HMs). Here, we describe ZV IN immunogenicity from these studies., Methods: Patients were randomized to ZV IN or placebo (4 doses). Immunogenicity was assessed by glycoprotein enzyme-linked immunosorbent assay (gpELISA) and VZV interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) assay in patients receiving all 4 doses without developing HZ at the time of blood sampling., Results: Estimated geometric mean fold rise ratios (ZV IN /placebo) by gpELISA and IFN-y ELISPOT ~28 days post-dose 4 were 2.02 (95% confidence interval [CI], 1.53-2.67) and 5.41 (95% CI, 3.60-8.12) in auto-HSCT recipients; 1.88 (95% CI, 1.79-1.98) and 2.10 (95% CI, 1.69-2.62) in patients with STMc; and not assessed and 2.35 (95% CI, 1.81-3.05) in patients with HM., Conclusions: ZV IN immunogenicity was directionally consistent with clinical efficacy in auto-HSCT recipients and patients with STMc even though HZ protection and VZV immunity were not statistically correlated. Despite a lack of clinical efficacy in patients with HM, ZV IN immunogenicity was observed in this population. Immunological results did not predict vaccine efficacy in these 3 populations., Clinical Trial Registration: NCT01229267, NCT01254630., (© The Author(s) 2020. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: Patients who are immunocompromised because of malignancy have an increased risk of herpes zoster and herpes zoster-related complications. We aimed to investigate the efficacy and safety of an inactivated varicella zoster virus (VZV) vaccine for herpes zoster prevention in patients with solid tumour or haematological malignancies., Methods: This phase 3, two-arm, randomised, double-blind, placebo-controlled, multicentre trial with an adaptive design was done in 329 centres across 40 countries. The trial included adult patients with solid tumour malignancies receiving chemotherapy and those with haematological malignancies, either receiving or not receiving chemotherapy. Patients were randomly assigned (1:1) to receive four doses of VZV vaccine inactivated by γ irradiation or placebo approximately 30 days apart. The patients, investigators, trial site staff, clinical adjudication committee, and sponsor's clinical and laboratory personnel were masked to the group assignment. The primary efficacy endpoint was herpes zoster incidence in patients with solid tumour malignancies receiving chemotherapy, which was assessed in the modified intention-to-treat population (defined as all randomly assigned patients who received at least one dose of inactivated VZV vaccine or placebo). The primary safety endpoint was serious adverse events up to 28 days after the fourth dose in patients with solid tumour malignancies receiving chemotherapy. Safety endpoints were assessed in all patients who received at least one dose of inactivated VZV vaccine or placebo and had follow-up data. This trial is registered (NCT01254630 and EudraCT 2010-023156-89)., Findings: Between June 27, 2011, and April 11, 2017, 5286 patients were randomly assigned to receive VZV vaccine inactivated by γ irradiation (n=2637) or placebo (n=2649). The haematological malignancy arm was terminated early because of evidence of futility at a planned interim analysis; therefore, all prespecified haematological malignancy endpoints were deemed exploratory. In patients with solid tumour malignancies in the modified intention-to-treat population, confirmed herpes zoster occurred in 22 of 1328 (6·7 per 1000 person-years) VZV vaccine recipients and in 61 of 1350 (18·5 per 1000 person-years) placebo recipients. Estimated vaccine efficacy against herpes zoster in patients with solid tumour malignancies was 63·6% (97·5% CI 36·4 to 79·1), meeting the prespecified success criterion. In patients with solid tumour malignancies, serious adverse events were similar in frequency across treatment groups, occurring in 298 (22·5%) of 1322 patients who received the vaccine and in 283 (21·0%) of 1346 patients who received placebo (risk difference 1·5%, 95% CI -1·7 to 4·6). Vaccine-related serious adverse events were less than 1% in each treatment group. Vaccine-related injection-site reactions were more common in the vaccine group than in the placebo group. In the haematological malignancy group, VZV vaccine was well tolerated and estimated vaccine efficacy against herpes zoster was 16·8% (95% CI -17·8 to 41·3)., Interpretation: The inactivated VZV vaccine was well tolerated and efficacious for herpes zoster prevention in patients with solid tumour malignancies receiving chemotherapy, but was not efficacious for herpes zoster prevention in patients with haematological malignancies., Funding: Merck & Co, Inc., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Zoster vaccine is a single dose live, attenuated vaccine (ZVL) indicated for individuals ≥50 years-old for the prevention of herpes zoster (HZ). Safety data from clinical trials and post-licensure studies provided reassurance that ZVL is generally safe and well tolerated. The objective of this review was to provide worldwide post-marketing safety information following 10 years of use and >34 million doses distributed., Methods: All post-marketing adverse experience (AE) reports received worldwide between 02-May-2006 and 01-May-2016 from healthcare professionals following vaccination with ZVL and submitted to the MSD AE global safety database, were analyzed., Results: A total of 23,556 AE reports, 93% non-serious, were reported. Local injection site reactions (ISRs), with a median time-to-onset of 2 days, were the most frequently reported AEs followed by HZ. The majority of HZ reports were reported within 2 weeks of vaccination and considered, based on time-to-onset, pathogenesis of HZ, and data from clinical trials, to be caused by wild-type varicella-zoster virus (VZV). HZ confirmed by PCR analysis to be VZV Oka/Merck vaccine-strain was identified in an immunocompetent individual 8 months postvaccination and in 4 immunocompromised individuals. Disseminated HZ was reported very rarely (<1%) with 38% occurring in immunocompromised individuals. All reports of disseminated HZ confirmed by PCR as VZV Oka/Merck vaccine-strain were in individuals with immunosuppressive conditions and/or therapy at the time of vaccination., Conclusions: The safety profile of ZVL, following 10 years of post-marketing use, was favorable and consistent with that observed in clinical trials and post-licensure studies., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Prevaccination and 6-week postvaccination samples from the immunogenicity substudy (n = 2269) of the zoster vaccine (ZV) efficacy trial (N = 22 439) in 50-59-year-old subjects were examined for varicella-zoster virus-specific antibody responses to vaccination. The varicella-zoster virus geometric mean titer (GMT) and geometric mean fold rise were higher in ZV recipients than in placebo recipients (GMT, 660.0 vs 293.1 glycoprotein enzyme-linked immunosorbent assay units/mL [P < .001], respectively; geometric mean fold rise, 2.31 vs 1.00 [P < .025]). In each group there was a strong inverse correlation between postvaccination GMT and risk of subsequent herpes zoster. Although these data provide strong evidence that relates ZV-induced antibody and the risk of herpes zoster, a protective threshold was not determined. Clinical Trials Registration. NCT00534248.

Background: Safety and immunogenicity of heat-treated zoster vaccine (ZVHT) were assessed in immunocompromised adults., Methods: In a randomized, double-blind, placebo-controlled, multicenter study, 4 doses ZVHT or placebo were administered approximately 30 days apart to adults with either solid tumor malignancy (STM); hematologic malignancy (HM); human immunodeficiency virus (HIV) with CD4(+) ≤200; autologous hematopoietic stem-cell transplant (HCT) or allogeneic-HCT recipients. Varicella-zoster virus (VZV) T-cell responses by interferon-γ enzyme-linked immunospot (IFN-γ ELISPOT) and VZV antibody concentrations by glycoprotein enzyme-linked immunosorbent assay (gpELISA) were measured at baseline and approximately 28 days after each dose., Results: No safety signals were found in any group. IFN-γ ELISPOT geometric mean fold rises (GMFR) after dose 4 in STM, HM, HIV, and autologous-HCT patients were 3.00 (P < .0001), 2.23 (P = .004), 1.76 (P = .026), and 9.01 (P = NA), respectively. Similarly, antibody GMFR were 2.35 (P < .0001), 1.28 (P = .003), 1.37 (P = .017), and 0.90 (P = NA), respectively. T-cell and antibody responses were poor after 4 doses of ZVHT in allogeneic-HCT patients., Conclusion: ZVHT was generally safe and immunogenic through 28 days post-dose 4 in adults with STM, HM, and HIV. Autologous-HCT but not allogeneic-HCT patients had a rise in T-cell response; antibody responses were not increased in either HCT population. Study identification. V212-002 Clinical Trials Registration. NCT00535236.

Background: After completion of the Shingles Prevention Study (SPS; Department of Veterans Affairs Cooperative Studies Program Number 403), SPS participants who had initially received placebo were offered investigational zoster vaccine without charge. This provided an opportunity to determine the relative safety of zoster vaccine in older adults following documented herpes zoster (HZ)., Methods: A total of 13 681 SPS placebo recipients who elected to receive zoster vaccine were followed for serious adverse events (SAE) for 28 days after vaccination. In contrast to the SPS, a prior episode of HZ was not a contraindication to receiving zoster vaccine. The SPS placebo recipients who received zoster vaccine included 420 who had developed documented HZ during the SPS., Results: The mean interval between the onset of HZ and the receipt of zoster vaccine in the 420 recipients with prior HZ was 3.61 years (median interval, 3.77 years [range, 3-85 months]); the interval was <5 years for approximately 80% of recipients. The proportion of vaccinated SPS placebo recipients with prior HZ who developed ≥ 1 SAE (0.95%) was not significantly different from that of vaccinated SPS placebo recipients with no prior history of HZ (0.66%), and the distribution of SAEs in the 2 groups was comparable., Conclusions: These results demonstrate that the general safety of zoster vaccine in older persons is not altered by a recent history of documented HZ, supporting the safety aspect of the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices recommendation to administer zoster vaccine to all persons ≥ 60 years of age with no contraindications, regardless of a prior history of HZ.

Background: Herpes zoster (HZ) adversely affects individuals aged 50-59, but vaccine efficacy has not been assessed in this population. This study was designed to determine the efficacy, safety, and tolerability of zoster vaccine for preventing HZ in persons aged 50-59 years., Methods: This was a randomized, double-blind, placebo-controlled study of 22 439 subjects aged 50-59 years conducted in North America and Europe. Subjects were given 1 dose of licensed zoster vaccine (ZV) (Zostavax; Merck) and followed for occurrence of HZ for ≥1 year (mean, 1.3 years) postvaccination until accrual of ≥96 confirmed HZ cases (as determined by testing lesions swabs for varicella zoster virus DNA by polymerase chain reaction). Subjects were followed for all adverse events (AEs) from day 1 to day 42 postvaccination and for serious AEs (SAEs) through day 182 postvaccination., Results: The ZV reduced the incidence of HZ (30 cases in vaccine group, 1.99/1000 person-years vs 99 cases in placebo group, 6.57/1000 person-years). Vaccine efficacy for preventing HZ was 69.8% (95% confidence interval, 54.1-80.6). AEs were reported by 72.8% of subjects in the ZV group and 41.5% in the placebo group, with the difference primarily due to higher rates of injection-site AEs and headache. The proportion of subjects reporting SAEs occurring within 42 days postvaccination (ZV, 0.6%; placebo, 0.5%) and 182 days postvaccination (ZV, 2.1%; placebo, 1.9%) was similar between groups., Conclusions: In subjects aged 50-59 years, the ZV significantly reduced the incidence of HZ and was well tolerated., Clinical Trials Registration: NCT00534248.

Background: Incidence and severity of herpes zoster (HZ) and postherpetic neuralgia increase with age, associated with age-related decrease in immunity to varicella-zoster virus (VZV). One dose of zoster vaccine (ZV) has demonstrated substantial protection against HZ; this study examined impact of a second dose of ZV., Methods: Randomized, double-blind, multicenter study with 210 subjects ≥60 years old compared immunity and safety profiles after one and two doses of ZV, separated by 6 weeks, vs. placebo. Immunogenicity was evaluated using VZV interferon-gamma (IFN-γ) enzyme-linked immunospot (ELISPOT) assay and VZV glycoprotein enzyme-linked immunosorbent antibody (gpELISA) assay. Adverse experiences (AEs) were recorded on a standardized Vaccination Report Card., Results: No serious vaccine-related AEs occurred. VZV IFN-γ ELISPOT geometric mean count (GMC) of spot-forming cells per 10(6) peripheral blood mononuclear cells increased in the ZV group from 16.9 prevaccination to 49.5 and 32.8 at 2 and 6 weeks postdose 1, respectively. Two weeks, 6 weeks and 6 months postdose 2, GMC was 44.3, 42.9, and 36.5, respectively. GMC in the placebo group did not change during the study. The peak ELISPOT response occurred ∼2 weeks after each ZV dose. The gpELISA geometric mean titers (GMTs) in the ZV group were higher than in the placebo group at 6 weeks after each dose. Correlation between the IFN-γ ELISPOT and gpELISA assays was poor., Conclusions: ZV was generally well-tolerated and immunogenic in adults ≥60 years old. A second dose of ZV was generally safe, but did not boost VZV-specific immunity beyond levels achieved postdose 1., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objective: To evaluate the general safety of zoster vaccine (ZV) in adults ≥60 years old., Patients/methods: Subjects were enrolled in a 1:1 ratio to receive 1 dose of ZV or placebo. Subjects were followed for serious adverse experiences (SAEs) for 42 days (primary follow-up period) and 182 days (secondary follow-up period) postvaccination. Relative-risks (ZV/placebo) for SAEs during both safety periods were calculated., Study Period: 17-Sep‑2007 to 09-Jan-2009., Results: Overall, 5,983 subjects received ZV and 5,997 received placebo. Within the primary 42-day follow-up period, 84 ZV subjects and 67 placebo subjects reported SAEs. The estimated risk of SAEs within 42 days was 1.41% for ZV versus 1.12% for placebo, with a relative-risk of 1.26 (95% CI 0.91,1.73); indicating no statistically significant difference between groups, meeting the pre-specified success criterion. During the 182-day follow-up period, 340 ZV subjects and 300 placebo subjects reported SAEs. The estimated risk of SAEs within 182 days was 5.68% for ZV versus 5.01% for placebo, with a relative-risk of 1.13 (95% CI 0.98,1.32), indicating no statistically significant difference between groups. Two subjects in the ZV group reported SAEs deemed by the investigator to be vaccine-related (uveitis and sciatica; onset Day 5 and 4, respectively). One subject in the placebo group reported a SAE deemed by the investigator to be vaccine-related (lumbar radiculopathy; onset Day 51). There were 24 fatal SAEs in the ZV group and 17 in the placebo group (relative risk = 1.41; CI: 0.77, 2.60); 6 and 5, respectively, with SAE onset during the primary 42-day follow-up period. No deaths were deemed vaccine-related., Conclusions: ZV and placebo groups had similar safety profiles in terms of SAEs during the primary (Day 1 to 42) and secondary (Day 1 to 182) follow-up periods.

This study evaluated safety & immunogenicity of ZOSTAVAX® (zoster vaccine: ZV) administered concomitantly versus nonconcomitantly with PNEUMOVAX® 23 (pneumococcal vaccine: PPV23). This randomized, double-blind, placebo-controlled study enrolled 473 subjects ≥60 years old in 1:1 ratio to receive ZV & PPV23 concomitantly (Day 1) or nonconcomitantly (PPV23 Day 1, ZV Week 4). Blood samples obtained for pneumococcal polysaccharide (PnPs) antibody (Ab) testing by enzyme-linked immunosorbent assay (ELISA) and varicella-zoster virus (VZV) Ab testing by glycoprotein ELISA. Subjects followed for adverse experiences (AEs) for 28 days postvaccination. Mean baseline VZV geometric mean titers (GMT) in nonconcomitant group were lower than concomitant group. Four weeks postvaccination with ZV, VZV Ab response in concomitant group was not similar to nonconcomitant group; estimated VZV GMT ratio [concomitant/nonconcomitant] was 0.70 (95% CI, 0.61-0.80). VZV Ab response was acceptable in concomitant group; estimated geometric mean foldrise (GMFR) from baseline was 1.9 (95% CI, 1.7-2.1). PnPs serotype-specific Ab responses were similar in both groups. All 6 reported serious AEs were deemed not related to study vaccine. Postvaccination of ZV, incidence of injection-site AEs was similar in both groups; clinical AEs were numerically but not significantly higher in nonconcomitant group. In summary, VZV GMT Ab response induced by ZV administered concomitantly with PPV23 was inferior to that induced nonconcomitantly. These results indicate that, to avoid a potential decrease in ZV immunogenicity, ZV & PPV23 should not be given concomitantly. Concomitant administration did not affect response to PPV23 serotypes tested. When administered concomitantly, ZV & PPV23 vaccines were generally well tolerated.

Background: Herpes zoster (HZ) incidence rises with age, especially after 50 years of age, probably due to waning varicella-zoster virus (VZV)-specific immunity. The Shingles Prevention Study [Oxman MN, Levin MJ, Johnson GR, Schmader KE, Straus SE, Gelb LD, et al. A vaccine to prevent herpes zoster and postherpetic neuralgia in older adults, N Engl J Med 2005;352:2271-84], enrolled people >/= 60 or years of age and showed that zoster vaccine prevents HZ and postherpetic neuralgia (PHN), presumably through boosting VZV-specific immunity. This study of people >/= 50 or years of age compared the safety and tolerability of two zoster vaccine potencies., Methods: Adults >/= 50 or years old enrolled in a randomized, double-blind, multicenter study to compare the safety and tolerability of one dose of two zoster vaccine potencies, approximately 58,000 and approximately 207,000 plaque-forming units/dose. Adverse experiences (AEs) were recorded on a standardized Vaccination Report Card for 42 days postvaccination. For assessment of injection-site AEs, clinically acceptable tolerability was predefined based on experience with PNEUMOVAX 23, a licensed vaccine recommended for use in older people., Results: Six hundred and ninety-eight subjects (age 50-90 years, median 64 years) were enrolled. No serious vaccine-related AEs were reported. Similar AE rates were observed in the higher and lower potency groups (overall systemic AEs: 37.5 and 39.3%, vaccine-related systemic AEs: 10.9 and 13.2%, injection-site AEs: 63.0 and 59.8%). Rates for a combined endpoint of moderate or severe injection-site pain/tenderness/soreness and swelling were 17.2% (95% CI 13.9, 21.0) and 9.0% (95% CI 5.6, 13.4), respectively. Most combined endpoint events were reported as moderate in intensity., Conclusions: Both vaccine potencies were generally well tolerated in this study of people > or years of age. Although rates of some moderate or severe injection-site AEs were greater in the higher potency group, all rates met the prespecified criteria for clinically acceptable tolerability.

Background: The incidence and severity of herpes zoster and postherpetic neuralgia increase with age in association with a progressive decline in cell-mediated immunity to varicella-zoster virus (VZV). We tested the hypothesis that vaccination against VZV would decrease the incidence, severity, or both of herpes zoster and postherpetic neuralgia among older adults., Methods: We enrolled 38,546 adults 60 years of age or older in a randomized, double-blind, placebo-controlled trial of an investigational live attenuated Oka/Merck VZV vaccine ("zoster vaccine"). Herpes zoster was diagnosed according to clinical and laboratory criteria. The pain and discomfort associated with herpes zoster were measured repeatedly for six months. The primary end point was the burden of illness due to herpes zoster, a measure affected by the incidence, severity, and duration of the associated pain and discomfort. The secondary end point was the incidence of postherpetic neuralgia., Results: More than 95 percent of the subjects continued in the study to its completion, with a median of 3.12 years of surveillance for herpes zoster. A total of 957 confirmed cases of herpes zoster (315 among vaccine recipients and 642 among placebo recipients) and 107 cases of postherpetic neuralgia (27 among vaccine recipients and 80 among placebo recipients) were included in the efficacy analysis. The use of the zoster vaccine reduced the burden of illness due to herpes zoster by 61.1 percent (P<0.001), reduced the incidence of postherpetic neuralgia by 66.5 percent (P<0.001), and reduced the incidence of herpes zoster by 51.3 percent (P<0.001). Reactions at the injection site were more frequent among vaccine recipients but were generally mild., Conclusions: The zoster vaccine markedly reduced morbidity from herpes zoster and postherpetic neuralgia among older adults., (Copyright 2005 Massachusetts Medical Society.)

The limited supple of appropriate tissues for study has been an impediment to investigations of varicella zoster virus (VZV) latency. Human dorsal root ganglia (DRG) harboring latent virus are not plentiful and are not amenable to manipulation for studying the events surrounding the establishment, maintenance, and cessation of latency. An alternative to studies in human DRG is the rat model of latency, which appears to provide a reliable method of investigating VZV latency. Other alternatives include studies in other human tissues involved in VZV pathogenesis. In order to improve our understanding of the establishment and cessation of latency, we performed comparative immunohistochemical analysis of chickenpox and zoster skin lesions. This analysis revealed that during primary infection and reactivation productive VZV infection occurs in a variety of cell types and that the major VZV DNA binding protein, ORF29p, is present in peripheral axons early during the course of chickenpox. VZV latency was studied in the rat model by in situ hybridization and compared with similar studies performed in human DRG containing latent virus, confirming that VZV DNA persists in the same sites in DRG of the two species.

Skin biopsy samples from varicella-zoster virus (VZV)-infected patients examined by immunohistochemistry demonstrated VZV replication in nonepithelial cell types. ORF29p, a nonstructural nuclear protein, was found in nerves of two of six patients with chickenpox. In tissue culture, ORF29p was secreted by VZV-infected fibroblasts. Extracellular ORF29p can be taken up through endocytosis by human neurons, implying a novel role for this protein in pathogenesis.

Varicella-Zoster virus (VZV) is a herpesvirus that becomes latent in sensory neurons after primary infection (chickenpox) and subsequently may reactivate to cause zoster. The mechanism by which this virus maintains latency, and the factors involved, are poorly understood. Here we demonstrate, by immunohistochemical analysis of ganglia obtained at autopsy from seropositive patients without clinical symptoms of VZV infection that viral regulatory proteins are present in latently infected neurons. These proteins, which localize to the nucleus of cells during lytic infection, predominantly are detected in the cytoplasm of latently infected neurons. The restriction of regulatory proteins from the nucleus of latently infected neurons might interrupt the cascade of virus gene expression that leads to a productive infection. Our findings raise the possibility that VZV has developed a novel mechanism for maintenance of latency that contrasts with the transcriptional repression that is associated with latency of herpes simplex virus, the prototypic alpha herpesvirus.

Ganglia obtained at autopsy were examined by in situ hybridization from one patient with zoster (also called herpes zoster or shingles), two varicella-zoster virus (VZV)-seropositive patients with clinical evidence of zoster, one VZV-seronegative child, and one fetus. Ganglia positive for VZV had a hybridization signal in both neuronal and nonneuronal satellite cells. Ganglia obtained from the fetus and from the seronegative infant were consistently negative for VZV. Two striking observations were evident regarding the presence of VZV DNA in ganglia obtained from the individual with zoster at the time of death. First, ganglia innervating the sites of reactivation and ganglia innervating adjacent sites yielded strongly positive signals in neurons and satellite cells, whereas ganglia from distant sites were rarely positive. Second, VZV DNA was found in both the nuclei and the cytoplasm of neurons innervating areas of zoster. However, in neurons innervating zoster-free areas, VZV DNA was found only in the nucleus of neurons and their supporting satellite cells. Immunohistochemistry with a fluorescent monoclonal antibody to the VZV glycoprotein gpI, a late virus protein, revealed a positive signal in the cytoplasm of ganglia with clinical evidence of reactivation. These results illustrate that both neuronal and satellite cells become latently infected following primary VZV infection. The presence of VZV DNA and gpI in the cytoplasm of neurons demonstrates productive infection following reactivation at the site of latency.

The K1 capsular polysaccharide, a polymer of sialic acid, is an important virulence determinant of extraintestinal pathogenic Escherichia coli. The genes responsible for the synthesis and expression of the polysialic acid capsule of E. coli K1 are located on the 17-kb kps gene cluster, which is functionally divided into three regions. Central region 2 encodes proteins necessary for the synthesis, activation, and polymerization of sialic acid, while flanking regions 1 and 3 are involved in polymer transport to the cell surface. In this study, we identified two genes at the proximal end of region 2, neuD and neuB, which encode proteins with predicted sizes of 22.7 and 38.7 kDa, respectively. Several observations suggest that the neuB gene encodes sialic acid synthase. EV24, a neuB chromosomal mutant that expresses a capsule when provided exogenous sialic acid, could be complemented in trans by the cloned neuB gene. In addition, NeuB has significant sequence similarity to the product of the cpsB gene of Neisseria meningitidis group B, which is postulated to encode sialic acid synthase. We also present data indicating that neuD has an essential role in K1 polymer production. Cells harboring pSR426, which contains all of region 2 but lacks region 1 and 3 genes, produce an intracellular polymer. In contrast, no polymer accumulated in cells carrying a derivative of pSR426 lacking a functional neuD gene. Unlike strains with mutations in neuB, however, neuD mutants are not complemented by exogenous sialic acid, suggesting that NeuD is not involved in sialic acid synthesis. Additionally, cells harboring a mutation in neuD accumulated sialic acid and CMP-sialic acid. We also found no significant differences between the endogenous and exogenous sialyltransferase activities of a neuD mutant and the wild-type organism. NeuD shows significant similarity to a family of bacterial acetyltransferases, leading to the theory that NeuD is an acetyltransferase which may exert its influences through modification of other region 2 proteins.

Objective: To compare the safety and immunogenicity of a three-component acellular pertussis (DTaP) vaccine containing pertussis toxin (PT), filamentous hemagglutinin (FHA), and pertactin with whole-cell pertussis (DTwP) vaccine in 4- through 6-year-old children., Participants: One hundred seventy-two healthy 4- through 6-year-old children previously immunized with the DTwP vaccine at or near 2, 4, 6, and 18 months of age., Interventions: Prevaccination serum samples were obtained on all study participants. One hundred twelve children received 0.5 mL of the DTaP vaccine intramuscularly. Fifty-three children received 0.5 mL of a commercially available DTwP vaccine intramuscularly. Approximately 30 days following vaccination, additional serum samples were obtained., Measurements: Parents monitored adverse reactions for 7 days following immunization. Significantly fewer children in the DTaP group reported temperatures of greater than 38.1 degrees C and an area of redness of more than 10 mm and moderate-to-severe pain at the injection site., Results: Antibody responses to PT, FHA, pertactin, and diphtheria and tetanus toxoids were measured by enzyme-linked immunosorbent assay. Among subjects who were seronegative prior to vaccination, response was defined as the detection of antibody levels following vaccination; among children with detectable antibody levels prior to vaccination, in terms of the rise in antibody titers. Data using a twofold and a fourfold rise in antibody titers as criteria to define response were evaluated. Children in the DTaP group had significantly greater increases in geometric mean titers of antibodies against PT, FHA, and pertactin. Over 90% of the DTaP group responded to PT, FHA, and pertactin according to the criteria of both the twofold and the fourfold rise in antibody titers. Significantly fewer of the DTwP group responded to PT, FHA, and pertactin with at least a fourfold rise in antibody titers. When analyzing subjects with at least a twofold increase in antibody titers, a statistically significant difference remained in regard to anti-FHA antibodies. All study subjects had protective antibody titers against diphtheria and tetanus toxoids following vaccination. The geometric mean titer of antibodies against tetanus was significantly greater in the DTwP group than in the DTaP group., Conclusion: The three-component DTaP vaccine administered as a booster immunization in 4-through 6-year-old children produced less fever and less redness and pain at the injection site than the DTwP vaccine and was as immunogenic as the DTaP vaccine.

While the incidence of HIV infection has leveled off in older homosexual men, infection in women, children, and adolescents is rising. Unless effective intervention measures are implemented, the number of pediatric patients with HIV and related illnesses will continue to increase. Interventions aimed at curtailing perinatal transmission potentially will have the greatest impact on decreasing the incidence of pediatric AIDS. Studies evaluating strategies aimed at this are currently underway. Educational initiatives targeting adolescents also may lower the number of pediatric patients with HIV infection. As treatments improve, the majority of HIV-infected children will survive for years and perhaps decades. The number of children with HIV infection in the upcoming decades will have a profound impact on our communities and our practice of pediatric medicine.