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Infectious Diseases (London, England) May 2022The number needed to vaccinate (NNV) quantifies the effectiveness of vaccination programs. We summarised the published data on NNV against herpes zoster to inform... (Meta-Analysis)
Meta-Analysis
OBJECTIVES
The number needed to vaccinate (NNV) quantifies the effectiveness of vaccination programs. We summarised the published data on NNV against herpes zoster to inform vaccination policies.
METHODS
We systematically identified studies based on a priori established and registered methods. The main outcomes were the NNV against herpes zoster infection, hospitalisation and mortality. Where appropriate, we conducted meta-analyses using inverse variance, random-effects models, pooling estimated NNV with associated 95% confidence interval (CI). Statistical heterogeneity between pooled estimates was calculated using the statistic.
RESULTS
Out of 229 unique citations, we included eight nonrandomized studies. Among 50+ year-olds, the NNV against herpes zoster infection using the recombinant subunit vaccine was 11 (95%CI 8-14; = 0%; 3 studies) and variable ( = 94.4%; 7 studies) using live attenuated vaccine, ranging from 10 (95%CI 1-19) to 58 (95%CI 49-67). Among 65+ year-olds, the NNV against herpes zoster infection using the recombinant subunit vaccine was 12 (95%CI: 9-15; = 0%; 2 studies) and variable ( = 98.5%; 4 studies) using live attenuated vaccine, ranging from 14 (95%CI 5-23) to 75 (95%CI 66-84). The NNV against herpes zoster hospitalisation among 65+ year-olds using the live attenuated vaccine was 280 (95%CI 209-352; = 0%; 2 studies). There was a paucity of data to inform other meta-analyses.
CONCLUSION
Evidence on the NNV against herpes zoster is scarce. Vaccination with the recombinant subunit herpes zoster vaccine may be more effective than with the live attenuated vaccine in preventing infection among 50+ year-olds. More studies are needed for a stronger evidence base for decision-making.
Topics: Herpes Zoster; Herpes Zoster Vaccine; Herpesvirus 3, Human; Humans; Vaccination; Vaccines, Attenuated; Vaccines, Subunit
PubMed: 34962439
DOI: 10.1080/23744235.2021.2018493 -
Journal of Veterinary Internal Medicine 2024Equine herpes virus type 1 (EHV-1) infection in horses is associated with respiratory and neurologic disease, abortion, and neonatal death. (Meta-Analysis)
Meta-Analysis
BACKGROUND
Equine herpes virus type 1 (EHV-1) infection in horses is associated with respiratory and neurologic disease, abortion, and neonatal death.
HYPOTHESIS
Vaccines decrease the occurrence of clinical disease in EHV-1-infected horses.
METHODS
A systematic review was performed searching multiple databases to identify relevant studies. Selection criteria were original peer-reviewed research reports that investigated the in vivo use of vaccines for the prevention of disease caused by EHV-1 in domesticated horses. Main outcomes of interest included pyrexia, abortion, neurologic disease, viremia, and nasal shedding. We evaluated risk of bias, conducted exploratory meta-analyses of incidence data for the main outcomes, and performed a GRADE evaluation of the quality of evidence for each vaccine subtype.
RESULTS
A total of 1018 unique studies were identified, of which 35 met the inclusion criteria. Experimental studies accounted for 31/35 studies, with the remainder being observational studies. Eight vaccine subclasses were identified including commercial (modified-live, inactivated, mixed) and experimental (modified-live, inactivated, deletion mutant, DNA, recombinant). Risk of bias was generally moderate, often because of underreporting of research methods, and sample sizes were small leading to imprecision in the estimate of the effect size. Several studies reported either no benefit or minimal vaccine efficacy for the primary outcomes of interest. Meta-analyses revealed significant heterogeneity was present, and our confidence in the quality of evidence for most outcomes was low to moderate.
CONCLUSIONS AND CLINICAL IMPORTANCE
Our review indicates that commercial and experimental vaccines minimally reduce the incidence of clinical disease associated with EHV-1 infection.
Topics: Animals; Horses; Herpesvirus 1, Equid; Horse Diseases; Herpesviridae Infections; Vaccination; Herpesvirus Vaccines; Viral Vaccines
PubMed: 37930113
DOI: 10.1111/jvim.16895