Herpes Zoster Vaccine Trials Meta-Analysis: Comparative Efficacy and Safety

Compared with the live zoster vaccine, adjuvanted recombinant zoster vaccine had significantly higher vaccine efficacy (VE) against herpes zoster (HZ) and postherpetic neuralgia in older adults. There were also no differences in safety between the 2 vaccines, according to a network meta-analysis of randomized controlled trials published in Vaccine.

This systematic review of published randomized controlled trials of the recombinant zoster vaccine and the live zoster vaccine was designed to determine the relative efficacy and safety of HZ prevention vaccines. Researchers included 25 studies in their review, of which 18 were included in the network meta-analysis. As a result of limited availability of data and both random and fixed effects for reactogenicity and safety outcomes, primary analyses included frequentist network meta-analyses with fixed effects for efficacy outcomes. VE analyses were stratified into 2 groups based on age (age > 60 years and age >70 years), as age has a proven effect on VE.

In both age groups, the recombinant zoster vaccine was significantly more effective against HZ than live zoster vaccine. In adults age > 60, the VE recombinant zoster vaccine was 0.92 (95% CI, 0.88-0.94), compared with VE for the live zoster vaccine of 0.51 (95% CI, 0.44-0.57). In adults age > 70, the VE of the recombinant zoster vaccine was 0.91 (95% CI, 0.87-0.94) compared with the VE for the live zoster vaccine of 0.37 (95% CI, 0.25-0.48).

The recombinant zoster vaccine was also significantly more effective against postherpetic neuralgia compared with live zoster vaccine both in adults age ≥60 (VE for the recombinant zoster vaccine = 0.89 [95% CI, 0.70-0.96] vs VE for the live zoster vaccine  = 0.66 [95% CI, 0.48-0.78]). In adults age ≥ 70 VE against postherpetic neuralgia for the recombinant zoster vaccine = 0.89 (95% CI, 0.69-0.96), compared with VE of live zoster vaccine = 0.67 (95% CI, 0.44-0.80). Although the recombinant zoster vaccine was associated with significantly more systemic and injection-site reactions compared with most live zoster vaccine formulations and placebo, definitions and data collection differed across the studies analyzed. No statistically significant differences in the prevalence of serious adverse events were found between the recombinant zoster vaccine and any live zoster vaccine formulation or placebo.

Study investigators concluded, “This analysis should further help policy-makers and public health officials to evaluate the different vaccines available for HZ in order to support evidence-based decisions. Although some of the individual studies in the analysis were quite large, the networks for individual outcomes were small, and the results should therefore be interpreted with caution. These results should be confirmed in the future as further data, such as studies conducted in real-life settings, become available. This NMA approach could also be applied to the evaluation of other vaccines in the future.”

Study funding was provided by GlaxoSmithKline Biologicals SA. GlaxoSmithKline Biologicals SA also funded all costs associated with the development and the publishing of the present manuscript. All authors had full access to the data and agreed with the submission of the publication.

Reference

McGirr A, Widenmaier R, Curran D, et al. The comparative efficacy and safety of herpes zoster vaccines: a network meta-analysis [published online April 11, 2019]. Vaccine. doi: 10.1016/j.vaccine.2019.04.014