The efficacy, immunogenicity and safety of the LZ901 vaccine for herpes zoster virus in adults 40 years of age or older: a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial.

In previously completed Phase 1 and 2 clinical trials, a recombinant gE-Fc fusion protein subunit vaccine adjuvanted with aluminum hydroxide (called LZ901) demonstrated favorable safety profiles and elicited robust immune responses. This randomized, placebo-controlled, double-blind, phase 3 trial (ChiCTR2300076253) evaluated the efficacy and safety of LZ901 in adults ≥40 years. 26,018 participants received either two intramuscular doses of LZ901 (30-day interval; n = 13,010) or a placebo (30-day interval; n = 13,008). The primary objective was to assess herpes zoster risk within 12-months after LZ901 vaccination. During the follow-up period, 15 LZ901 recipients and 178 placebo recipients were confirmed positive for herpes zoster. Overall vaccine efficacy against herpes zoster was 91.6% (95% confidence interval, 86.3 to 95.3; p < 0.001); efficacy was higher in participants aged 40-69 years [93.9% (95% confidence interval, 89.1 to 97.0; p < 0.001)] than in participants aged ≥70 years [66.9% (95% confidence interval, 14.6 to 89.2; p = 0.016)]. Post-herpetic neuralgia occurred in 1 of 15 herpes zoster cases in the LZ901 group and in 24 of 187 herpes zoster cases in the placebo group, corresponding to a vaccine efficacy of 95.9% (95% confidence interval, 63.9 to 99.93; p < 0.001) against post-herpetic neuralgia. LZ901 recipients had more injection-site and systemic reactions within 7 days of vaccination compared to the placebo group; grade 3 reactions were comparably low in both the LZ901 and placebo groups (0.3% versus 0.4%, respectively). No serious adverse events or safety concerns associated with LZ901 were noted. LZ901 reduces the risk of herpes zoster in adults who were 40 years of age or older in 12 months, with a favorable safety profile.