OBJECTIVES: To perform a systematic literature review (SLR) of efficacy and reactogenicity/safety of vaccines for herpes zoster in adults ≥ 50 years of age based on evidence from randomized controlled trials.

METHODS: A systematic search was performed in May 2017 using predefined terms in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials in addition to manual searches of relevant non-indexed conferences. Standard SLR methodology was used to select relevant publications using predefined Population, Intervention, Comparators, and Study Design (PICOS) criteria. Quality was assessed at the trial level using the Cochrane Risk of Bias tool. Key outcomes extracted included efficacy (against herpes zoster (HZ), post-herpetic neuralgia, and other HZ complications, as well as HZ burden of illness mean score) and reactogenicity/safety (injection site/local reactions, systemic/general reactions, vaccine-associated systemic/general reactions, total discontinuations, and serious adverse events).

RESULTS: Of 1,290 unique publications retrieved for screening, 25 publications (associated with 21 unique trials and 108,678 patients) were included. There were 21 full texts and four conference abstracts all published between 1998 and 2017. Only two HZ vaccines were evaluated in the included studies: the candidate HZ adjuvanted subunit vaccine and Zoster Vaccine Live, although various routes of administration, formulations, doses, and schedules were assessed. Eight included articles (representing four trials and one sub-study) reported efficacy outcomes of interest, while 23 articles (representing 20 trials) reported reactogenicity/safety outcomes of interest.

CONCLUSIONS: This SLR provides a comprehensive overview of the literature reporting on the efficacy and reactogenicity/safety of HZ vaccines. Vaccines against HZ demonstrated favourable benefit risk profile. Given no head-to-head efficacy studies were identified, the relative merits of the individual formulations should be explored. Further investigation is needed to examine the appropriateness and feasibility of combining the extracted outcomes using meta-analysis or network meta-analysis and to define the best methodology to be used.