Long-term efficacy data for the recombinant zoster vaccine: impact on public health and cost effectiveness in Germany

PLAIN LANGUAGE SUMMARY What is the context? Shingles is a viral infection caused by the reactivation of the chickenpox virus. It causes a painful rash that lasts for several weeks. The incidence and severity of shingles increase with age. In Germany alone there are approximately 400,000 new cases annually. Vaccination can help prevent shingles. Previous studies, based on data collected up to four years post-vaccination, estimated the number of shingles cases prevented. What is new? Here, we use data from the same studies followed over a longer-term to update previous analyses in the German population. We found, based on data up to 8 years following vaccination, that: O In adults 50-69 years: the vaccine initially prevents 98.9% of cases, with a reduction of 1.5% each year(for example, after one year, it would prevent 97.4% of cases). O In adults over 70 years of age: the vaccine initially prevents 95.4% of cases, with a reduction of 2.3% each year (for example, after one year, it would prevent 93.1% of cases). O Vaccination would reduce the number of shingles cases by 0.9 million in a cohort of adults aged 50-59 years, 0.6 million in adults 60-69 years, and 0.5 million in adults older than 70 years, over the remainder of their lifetime. What is the impact? The study provides more certainty regarding results as it is based on the most complete/up to date data. The results showed the potential of Shingrix to prevent shingles while at the same time providing good value for money. The aim of the study was to update previously published public health impact and cost-effectiveness analyses of the recombinant zoster vaccine (RZV), in the German population aged >= 50 years of age (YOA), with the latest vaccine efficacy (VE) estimates against herpes zoster (HZ). The updated estimates are derived from a long-term follow-up study. A previously published multi-cohort Markov model following age cohorts over their lifetime was used. Demographic, epidemiological, cost, and utility data were based on German specific sources. Vaccine coverage was assumed to be 40%, with a second dose compliance of 70%. The estimated VE at time 0 was 98.9% (95% C.I.: 94.0-100%) with an annual waning of 1.5% (95% CI: 0.0-3.4%) for the age group 50-69 YOA. Corresponding values were 95.4% (95% C.I.: 89.7-100%) and 2.3% (95% CI: 0.3-4.4%) for the age group >= 70 YOA. It was estimated that, over the remaining lifetime since vaccination, RZV would prevent approximately 884 thousand (K), 603 K, and 538 K HZ cases in three age cohorts 50-59, 60-69, and >= 70 YOA, respectively. The number needed to vaccinate to prevent one HZ and one postherpetic neuralgia case was 6 and 36 (50-59 YOA cohort), 6 and 34 (60-69 YOA cohort), 10 and 48 (>= 70 YOA cohort). The incremental cost-effectiveness ratio of vaccination ranged from euro26 K/quality-adjusted life year (QALY) in 60 YOA to euro35 K/QALY in 70 YOA. Due to the higher, sustained, RZV VE, improved public health and cost-effectiveness results were observed compared to previous analyses.