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.

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.

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).

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.

Development of a skin- and neuro-attenuated live vaccine for varicella.

Varicella caused by the primary infection of varicella-zoster virus (VZV) exerts a considerable disease burden globally. Current varicella vaccines consisting of the live-attenuated vOka strain of VZV are generally safe and effective. However, vOka retains full neurovirulence and can establish latency and reactivate to cause herpes zoster in vaccine recipients, raising safety concerns. Here, we rationally design a live-attenuated varicella vaccine candidate, v7D. This virus replicates like wild-type virus in MRC-5 fibroblasts and human PBMCs, the carrier for VZV dissemination, but is severely impaired for infection of human skin and neuronal cells. Meanwhile, v7D shows immunogenicity comparable to vOka both in vitro and in multiple small animal species. Finally, v7D is proven well-tolerated and immunogenic in nonhuman primates. Our preclinical data suggest that v7D is a promising candidate as a safer live varicella vaccine with reduced risk of vaccine-related complications, and could inform the design of other herpes virus vaccines.

The Childhood Vaccination Schedule and the Lack of Association With Type 1 Diabetes.

OBJECTIVES: Safety studies assessing the association between the entire recommended childhood immunization schedule and autoimmune diseases, such as type 1 diabetes mellitus (T1DM), are lacking. To examine the association between the recommended immunization schedule and T1DM, we conducted a retrospective cohort study of children born between 2004 and 2014 in 8 US health care organizations that participate in the Vaccine Safety Datalink. METHODS: Three measures of the immunization schedule were assessed: average days undervaccinated (ADU), cumulative antigen exposure, and cumulative aluminum exposure. T1DM incidence was identified by International Classification of Disease codes. Cox proportional hazards models were used to analyze associations between the 3 exposure measures and T1DM incidence. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were calculated. Models were adjusted for sex, race and ethnicity, birth year, mother's age, birth weight, gestational age, number of well-child visits, and study site. RESULTS: In a cohort of 584 171 children, the mean ADU was 38 days, the mean cumulative antigen exposure was 263 antigens (SD = 54), and the mean cumulative aluminum exposure was 4.11 mg (SD = 0.73). There were 1132 incident cases of T1DM. ADU (aHR = 1.01; 95% CI, 0.99-1.02) and cumulative antigen exposure (aHR = 0.98; 95% CI, 0.97-1.00) were not associated with T1DM. Cumulative aluminum exposure >3.00 mg was inversely associated with T1DM (aHR = 0.77; 95% CI, 0.60-0.99). CONCLUSIONS: The recommended schedule is not positively associated with the incidence of T1DM in children. These results support the safety of the recommended childhood immunization schedule.

Meningitis Caused by the Live Varicella Vaccine Virus: Metagenomic Next Generation Sequencing, Immunology Exome Sequencing and Cytokine Multiplex Profiling.

Varicella vaccine meningitis is an uncommon delayed adverse event of vaccination. Varicella vaccine meningitis has been diagnosed in 12 children, of whom 3 were immunocompromised. We now report two additional cases of vaccine meningitis in twice-immunized immunocompetent children and we perform further testing on a prior third case. We used three methods to diagnose or investigate cases of varicella vaccine meningitis, none of which have been used previously on this disease. These include metagenomic next-generation sequencing and cytokine multiplex profiling of cerebrospinal fluid and immunology exome analysis of white blood cells. In one new case, the diagnosis was confirmed by metagenomic next-generation sequencing of cerebrospinal fluid. Both varicella vaccine virus and human herpesvirus 7 DNA were detected. We performed cytokine multiplex profiling on the cerebrospinal fluid of two cases and found ten elevated biomarkers: interferon gamma, interleukins IL-1RA, IL-6, IL-8, IL-10, IL-17F, chemokines CXCL-9, CXCL-10, CCL-2, and G-CSF. In a second new case, we performed immunology exome sequencing on a panel of 356 genes, but no errors were found. After a review of all 14 cases, we concluded that (i) there is no common explanation for this adverse event, but (ii) ingestion of an oral corticosteroid burst 3-4 weeks before onset of vaccine meningitis may be a risk factor in some cases.

Parental acceptance and knowledge of varicella vaccination in relation to socioeconomics in Sweden: A cross-sectional study.

Varicella infection is a highly contagious disease which, whilst mild in most cases, can cause severe complications. Varicella vaccination is available privately in Sweden and is currently being reviewed for inclusion in the Swedish Public Health Agency's national immunisation program (NIP). A cross-sectional study of parents of Swedish children aged 1-8 years (n = 2212) was conducted to understand parental acceptance, beliefs and knowledge around varicella infection and vaccination. Respondents generally viewed varicella infection as a mild disease, with only a small proportion aware of potential severe complications. While 65% of respondents were aware of the vaccine, only 15% had started the course of vaccination as of February 2019. Further, 43% of parents did not intend to vaccinate, most commonly due to lack of inclusion in the NIP, but also due to perception of mild disease. Nevertheless, if offered within the NIP, 85% of parents would be highly likely to vaccinate their child. A number of statistically significant differences in awareness and behaviours were observed between sociodemographic subgroups. In general, women were more aware of vaccination (72%) compared to men (58%). Among unemployed or respondents with elementary school education, awareness was below 43%, and among respondents with high income the awareness was above 75%. Similarly, among unemployed or respondents with a low income the vaccination rate was as low as 30% compared with at least 57% among respondents with a high income. Respondents from metropolitan areas, those with university degrees and respondents with a higher income were more likely to be aware of the varicella vaccine and to have vaccinated their child. Whilst inclusion in the NIP is clearly the main driver for uptake, these identified knowledge gaps should inform educational efforts to ensure that all parents are informed of the availability and benefits of the varicella vaccine independent of socioeconomic status.

Waning Effectiveness of One-dose Universal Varicella Vaccination in Korea, 2011-2018: a Propensity Score Matched National Population Cohort.

BACKGROUND: Despite high coverage (~98%) of universal varicella vaccination (UVV) in the Republic of Korea since 2005, reduction in the incidence rate of varicella is not obvious. The study aimed to evaluate the vaccine effectiveness (VE) of one-dose UVV by timeline and severity of the disease. METHODS: All children born in Korea in 2011 were included for this retrospective cohort study that analyzed insurance claims data from 2011-2018 and the varicella vaccination records in the immunization registry. Adjusted hazard ratios by Cox proportional hazard models were used to estimate the VE through propensity score matching by the month of birth, sex, healthcare utilization rate, and region. RESULTS: Of the total 421,070 newborns in the 2011 birth cohort, 13,360 were matched for age, sex, healthcare utilization rate, and region by the propensity score matching method. A total of 55,940 (13.29%) children were diagnosed with varicella, with the incidence rate 24.2 per 1000 person-year; 13.4% of vaccinated children and 10.4% of unvaccinated children. The VE of one-dose UVV against any varicella was 86.1% (95% confidence interval [CI], 81.4-89.5) during the first year after vaccination and 49.9% (95% CI, 43.3-55.7) during the 6-year follow-up period since vaccination, resulting in a 7.2% annual decrease of VE. The overall VE for severe varicella was 66.3%. The VE of two-dose compared to one-dose was 73.4% (95% CI, 72.2-74.6). CONCLUSION: We found lower long-term VE in one-dose vaccination and waning of effectiveness over time. Longer follow ups of the vaccinated children as well as appropriately designed studies are needed to establish the optimal strategy in preventing varicella in Korea.

Impact of a two-dose varicella immunization program on the incidence of varicella: a multi-year observational study in Shanghai, China.

BACKGROUND: It remains hesitant to include a two-dose varicella vaccine (VarV) in a national routine immunization program in China. We aimed to quantify the impact of the two-dose VarV on varicella incidence in Shanghai. RESEARCH DESIGN AND METHODS: We directly extracted the data of varicella cases and VarV doses in 2013-2020 in Shanghai, and then estimated the effects of two-dose VarV using a Serfling model. RESULTS: A two-dose VarV immunization program has been extensively implemented since October 2017 and become free since August 2018 in Shanghai. Before and after this program, varicella cases significantly declined in children (P < 0.01), whereas did not in adults aged >18 years (P = 0.22). Compared to the predicted number of varicella cases, actual number was significantly lower by 8% in 2018 and 28% in 2019. Among children aged 4-6 years, the reduction in varicella cases was largest. Moreover, there was a significant reduction in varicella cases throughout 2020 (P < 0.001), in which the decrease due to social distancing for the COVID-19 was 54%. CONCLUSIONS: A two-dose VarV immunization program may further reduce approximately one-third of varicella cases in Shanghai. Children <4 years and adults benefit less in this program, which warrants enhancing the immunization.

Clinical and economic impact of universal varicella vaccination in Norway: A modeling study.

BACKGROUND: Norway has not implemented universal varicella vaccination, despite the considerable clinical and economic burden of varicella disease. METHODS: An existing dynamic transmission model of varicella infection was calibrated to age-specific seroprevalence rates in Norway. Six two-dose vaccination strategies were considered, consisting of combinations of two formulations each of a monovalent varicella vaccine (Varivax® or Varilrix®) and a quadrivalent vaccine against measles-mumps-rubella-varicella (ProQuad® or PriorixTetra®), with the first dose given with a monovalent vaccine at age 15 months, and the second dose with either a monovalent or quadrivalent vaccine at either 18 months, 7 or 11 years. Costs were considered from the perspectives of both the health care system and society. Quality-adjusted life-years saved and incremental cost-effectiveness ratios relative to no vaccination were calculated. A one-way sensitivity analysis was conducted to assess the impact of vaccine efficacy, price, the costs of a lost workday and of inpatient and outpatient care, vaccination coverage, and discount rate. RESULTS: In the absence of varicella vaccination, the annual incidence of natural varicella is estimated to be 1,359 per 100,000 population, and the cumulative numbers of varicella outpatient cases, hospitalizations, and deaths over 50 years are projected to be 1.81 million, 10,161, and 61, respectively. Universal varicella vaccination is projected to reduce the natural varicella incidence rate to 48-59 per 100,000 population, depending on the vaccination strategy, and to reduce varicella outpatient cases, hospitalizations, and deaths by 75-85%, 67-79%, and 75-79%, respectively. All strategies were cost-saving, with the most cost-saving as two doses of Varivax® at 15 months and 7 years (payer perspective) and two doses of Varivax® at 15 months and 18 months (societal perspective). CONCLUSIONS: All modeled two-dose varicella vaccination strategies are projected to lead to substantial reductions in varicella disease and to be cost saving compared to no vaccination in Norway.

Lack of persisting antibody in a post-transplant patient after vaccine-strain varicella.

BACKGROUND: LAVV have historically been avoided in children after solid organ transplantation. However, it has been reported that post-transplant, children without severe immunosuppression can generate anti-varicella antibody after immunization but the duration of the response is not clear. Furthermore, the origin of the varicella virus in immunosuppressed patients who develop varicella after vaccination is often unclear. CLINICAL PROGRESS: A female child received LAVV 30 months after a living donor liver transplant at the age of 2 months. Varicella rash appeared on the trunk 16 days after vaccination and gradually spread over the body. The patient was treated with intravenous acyclovir followed by oral therapy and recovered fully. The virus detected in blisters was derived from the vaccine-type strain. Paired sera before and after the onset of varicella showed an increase in antibody titer. However, 2 years after onset, the antibody titer decreased to undetectable again. CONCLUSIONS: This was an informative case of varicella due to vaccine strain attenuated virus. Antibody levels were not maintained over many years. Although varicella was caused by the vaccine-type strain, repeated vaccinations may be necessary for post-transplant patients who develop varicella.

Long -term persistence of antibodies against varicella in fully immunized healthcare workers: an Italian retrospective cohort study.

BACKGROUND: Chickenpox is a highly contagious disease caused by the varicella zoster virus (VZV), and in infants, adolescents, adults, pregnant women, and the immunocompromised it can be serious. The best way to prevent chickenpox is immunization with the varicella vaccine. Protective levels of antibodies induced by the varicella vaccine decline over time, but there is currently no formal recommendation for testing anti-varicella zoster virus (VZV) IgG levels in immunized healthcare workers (HCWs). METHODS: The aims of this study were to evaluate the seroprevalence of circulating anti-VZV IgG in a sample a sample of students and residents of the medical school of the University of Bari, the long-term immunogenicity of the varicella vaccine, and the effectiveness of a strategy consisting of a third vaccine booster dose. The study population was screened as part of a biological risk assessment conducted between April 2014 and October 2020. A strategy for the management of non-responders was also examined. RESULTS: The 182 students and residents included in the study had a documented history of immunization (two doses of varicella vaccine). The absence of anti-VZV IgG was determined in 34% (62/182; 95%CI = 27.2-41.4%), with serosusceptibility more common among males than females (p < 0.05). After a third varicella dose, seroconversion was achieved in 100% of this previously seronegative group. No serious adverse events were recorded. CONCLUSIONS: One-third of the study population immunized against VZV lacked a protective antibody titer, but a third dose of vaccine restored protection. Since it is highly unlikely that VZV will be eliminated in the immediate future, the loss of immunity in a substantial portion of the population implies a risk of varicella outbreaks in the coming years. Screening for varicella immunity in routine assessments of the biological risk of medical students and HCWs may help to prevent nosocomial VZV infections.

Immunogenicity and safety of a quadrivalent meningococcal tetanus toxoid-conjugate vaccine administered concomitantly with other paediatric vaccines in toddlers: a phase III randomised study.

Invasive meningococcal disease has high morbidity and mortality, with infants and young children among those at greatest risk. This phase III, open-label, randomised study in toddlers aged 12-23 months evaluated the immunogenicity and safety of meningococcal tetanus toxoid-conjugate vaccine (MenACYW-TT), a tetanus toxoid conjugated vaccine against meningococcal serogroups A, C, W and Y, when coadministered with paediatric vaccines (measles, mumps and rubella [MMR]; varicella [V]; 6-in-1 combination vaccine against diphtheria, tetanus, pertussis, polio, hepatitis B and Haemophilus influenzae type b [DTaP-IPV-HepB-Hib] and pneumococcal conjugate vaccine [PCV13])(NCT03205371). Immunogenicity to each meningococcal serogroup was assessed by serum bactericidal antibody assay using human complement (hSBA). Vaccine safety profiles were described up to 30 days post-vaccination. A total of 1183 participants were enrolled. The proportion with seroprotection (hSBA ≥1:8) to each meningococcal serogroup at Day 30 was comparable between the MenACYW-TT and MenACYW-TT + MMR + V groups (≥92 and ≥96%, respectively), between the MenACYW-TT and MenACYW-TT + DTaP-IPV-HepB-Hib groups (≥90% for both) and between the MenACYW-TT and MenACYW-TT + PCV13 groups (≥91 and ≥84%, respectively). The safety profiles of MenACYW-TT, and MMR + V, DTaP-IPV-HepB-Hib, and PCV13, with or without MenACYW-TT, were generally comparable. Coadministration of MenACYW-TT with paediatric vaccines in toddlers had no clinically relevant effect on the immunogenicity and safety of any of the vaccines.

Rubella immunity status and the active offer of MMR/MMRV vaccination during pregnancy.

INTRODUCTION: The rubella test during pregnancy makes it possible to identify situations at risk of congenital rubella and those pregnant mothers who should be offered the MMR vaccine. MATERIALS AND METHODS: The Authors analysed test coverage and the immunity status of pregnant mothers between 2005 and 2017, using birth attendance certificates. RESULTS: Rubella test coverage on 61,437 pregnant mothers was 99.4%. The average proportion of susceptible subjects was 6.4%. Seroconversion was observed in 7 cases, with 1 confirmed case of congenital rubella. 32% of susceptible subjects were vaccinated, and adherence was seen to be influenced by the characteristics of the pregnant women and of the maternity unit. CONCLUSIONS: A current information flow including a number of healthcare services, is useful both for monitoring the maternity care pathway and for public health purposes.

Acceptance of universal varicella vaccination among Swiss pediatricians and general practitioners who treat pediatric patients.

BACKGROUND: Over the last two decades, several countries have initiated universal varicella vaccination (UVV) programs in infants. In 2019, the Swiss National Immunization Technical Advisory Group (NITAG) decided to start evaluating the introduction of universal varicella vaccination. There is a theoretical concern that suboptimal vaccination coverage could lead to a shift in the varicella incidence to older age groups, thereby potentially increasing complication rates. To achieve a high vaccination coverage rate, it is important that practicing physicians comply with a potential recommendation for UVV. We studied the perception of varicella and the current vaccination behavior among Swiss pediatricians and general practitioners (GPs) who treat children. We also assessed their intention to advise parents to vaccinate their children against varicella in the event the Swiss NITAG will recommend UVV. METHODS: Primary data was collected through a structured, 20-min online survey with Swiss pediatricians and GPs who treat children. RESULTS: 150 physicians participated in the study: 40 GPs in the German-speaking part, 20 GPs in the French-speaking part, 67 pediatricians in the German-speaking part, and 23 pediatricians in the French-speaking part. The majority (64%) of all participants reported that they currently recommend varicella vaccination for risk groups according to the national immunization plan. About one third of physicians (35%) - predominantly pediatricians - currently already recommend it for all infants. In these situations, a measles, mumps, rubella, varicella combination vaccine is currently used by 58% for the first dose and by 59% for the second dose. 86% of participants stated that they would advise parents to have their children vaccinated against varicella in case of a recommendation for UVV by the Swiss NITAG. 68% responded that they expect many questions from parents and 65% agreed that they have good arguments to convey the importance of varicella vaccination. CONCLUSIONS: The survey study results show that most participating pediatricians and GPs indicated a favorable attitude towards childhood vaccination against varicella in the setting of a Swiss NITAG recommendation for UVV. This data shows the importance of NITAG recommendations in influencing vaccine education and supporting achievement of high coverage of varicella vaccination.

Safety of LAVs administered after pediatric LT.

Recent guidelines suggest that LAVs may be given to LT recipients meeting certain criteria. However, information is still limited. We sought to evaluate the safety of LAVs, including measles, mumps, rubella, and varicella to LT recipients following our clinically based immunization protocol for LT recipients. We conducted a case-series analysis on safety of LAVs for measles, rubella, varicella, and mumps given to LT recipients at our institution from July 2010 to July 2019. Patients who underwent LT at age <20 years who visited our immunization clinic were included. LT recipients were vaccinated if 2 years had lapsed from LT, had no signs of rejection within 6 months, and were on minimal immunosuppressants. Patient demographics, underlying diseases, type and number of vaccines administered, date of vaccination, and adverse events occurring within 4 weeks after vaccination were extracted from their medical records. During the study period, LAVs were administered 422 times to 209 patients who met criteria and included 225 doses of MR combination vaccine, 224 doses of varicella vaccine, and 215 doses of mumps vaccine. Underlying diseases included cholestatic liver diseases (n = 125), followed by metabolic diseases (n = 33) and acute liver failure (n = 19). Nine non-critical adverse events (2.1%) possibly associated with LAVs were reported, but there were no serious adverse events, including hospitalizations or deaths. In conclusion, LAVs administered to LT recipients were safe without any serious adverse events following our relatively simple institutional protocol.

WebPalestra: mudanças no Calendário Nacional de Vacinação para o ano 2018

Historicamente, diversos calendários de vacinação foram propostos pelo Programa Nacional de Imunizações em função de diferentes circunstâncias, tais como: situação epidemiológica, mudanças nas indicações das vacinas ou incorporação de novas vacinas. Para o ano de 2018, a Coordenação-Geral do Programa Nacional de Imunizações (CGPNI) informa mudanças para as seguintes vacinas do Calendário Nacional de Vacinação: vacina varicela, febre amarela e meningocócica C

[Systematic reviews and evidence quality assessment on effectiveness of 1 dose varicella attenuated live vaccine for healthy children aged 1-12 years in China].

Objective: To assess the effectiveness of 1 dose varicella attenuated live vaccine (VarV) for healthy children aged 1-12 years in China and explore the application of the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) framework in observational studies of vaccine effectiveness (VE). Methods: We searched studies about the VE of 1-dose VarV for children aged 1-12 years in China which published before 2019 and evaluated the quality of the studies by the Newcastle Ottawa Scale (NOS) table. We used Meta-analysis models to obtain the pooled 1-dose VE and that in subgroups by study design, outbreak or not, study quality and age of subjects. The evidences of VEs were rated by means of the GRADE system. Results: Thirty-two studies were included and the pooled 1-dose VE was 75% [95% confidence interval (CI): 68%-80%]. The VE of outbreak studies [VE=66% (95%CI: 57%-73%)] was lower than non-outbreak studies [VE=85% (95%CI: 78%-89%)], and the VE in <6 years old children [VE=84% (95%CI:77%-89%)] was higher than that in ≥6 years old children [VE=60% (95%CI: 51%-68%)]. There was no significant difference in VE among studies with different design and quality. The quality of the evidences of pooled 1-dose VE was"very low", which was downgraded in bias risk and inconsistency and not downgraded in indirectness, imprecision and publication bias. Conclusions: The 1-dose VarV can provide medium level protection for 1-12 years old children in China, but it will decrease significantly for ≥6 years old children, so it is suggested to implement the strategies of two-dose vaccination of VarV in children <6 years old. The GRADE framework can be used in the observational studies of VE and it is suggested that the technical guidelines of observational study should be worked out to improve the overall quality of evidence.