Chickenpox in Poland in 2021. / Ospa wietrzna w Polsce w 2021 roku.

INTRODUCTION: Chickenpox is a highly contagious disease, but one that can be effectively prevented by vaccination. In Poland, vaccination against the disease is recommended, paid for, and chickenpox remains very common. In recent years, starting in 2002, the upward trend in the incidence of chickenpox has continued, except in 2020. In 2020, there was a decrease in incidence. OBJECTIVES: The aim of this study was to evaluate epidemiological indicators of chickenpox in Poland in 2021 compared to previous years, taking into account the impact of the COVID-19 pandemic. MATERIAL AND METHODS: The evaluation of the epidemiological situation of chickenpox in Poland in 2021 was carried out based on the results of the analysis of aggregate data published in the annual bulletins: "Infectious Diseases and Poisons in Poland in 2021" and "Immunization in Poland in 2021". In addition, recommendations from the 2021 Immunization Program are described. RESULTS: 57,669 cases of chickenpox were registered in Poland in 2021, 42% less than in the previous year. The incidence of chickenpox in 2021 was 151.1 per 100,000, which was lower than in 2020, as well as in 2019, when it was 470.6/100,000. The lowest incidence was registered in Lower Silesia Province - 99.2/100,000, while the highest in Silesia Province - 215.8/100,000. The highest incidence was in children aged 0-4 years (18,028). The incidence of chickenpox in males was higher than in females (159.5 vs. 143.3/100 thousand), and urban residents were higher than rural residents (152.1 vs. 149.6/100 thousand). Hospitalization due to chickenpox in 2021 included 210 people, which accounted for 0.36% of the total number of registered cases. CONCLUSIONS: In 2021, there was a decrease in the number of chickenpox cases compared to the previous year. The lower incidence may have been the result of a decrease in the transmission of the chickenpox virus, the decrease in the number of cases has to do with, among other things, the restrictions put in place in connection with the COVID-19 pandemic, which result in, among other things, reduced human contact, the wearing of masks and increased social distance.

The clinical and economic costs associated with regional disparities in varicella vaccine coverage in Italy over 50 years (2020-2070).

Italy implemented two-dose universal varicella vaccination (UVV) regionally from 2003 to 2013 and nationally from 2017 onwards. Our objective was to analyze regional disparities in varicella outcomes resulting from disparities in vaccine coverage rates (VCRs) projected over a 50-year time-horizon (2020-2070). A previously published dynamic transmission model was updated to quantify the potential public health impact of the UVV program in Italy at the national and regional levels. Four 2-dose vaccine strategies utilizing monovalent (V) and quadrivalent (MMRV) vaccines were evaluated for each region: (A) MMRV-MSD/MMRV-MSD, (B) MMRV-GSK/MMRV-GSK, (C) V-MSD/MMRV-MSD, and (D) V-GSK/MMRV-GSK. Costs were reported in 2022 Euros. Costs and quality-adjusted life-years (QALYs) were discounted 3% annually. Under strategy A, the three regions with the lowest first-dose VCR reported increased varicella cases (+ 34.3%), hospitalizations (+ 20.0%), QALYs lost (+ 5.9%), payer costs (+ 22.2%), and societal costs (+ 14.6%) over the 50-year time-horizon compared to the three regions with highest first-dose VCR. Regions with low first-dose VCR were more sensitive to changes in VCR than high first-dose VCR regions. Results with respect to second-dose VCR were qualitatively similar, although smaller in magnitude. Results were similar across all vaccine strategies.

An economic evaluation and incremental analysis of the cost effectiveness of three universal childhood varicella vaccination strategies for Ireland.

BACKGROUND: The cost effectiveness of childhood varicella vaccination is uncertain, as evidenced by variation in national health policies. Within the European Economic Area (EEA), only 10 of 30 countries offer universally funded childhood varicella vaccination. This study estimates the cost effectiveness of universal childhood varicella vaccination for one EEA country (Ireland), highlighting the difference in cost effectiveness between alternative vaccination strategies. METHODS: An age-structured dynamic transmission model, simulating varicella zoster virus transmission, was developed to analyse the impact of three vaccination strategies; one-dose at 12 months old, two-dose at 12 and 15 months old (short-interval), and two-dose at 12 months and five years old (long-interval). The analysis adopted an 80-year time horizon and considered payer and societal perspectives. Clinical effectiveness was based on cases of varicella and subsequently herpes zoster and post-herpetic neuralgia avoided, and outcomes were expressed in quality-adjusted life-years (QALYs). Costs were presented in 2022 Irish Euro and cost effectiveness was interpreted with reference to a willingness-to-pay threshold of €20,000 per QALY gained. RESULTS: From the payer perspective, the incremental cost-effectiveness ratio (ICER) for a one-dose strategy, compared with no vaccination, was estimated at €8,712 per QALY gained. The ICER for the next least expensive strategy, two-dose long-interval, compared with one-dose, was estimated at €45,090 per QALY gained. From a societal perspective, all three strategies were cost-saving compared with no vaccination; the two-dose short-interval strategy dominated, yielding the largest cost savings and health benefits. Results were stable across a range of sensitivity and scenario analyses. CONCLUSION: A one-dose strategy was highly cost effective from the payer perspective, driven by a reduction in hospitalisations. Two-dose strategies were cost saving from the societal perspective. These results should be considered alongside other factors such as acceptability of a new vaccine within the overall childhood immunisation schedule, programme objectives and budget impact.

Low vaccine coverage and varicella outbreaks in Brazil - 2019-2022.

The persistence of varicella outbreaks in Brazil has underscored the high concern with the low vaccine coverage in the last 4 years. Using publicly available data from the Brazilian Health System (SUS), this study analyzed varicella vaccine coverage and incidence trends from 2019 to 2022 in Brazilian States. Vaccine coverage decreased nationally in 2020, possibly influenced by the COVID-19 pandemic's initial phase. In Bahia State, we have the persistence of varicella with an incidence rate of 3.0 cases per 100,000 inhabitants (higher incidence compared to other States) in 2023. Under 15 months children and young children (4-6 Years old) faced the highest risk, urging the importance of vaccination. Despite a monovalent varicella vaccine being available through Brazil's National Immunization Program (NIP), Bahia fell short of achieving the ≥95 % disease control target for coverage. The study highlight the importance of vaccines to prevent some infectious diseases, as varicella, in poor tropical regions. Addressing vaccine hesitancy and misinformation, and augmenting awareness campaigns, are important to achieve and sustain high vaccine coverage over 80% as WHO guidelines to obtain a safe rate of protection for Brazilian population (Brazil's national immunization program has a target of 95% coverage).

Varicella in the 21st Century.

Varicella is a highly contagious disease caused by the varicella-zoster virus and has a wide range of clinical presentations. Varicella can cause mild disease in infants born to infected persons who are immunized as a result of previous vaccination or previous clinical or subclinical infection. However, varicella can also lead to severe life-threatening disease in infants, particularly for those born to nonimmunized persons. In this review, we will summarize the natural history of varicella-zoster infection in pregnant persons, infants with congenital varicella syndrome, and infants with postnatal varicella infection. We will also provide guidance about isolation recommendations and chemoprophylaxis for exposed hospitalized infants. Finally, we will describe risk factors for developing disseminated disease and review the approach to treatment of infected infants.

Serious neurological adverse events in immunocompetent children and adolescents caused by viral reactivation in the years following varicella vaccination.

Serious adverse events following vaccination include medical complications that require hospitalisation. The live varicella vaccine that was approved by the Food and Drug Administration in the United States in 1995 has an excellent safety record. Since the vaccine is a live virus, adverse events are more common in immunocompromised children who are vaccinated inadvertently. This review includes only serious adverse events in children considered to be immunocompetent. The serious adverse event called varicella vaccine meningitis was first reported in a hospitalised immunocompetent child in 2008. When we carried out a literature search, we found 15 cases of immunocompetent children and adolescents with varicella vaccine meningitis; the median age was 11 years. Eight of the children had received two varicella vaccinations. Most of the children also had a concomitant herpes zoster rash, although three did not. The children lived in the United States, Greece, Germany, Switzerland, and Japan. During our literature search, we found five additional cases of serious neurological events in immunocompetent children; these included 4 cases of progressive herpes zoster and one case of acute retinitis. Pulses of enteral corticosteroids as well as a lack of herpes simplex virus antibody may be risk factors for reactivation in immunocompetent children. All 20 children with adverse events were treated with acyclovir and recovered; 19 were hospitalised and one child was managed as an outpatient. Even though the number of neurological adverse events remains exceedingly low following varicella vaccination, we recommend documentation of those caused by the vaccine virus.

Immunogenicity and safety of live attenuated and recombinant/inactivated varicella zoster vaccines in people living with HIV: A systematic review.

Few papers focus their attention on VZV vaccination effectiveness among people living with HIV (PLWH). Flanking the live attenuated vaccine (VZL) available, a newly recombinant vaccine (RZV) was recently introduced and approved for HZ prevention among adults. PLWH represents a population on which a particular attention should be applied, in order to guarantee the vaccine efficacy and safety. We performed a literature search in USNLM, PubMed, PubMed Central, PMC and Cochrane Library. From all the publications found eligible, data were extracted and processed per population, vaccine type, immunogenicity and ADRs. The review of the 13 included studies shows that both RZV and VZL are immunogenic and have an acceptable safety profile in adults and children living with HIV. However, given the lack of research available about vaccine efficacy in preventing VZV and HZ in PLWH, additional studies need to be performed, in order to achieve a full completeness of data.

Live vaccinations in dermatology for immunosuppressed patients: a narrative review.

Given the higher susceptibility to infectious disease in patients receiving immunosuppressive therapies for inflammatory dermatologic conditions, immunization is important in this population. While live vaccines protect against life-threatening diseases, they can be harmful in immunosuppressed patients given the risk of replication of the attenuated pathogen and adverse reactions. The utilization of live vaccines in immunosuppressed patients depends on multiple factors such as the vaccine and therapy regimen. To provide an overview of evidence-based recommendations for the use of live vaccines in patients receiving immunosuppressive therapies for dermatological conditions. A literature search of the PubMed database was performed using keywords live vaccine, live-attenuated vaccine, dermatology, immunosuppressed, and immunocompromised, and specific immunosuppressive therapies: corticosteroids, glucocorticoids, methotrexate, azathioprine, cyclosporine, mycophenolate mofetil, biologics. Relevant articles written in English were included. Using these keywords, 125 articles were reviewed, of which 28 were ultimately selected. Recommendations for live vaccines can be determined on a case-by-case basis. Measles, mumps, rubella, varicella (MMRV) vaccines may be safely administered to patients on low-dose immunosuppressive agents while the yellow fever vaccine is typically contraindicated. It may be safe to administer live MMRV boosters to children on immunosuppressive therapies and the live herpes zoster vaccine to patients on biologics. Given poor adherence to immunization guidelines in immunosuppressed patients, dermatologists have a critical role in educating patients and general practitioners regarding live vaccines. By reviewing a patient's vaccination history and following immunization guidelines prior to initiating immunosuppressive therapies, physicians can mitigate morbidity and mortality from vaccine-preventable diseases.

Phase 3 Safety and Immunogenicity Study of a Three-dose Series of Twenty-valent Pneumococcal Conjugate Vaccine in Healthy Infants and Toddlers.

BACKGROUND: Global pediatric immunization programs with pneumococcal conjugate vaccines (PCVs) have reduced vaccine-type pneumococcal disease, but a substantial disease burden of non-PCV serotypes remains. METHODS: This phase 3, randomized (1:1), double-blind study evaluated safety and immunogenicity of 20-valent PCV (PCV20) relative to 13-valent PCV (PCV13) in healthy infants. Participants received 2 infant doses and a toddler dose of PCV20 or PCV13, with diphtheria-tetanus-acellular pertussis combination vaccine at all doses and measles, mumps, rubella and varicella vaccines at the toddler dose. Primary pneumococcal immunogenicity objectives were to demonstrate noninferiority (NI) of PCV20 to PCV13 for immunoglobulin G geometric mean concentrations after infant and toddler doses and percentages of participants with predefined serotype-specific immunoglobulin G concentrations after infant doses. Safety endpoints included local reactions, systemic events and adverse events. RESULTS: Overall, 1204 participants were vaccinated (PCV20, n = 601; PCV13, n = 603). One month after the toddler dose, 19/20 serotypes met NI for immunoglobulin G geometric mean concentrations; serotype 6B narrowly missed NI [PCV20/PCV13 geometric mean ratio: 0.57 (2-sided 95% confidence interval: 0.48-0.67); NI criterion: lower 2-sided 95% confidence interval >0.5]. Sixteen/twenty serotypes met NI for ≥1 primary objective after 2 infant doses. PCV20 induced robust opsonophagocytic activity, and boosting responses were observed for all vaccine serotypes, including those missing statistical NI. The safety/tolerability profile of PCV20 was like that of PCV13. CONCLUSIONS: PCV20 3-dose series in infants was safe and elicited robust immune responses. Based on these results and PCV13 experience, PCV20 3-dose series is expected to be protective for all 20 vaccine serotypes. NCT04546425.

Expanded spectrum of varicella disease and the need for vaccination in India.

Varicella vaccine was first licensed in Japan and South Korea in 1989 for use in healthy children and was introduced in US in 1995. So far, 29 countries have adopted varicella vaccine in their universal immunization program (UIP). No Asian country, India included, has adopted the varicella vaccine as part of their UIP. The extra-cutaneous sites for VZV diseases are central nervous system and gastrointestinal tract, the expanded disease spectrum includes vasculopathy, myelitis, inflammatory bowel disease, perforated ulcers, and gastritis. The actual disease burden of varicella is not known as most of the infected individuals may not visit the physician. The amplifiable VZV DNA will not always be detectable in cerebrospinal fluid (CSF) samples in protracted illnesses such as vasculopathies, but demonstrable anti-VZV IgG in CSF has diagnostic value. The World Health Organization (WHO) position paper 2014 recommends two doses of varicella and zoster vaccines in targeted population. In India, varicella vaccine is not included in the UIP due to the cost and the belief that lifelong immunity occurs following primary infection. The expanded spectrum of VZV disease and the mounting body of evidence, however, suggest the need for both varicella and zoster vaccines in routine immunization schedule.

Nanopore sequencing in distinguishing between wild-type and vaccine strains of Varicella-Zoster virus.

BACKGROUND: The introduction of varicella vaccines into routine pediatric immunization programs has led to a considerable reduction in varicella incidence. However, there have been reports of varicella, herpes zoster, and meningitis caused by the vaccine strain of varicella-zoster virus (VZV), raising concerns. Establishing the relationship between the wild-type and vaccine strains in VZV infections among previously vaccinated individuals is crucial. Differences in the single nucleotide polymorphisms (SNPs) among vaccine strains can be utilized to identify the strain. In this study, we employed nanopore sequencing to identify VZV strains and analyzed clinical samples. METHODS: We retrospectively examined vesicle and cerebrospinal fluid samples from patients with VZV infections. One sample each of the wild-type and vaccine strains, previously identified using allelic discrimination real-time PCR and direct sequencing, served as controls. Ten samples with undetermined VZV strains were included. After DNA extraction, a long PCR targeting the VZV ORF62 region was executed. Nanopore sequencing identified SNPs, allowing discrimination between the vaccine and wild-type strains. RESULTS: Nanopore sequencing confirmed SNPs at previously reported sites (105,705, 106,262, 107,136, and 107,252), aiding in distinguishing between wild-type and vaccine strains. Among the ten unknown samples, nine were characterized as wild strains and one as a vaccine strain. Even in samples with low VZV DNA levels, nanopore sequencing was effective in strain identification. CONCLUSION: This study validates that nanopore sequencing is a reliable method for differentiating between the wild-type and vaccine strains of VZV. Its ability to produce long-read sequences is remarkable, allowing simultaneous confirmation of known SNPs and the detection of new mutations. Nanopore sequencing can serve as a valuable tool for the swift and precise identification of wild-type and vaccine strains and has potential applications in future VZV surveillance.

Burden of chickenpox complications in Poland, 2006 to 2021: A comprehensive registry-based study.

BackgroundChickenpox, a vaccine-preventable disease caused by the varicella zoster virus, generally presents with mild symptoms but can cause complications necessitating hospitalisation. In Poland, since 2009, vaccination has been obligatory for children up to 12 years of age who are particularly vulnerable to infection and for children in their vicinity.AimTo examine the burden of chickenpox complications and the trends of hospitalisation arising from these complications over time in the Polish population.MethodsData spanning 2006-21 were sourced from the Polish Infectious Diseases Surveillance System, the Nationwide General Hospital Morbidity Study and the Statistics Poland death registry. Standardised and age-specific incidence rates, hospital discharge rates and number of deaths because of chickenpox were calculated. Moreover, the joinpoint regression model was used to analyse trends of annual hospital discharge rates.ResultsOver the analysed timeframe, 25,804 hospitalisations and 52 deaths attributable to chickenpox complications were documented, and 1.0% of chickenpox cases required hospitalisation because of chickenpox. Age-standardised hospitalisation rates varied between 2.3 and 9.6 per 100,000 population. The analysis revealed no statistically significant trend in overall hospital discharge rates from chickenpox complications. However, a notable increase in hospitalisation rates was observed in children aged 0-4 and among inhabitants of rural areas, with annual percentage changes of 4.9% and 3.4% respectively.ConclusionsOur findings suggest that the implementation of a universal chickenpox immunisation programme, supported by health education, should be considered to reduce the number of hospitalisations and nearly eliminate deaths because of chickenpox.

Varicella outbreak at nursery school under routine immunization in Japan in 2017 and 2018 and vaccine effectiveness.

BACKGROUND: In Japan, routine administration to one-year-old children of two-dose immunization for varicella was introduced in October 2014. Object The object of this study was to report outbreaks of varicella under routine immunization at a nursery school and in its surrounding area using data of surrounding areas from the (Nursery) School Absenteeism Surveillance System. Then, we measured the effectiveness of routine two-dose immunization for varicella to onset. We tentatively assessed its severity in a nursery school. METHOD: The study period extended from April 2017 through March 2018. The study area comprised Nursery school B and other nursery schools, and elementary and junior high schools in City A. Subjects in Nursery school B were 120 children. We analyzed vaccine effectiveness (VE) as an observational study and assessed severity using Fisher's exact test. We also assessed VE for severity using linear regression. Severity was defined as the length of nursery school absence attributable to varicella infection. RESULTS: During the one month preceding a period of two weeks before the initial case at Nursery school B, there were 16 cases of varicella infection in nursery schools, 45 cases in elementary schools, and one case in junior high schools in City A. For children who had received one vaccine dose or more, VE was 48.1% for all ages and 49.2% among children three years old and older. No significant VE against infection was found. Vaccination using one dose or more can reduce severity significantly. DISCUSSION AND CONCLUSION: Because many nursery school children who had received two doses of vaccine were infected, VE was estimated as low in the nursery school and not significant. Although VE for severity with more than one dose was confirmed, a second dose might not reduce severity compared to one dose.

UK healthcare professionals' attitudes towards the introduction of varicella vaccine into the routine childhood vaccination schedule and their preferences for administration.

BACKGROUND: Varicella (chickenpox) is a highly contagious disease caused by the varicella-zoster virus. Although typically mild, varicella can cause complications leading to severe illness and even death. Safe and effective varicella vaccines are available. The Joint Committee on Vaccination and Immunisation has reviewed the evidence and recommended the introduction of varicella vaccine into the UK's routine childhood immunisation schedule. OBJECTIVES: To explore UK healthcare professionals' (HCPs) knowledge and attitudes towards varicella vaccination, its introduction to the UK routine childhood immunisation schedule, and their preferences for how it should be delivered. DESIGN: We conducted an online cross-sectional survey exploring HCPs' attitudes towards varicella, varicella vaccine, and their preferences for delivery of the vaccine between August and September 2022 prior to the recommendation that varicella vaccine should be introduced. PARTICIPANTS: 91 HCPs working in the UK (81 % nurses/health visitors, 9 % doctors, 10 % researcher/other, mean age 48.7 years). RESULTS: All respondents agreed or strongly agreed that vaccines are important for a child's health. However, only 58% agreed or strongly agreed that chicken pox was a disease serious enough to warrant vaccination. Gaps in knowledge about varicella were revealed: 21.0% of respondents disagreed or were unsure that chickenpox can cause serious complications, while 41.8% were unsure or did not believe chickenpox was serious enough to vaccinate against. After receiving some basic information about chickenpox and the vaccine, almost half of the HCPs (47.3%) in our survey would prefer to administer the varicella vaccine combined with MMR. CONCLUSIONS: Given the positive influence of HCPs on parents' decisions to vaccinate their children, it is important to understand HCPs' views regarding the introduction of varicella vaccine into the routine schedule. Our findings highlighted areas for training and HCPs' preferences which will have implications for policy and practice when the vaccine is introduced.

A case series of live attenuated vaccine administration in dupilumab-treated children with atopic dermatitis.

BACKGROUND AND OBJECTIVE: Current regulatory labeling recommends avoiding live vaccine use in dupilumab-treated patients. Clinical data are not available to support more specific guidance for live or live attenuated vaccines administration in dupilumab-treated patients. METHODS: Children (6 months-5 years old) with moderate-to-severe atopic dermatitis (AD) enrolled in a phase 2/3 clinical trial of dupilumab (LIBERTY AD PRESCHOOL Part A/B; NCT03346434) and subsequently participated in the LIBERTY AD PED-OLE (NCT02612454). During these studies, protocol deviations occurred in nine children who received measles, mumps, rubella (MMR) vaccine with or without varicella vaccine; five with a ≤12-week gap between dupilumab administration and vaccination and four with a >12-week gap after discontinuing dupilumab. RESULTS: Nine children (1 female; 8 male) had severe AD at baseline (8-56 months old). Of the nine children, five had a ≤12-week gap ranged 1-7 weeks between dupilumab administration and vaccination who received MMR vaccine (n = 2) or MMR and varicella vaccines (n = 3); among these, one resumed dupilumab treatment as early as 2 days and four resumed treatment 18-43 days after vaccination. No treatment-emergent adverse events, including serious adverse events and infections, were reported within the 4-week post-vaccination period in any children. CONCLUSIONS: In this case series of dupilumab-treated children with severe AD who received MMR vaccine with or without varicella vaccine, no adverse effects (including vaccine-related infection) were reported within 4 weeks after vaccination. Further studies are warranted to evaluate the safety, tolerability, and immune response to live attenuated vaccines in dupilumab-treated patients.

Effectiveness of the combined MMRV Priorix-Tetra™ vaccine against varicella in a large Italian region: A case-control study.

Priorix-Tetra™ (MMRV GlaxoSmithKline Biologicals' vaccine) was developed based on the existing measles-mumps-rubella and varicella vaccines. In this study, we aimed to estimate the effectiveness of the combined measles-mumps-rubella-varicella Priorix-Tetra™ vaccine against varicella in real-world conditions. We conducted a post-marketing retrospective case-control study in the Apulia region of Italy in children aged 1-9 years born between January 1, 2008 and December 31, 2016. We assessed the effectiveness against varicella of all grades of severity (including hospitalisation) and against hospitalisation for varicella of a single and two doses of Priorix-Tetra™. Moreover, we also assessed effectiveness of monovalent varicella (monovalent-V) vaccine and any varicella vaccines. Vaccine effectiveness was calculated as (1-OR) x 100. We introduced demographic variables in the model to adjust Vaccine effectiveness (aVE) by potential confounders (sex and year of birth). We recorded 625 varicella cases and matched them with 1,875 controls. Among 625 cases, 198 had received a single MMRV dose, 10 two MMRV doses, 46 a single monovalent-V dose, none two monovalent-V doses; four a monovalent-V as first dose and MMRV as second dose, and one a MMRV as first dose and monovalent-V as second dose; 366 cases were not vaccinated. The aVE against varicella of all grades of severity was 77.0% and 93.0% after a single dose and after two doses of MMRV, respectively. The aVE against varicella of all grades was 72.0% after a single dose of monovalent-V vaccine. The aVE against varicella of all grades of severity was 76.0% after a single dose and 94.0% after two doses of any varicella vaccine. The aVE against varicella hospitalisation was 96% after a single dose of any varicella vaccine. Priorix-Tetra™ showed to be an effective vaccine and the two-dose schedule should be recommended to optimise immunisation programmes. A single dose was able to provide protection against varicella hospitalisation.

A retrospective cohort study evaluating the incidence of herpes zoster and postherpetic neuralgia after a live attenuated Oka-strain herpes zoster vaccine in a real-world setting in Japan.

BACKGROUND: In Japan, freeze-dried live attenuated Oka-strain varicella-zoster virus vaccine, VVL (BIKEN), is available for adults aged ≥50 years to prevent herpes zoster (HZ). Although an increase in the antibody titer and cellular immune response has been demonstrated following vaccination with VVL (BIKEN), to date, no clinical studies have shown that the vaccine decreases the incidence of HZ and postherpetic neuralgia (PHN). This study investigated the incidence of HZ and PHN among adults aged ≥50 years who received a single dose of VVL (BIKEN) to prevent HZ. METHODS: This retrospective cohort study investigated the incidence of HZ and PHN among adults aged ≥50 years who received a single dose of VVL (BIKEN) at a large hospital and affiliated clinics in Japan. A dispensing database and electronic medical records were used to identify vaccine recipients and cases of HZ and PHN. The end date of the follow-up period and the reason to end the follow-up were defined to avoid underestimating the incidence. The analysis was stratified according to age, sex, immunocompromising conditions, and use of immunosuppressant therapy. Vaccine effectiveness was estimated using published estimates of the incidence of HZ and PHN in the unvaccinated population in Japan. RESULTS: A total of 1175 patients were enrolled in the study. During a median follow-up period of 3.36 years, HZ was diagnosed in 27 participants (15 men [2.8%] and 12 women [1.9%]). The incidence of HZ among VVL (BIKEN) recipients was 7.67/1000 person-years. The incidence of PHN was 0.82/1000 person-years. The vaccine effectiveness was estimated as 27.8% [95% confidence interval (CI), -29.8 to 63.9%] and 73.8% [95% CI, 38.6-100%] against HZ and PHN, respectively. CONCLUSIONS: The VVL (BIKEN) had limited effectiveness at preventing HZ, but relatively good effectiveness at preventing PHN. VVL (BIKEN) might have a role as an affordable alternative.

Immunogenicity and safety of a live-attenuated varicella vaccine in a healthy population aged 13 years and older: A randomized, double-blind, controlled study.

OBJECTIVES: Vaccines for prevention against varicella are important for adolescents and adults, who have an increased risk of severe varicella. This study aimed to evaluate the immunogenicity and safety of a two-dose immunization schedule of a live-attenuated varicella vaccine (VarV) manufactured by Sinovac (Dalian) in healthy adolescents and adults. METHODS: A randomized, double-blind, controlled clinical trial was conducted in healthy population aged ≥ 13 years old in China. Participants in block 1 were randomly assigned (1:1) to receive two doses of either the test vaccine or an active control vaccine, administered 4, 6 or 8 weeks apart. Participants in block 2 were randomly assigned (2:1) to receive two doses of test vaccine or placebo, administered 10 weeks apart. The primary immunogenicity endpoint was the seroconversion rates and GMTs of varicella zoster virus (VZV) antibodies measured by fluorescent-antibody-to-membrane-antigen (FAMA) 4 weeks post-immunization. The primary safety endpoint was the incidence of adverse reactions within 4 weeks after each dose. RESULTS: A total of 2398 participants were enrolled. The seroconversion rates of VZV antibodies were 79.55 % in the test group and 76.41 % in the active control group respectively 4 weeks after two doses of pooled schedule, with the difference of 3.14 % (95 %CI: -0.69 %, 6.97 %). The GMTs were 1:162.07 and 1:160.04 respectively, with the ratio of 1.013 (95 %CI: 0.910, 1.127). Both the seroconversion rates and GMTs reached the prespecified non-inferiority criteria. Two-dose schedule with an interval of 10 weeks could also induce high immune responses, with a seroconversion rate of 83.22 % and a GMT of 1:160.38 in the test group. Safety profiles were similar among the test group, active control group and placebo group. CONCLUSION: VarV, manufactured by Sinovac (Dalian), demonstrated higher immune response and better flexibility in the immunization schedule among heathy population aged 13 years and older, without increased safety risk.

Parental perceptions of chickenpox and the varicella vaccine: A qualitative systematic review.

BACKGROUND: In countries where varicella vaccination is not on the routine childhood immunisation schedule, such as those in the United Kingdom (UK), chickenpox is an almost universal disease of childhood. Chickenpox can cause serious complications, particularly in infants, pregnant women, and the immunocompromised. In November 2023 the varicella vaccine was recommended for inclusion in the UK routine childhood immunisation schedule. Successful rollout of the vaccine may be hindered by parental concerns about vaccine safety and efficacy, and perceptions of chickenpox as a mild illness. OBJECTIVE: To examine parental perceptions of chickenpox and varicella vaccination, which may be crucial to effective vaccination campaigns. DESIGN: Qualitative systematic review and thematic analysis. METHODS: Six electronic databases were systematically searched for studies published between 2016 and 2023: CINAHL, EMBASE, MEDLINE, PsycInfo, PubMed, and Web of Science. The included studies were appraised against the Critical Appraisal Skills Program checklist for qualitative studies. Thematic analysis was used to analyse qualitative data, through the development of themes. RESULTS: 22 articles were included in this review, and five themes identified: perceptions that chickenpox is a mild illness, that parents have concerns about varicella vaccine efficacy and safety, a notion of natural immunity as superior, social determinants of health influence vaccine decision making, and vaccination is overwhelming perceived as a parental decision. CONCLUSIONS: Whilst some parents displayed an acceptance and willingness to vaccinate against chickenpox, many expressed concerns, and perceived chickenpox as a routine unworrying childhood illness. Analysis demonstrated a knowledge gap in understanding UK parental opinions regarding chickenpox and varicella vaccination, highlighting the need for research in this area, particularly given ongoing reconsideration for inclusion in the UK vaccination schedule. REGISTRATION: The review was registered on PROSPERO, registration ID CRD42021236120.

Progressive shingles in a toddler due to reactivation of Varicella Zoster vaccine virus four days after infection with SARS-CoV-2; a case report.

BACKGROUND: Herpes zoster (HZ) is the clinical syndrome associated with reactivation of latent varicella-zoster virus (VZV). Several factors have been implicated to promote VZV reactivation; these include immunosuppression, older age, mechanical trauma, physiologic stress, lymphopenia, and more recently, infection with severe acute respiratory syndrome coronavirus-2 (SARS- CoV-2). Recent reports suggest an increase in the number of HZ cases in the general population during the global COVID-19 pandemic. However, it is unknown what proportion of HZ during the pandemic is due to reactivation of wild-type or vaccine-strain VZV. CASE: Here we report the first known case of HZ concomitant with SARS-CoV2 infection in a 20-month-old female who was treated with a single dose of dexamethasone, due to reactivation of the vaccine-type strain of VZV after presenting with a worsening vesicular rash. CONCLUSION: In this case, we were able to show vaccine-strain VZV reactivation in the context of a mild acute symptomatic COVID-19 infection in a toddler. Being able to recognize HZ quickly and effectively in a pediatric patient can help stave off the significant morbidity and mortality associated with disease process.