Herpes zoster vaccine effectiveness against cardiovascular events - a systematic literature review and meta-analysis

Abstract Background Numerous studies have indicated an increased risk of stroke and myocardial infarction (MI) following herpes zoster (HZ); however, the impact of vaccination remains uncertain 1-4. Purpose To assess HZ vaccination effectiveness with recombinant zoster vaccine (RZV) or zoster vaccine live-attenuated (ZVL), against cardiovascular (CV) events (stroke, MI, or CV death) in adults aged ≥18 years and ≥50 years. Methods A global systematic literature review (Medline, Embase, Lilacs; 2004–2024) and meta-analysis were conducted of phase 3 randomized controlled trials (RCTs) and observational studies assessing the effect of HZ vaccination on CV events. Meta-analysis inclusion criteria followed Cochrane guidelines 5. Heterogeneity of included studies was examined by the I 2 index. Pooled risk ratio (RR) and 95% confidence interval (CI) were estimated with random-effects models. Results 19 studies were included in the review; eight observational studies and one RCT met the meta-analysis inclusion criteria for HZ vaccination effectiveness on CV events 6-14. Across all nine studies, 53.32% of participants were male. Seven studies reported mean ages from 53.6 years 6 to 74.0 years 13. No studies assessed CV deaths. Any HZ vaccination (RZV or ZVL) was associated with a significantly lower risk of stroke and MI, versus no HZ vaccination: pooled RR of 0.82 (95% CI 0.76–0.87) in adults ≥18 years and RR of 0.84 (0.82–0.87) in adults ≥50 years. Thus, vaccine effectiveness was 18% (13–24%) and 16% (13–18%) in preventing CV events, respectively (Figure 1). RZV vaccination was associated with a significantly lower risk of stroke and MI versus no HZ vaccination: pooled RR 0.79 (0.65–0.97) in adults ≥18 years and RR 0.79 (0.64–0.97) in adults ≥50 years, with a vaccine effectiveness of 21% (3–35%) and 21% (3–36%), respectively (Figure 2). Conclusions HZ vaccination (ZVL or RZV) was associated with a significantly lower rate of CV events. The potential cardioprotective effect of HZ vaccination could help to further reduce disease burden in adults, warranting further research.