Efficacy, effectiveness, and safety of herpes zoster vaccines in adults aged 50 and older: systematic review and network meta-analysis 

• Systematic review and meta-analysis of  RCTs adults aged 50 and older. Over 2 million patients were included in the study
• The 27 studies were published between 1998 and 2017: nine in North America (33%), five in Europe (19%), two in Asia (7%), and 11 across several geographical regions (41%) (table 2, also see appendix S7). Twenty three of the trials were conducted across multiple study centers (74%) and 22 studies used a randomized controlled trial study design (81%). The average study duration was 30.9 months (SD 22.3 months). The live attenuated vaccine was the most commonly examined vaccine type (70%) and the incidence of suspected or confirmed herpes zoster was the most commonly examined outcome (81%).
• Twenty three studies (85%) included patients who were immunocompetent, and 22 studies (81%) included a sample consisting of more than 50% women (table 3, also see appendix S8). Twenty four studies (89%) included patients with no history of herpes zoster, and 18 studies included participants with documented varicella infection (67%).
• Compared the adjuvant recombinant vaccine to the live attenuated vaccine, placebo, or no vaccine for the prevention of herpes zoster infection
• The primary outcome studied vaccine efficacy for prevention of herpes zoster. Secondary outcomes included vaccine efficacy and effectiveness against post-herpetic neuralgia and herpes zoster ophthalmicus, quality of life, and vaccine safety including adverse events and death
• The results suggest that the adjuvant recombinant subunit vaccine is superior to the live attenuated vaccine for the prevention of herpes zoster infection, as measured by laboratory or doctor confirmed cases and suspected cases. 
• The superiority of the adjuvant recombinant subunit vaccine over the live attenuated vaccine in reducing the number of cases of herpes zoster ophthalmicus and post-herpetic neuralgia is inconclusive. 
• The adjuvant recombinant subunit vaccine was associated with more adverse events at injection sites than the live attenuated vaccine. There were no statistically significant differences shown between the vaccines for serious adverse events, withdrawals due to adverse events, potential immune mediated diseases, and death.

Link to article:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6201212/?report=printable