Herpes zoster vaccine safety in the Aotearoa New Zealand population: a self-controlled case series study.

In Aotearoa New Zealand, zoster vaccine live is used for the prevention of zoster and associated complications in adults. This study assessed the risk of pre-specified serious adverse events following zoster vaccine live immunisation among adults in routine clinical practice. We conducted a self-controlled case series study using routinely collected national data. We compared the incidence of serious adverse events during the at-risk period with the control period. Rate ratios were estimated using Conditional Poisson regression models. Falsification outcomes analyses were used to evaluate biases in our study population. From April 2018 to July 2021, 278,375 received the vaccine. The rate ratio of serious adverse events following immunisation was 0·43 (95% confidence interval [CI]: 0·37-0·50). There was no significant increase in the risk of cerebrovascular accidents, acute myocardial infarction, acute pericarditis, acute myocarditis, and Ramsay-Hunt Syndrome. The herpes zoster vaccine is safe in adults in Aotearoa New Zealand.

Herpes zoster vaccine effectiveness against herpes zoster and postherpetic neuralgia in New Zealand: a retrospective cohort study.

Background: Herpes zoster (HZ) and associated complications cause significant burden to older people. A HZ vaccination programme was introduced in Aotearoa New Zealand in April 2018 with a single dose vaccine for those aged 65 years and a four-year catch up for 66-80 year-olds. This study aimed to assess the 'real-world' effectiveness of the zoster vaccine live (ZVL) against HZ and postherpetic neuralgia (PHN). Methods: We conducted a nationwide retrospective matched cohort study from 1 April 2018 to 1 April 2021 using a linked de-identified patient level Ministry of Health data platform. A Cox proportional hazards model was used to estimate ZVL vaccine effectiveness (VE) against HZ and PHN adjusting for covariates. Multiple outcomes were assessed in the primary (hospitalised HZ and PHN - primary diagnosis) and secondary (hospitalised HZ and PHN: primary and secondary diagnosis, community HZ) analyses. A sub-group analysis was carried out in, adults ≥ 65 years old, immunocompromised adults, Maori, and Pacific populations. Findings: A total of 824,142 (274,272 vaccinated with ZVL matched with 549,870 unvaccinated) New Zealand residents were included in the study. The matched population was 93.4% immunocompetent, 52.2% female, 80.2% European (level 1 ethnic codes), and 64.5% were 65-74 years old (mean age = 71.1±5.0). Vaccinated versus unvaccinated incidence of hospitalised HZ was 0.16 vs. 0.31/1,000 person-years and 0.03 vs. 0.08/1000 person-years for PHN. In the primary analysis, the adjusted overall VE against hospitalised HZ and hospitalised PHN was 57.8% (95% CI: 41.1-69.8) and 73.7% (95% CI:14.0-92.0) respectively. In adults ≥ 65 years old, the VE against hospitalised HZ was 54.4% (95% CI: 36.0-67.5) and VE against hospitalised PHN was 75·5% (95% CI: 19.9-92.5). In the secondary analysis, the VE against community HZ was 30.0% (95% CI: 25.6-34.5). The ZVL VE against hospitalised HZ for immunocompromised adults was 51.1% (95% CI: 23.1-69.5), and PHN hospitalisation was 67.6% (95% CI: 9.3-88.4). The VE against HZ hospitalisation for Maori was 45.2% (95% CI: -23.2-75.6) and for Pacific Peoples was 52.2% (95% CI: -40.6 -83·7). Interpretation: ZVL was associated with a reduction in risk of hospitalisation from HZ and PHN in the New Zealand population. Funding: Wellington Doctoral Scholarship awarded to JFM.

Post-licensure zoster vaccine effectiveness against herpes zoster and postherpetic neuralgia in older adults: a systematic review and meta-analysis.

BACKGROUND: Given the substantial impact of herpes zoster on health and quality of life, and its considerable economic burden, prevention through vaccination is a priority. We aimed to evaluate the effectiveness of the herpes zoster vaccines (recombinant zoster vaccine [RZV] and zoster vaccine live [ZVL]) against incident herpes zoster and postherpetic neuralgia in older adults. METHODS: We did a systematic review and meta-analysis of studies assessing the effectiveness of herpes zoster vaccines in adults aged 50 years or older, compared with no vaccination or another vaccine. We searched published literature on MEDLINE, Embase, Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, ProQuest Central, and Dimensions, as well as unpublished studies, grey literature, and the reference lists of included studies. Observational studies published in any language between May 25, 2006, and Dec 31, 2020, were included. Eligible studies were appraised for methodological quality using standardised critical appraisal instruments from the Joanna Briggs Institute, and data were extracted from selected studies using a standardised tool. Random-effects meta-analysis models were used to estimate pooled vaccine effectiveness for outcomes of interest (herpes zoster, herpes zoster ophthalmicus, and postherpetic neuralgia) among clinically and methodologically comparable studies, with a fixed-effects model also used for herpes zoster ophthalmicus. Vaccine effectiveness was also assessed in people with comorbidities. As a post-hoc analysis, a forward citation search was done on Jan 31, 2021. This study is registered on PROSPERO, CRD42021232383. FINDINGS: Our search identified 1240 studies, of which 1162 were excluded based on title and abstract screening. A further 56 articles were excluded on reading the full text. 22 studies (21 cohort studies and one case-control study, involving 9 536 086 participants and 3·35 million person-years in the USA, UK, Canada, and Sweden) were included in the quantitative analysis. Of these, 13 articles were included in the meta-analysis. The overall quality of evidence was very low for all outcomes. The pooled vaccine effectiveness for ZVL against herpes zoster in adults was 45·9% (95% CI 42·2-49·4; seven studies). The vaccine effectiveness for ZVL against postherpetic neuralgia was 59·7% (58·4-89·7; three studies) and against herpes zoster ophthalmicus (in a fixed-effects model) was 30·0% (20·5-38·4; two studies). ZVL was effective in preventing herpes zoster in people with comorbidities, including diabetes (vaccine effectiveness 49·8%, 45·1-54·1; three studies), chronic kidney disease (54·3%, 49·0-59·1; four studies), liver disease (52·9%, 41·6-62·1; two studies), heart disease (52·3%, 45·0-58·7; two studies), and lung disease (49·0%, 32·2-66·2; two studies). In a post-hoc analysis of two studies from the USA published after 2020, the pooled vaccine effectiveness for RZV against herpes zoster in adults was 79·2% (57·6-89·7). Substantial heterogeneity (I2≥75%) was observed in 50% of the meta-analyses. INTERPRETATION: ZVL and RZV are effective in preventing herpes zoster in routine clinical practice. ZVL also reduces the risk of postherpetic neuralgia. Selection bias and confounding by unmeasured variables are inherent challenges of observational studies based on large health-care databases. Nevertheless, these findings will reassure policy makers, health practitioners, and the public that the vaccinations currently available for herpes zoster vaccination programmes are effective at preventing herpes zoster and related complications. FUNDING: None.

Postlicensure herpes zoster vaccine effectiveness: systematic review protocol.

INTRODUCTION: Herpes zoster (HZ) and associated complications inflict substantial morbidity and associated healthcare and socioeconomic burdens. Current treatments are not fully effective, especially among the most vulnerable populations. Two HZ vaccines are available and are part of the national immunisation programmes in many countries. This review will evaluate the effectiveness of zoster vaccines against incident HZ and postherpetic neuralgia in adults 50 years and older. METHODS AND ANALYSIS: The key information sources that will be searched include MEDLINE (Ovid), Embase (Ovid), Cochrane libraries and CINAHL. This search will consider postlicensure observational studies published in all languages between 2006 and 2020 that assessed the effectiveness of HZ/zoster vaccines in adults 50 years and older. The identification of studies will be complemented with the search of reference lists and citations, and contact with authors of papers to request missing or additional data, where required. Following the search, all identified citations will be collated, and duplicates will be removed. Titles and abstracts will then be screened by two independent reviewers for assessment against the inclusion criteria for the review. Selected studies will follow the process of critical appraisal, data extraction and data synthesis. Statistical analyses will be performed using a random-effect model. ETHICS AND DISSEMINATION: Formal ethical approval is not required, as primary data will not be collected. The review will be disseminated in peer-reviewed publications and conference presentations.