Introducción:

Herpes zoster (HZ) commonly arises in older or immunocompromised individuals from the reactivation of latent varicella zoster virus. Without vaccination, up to 30% of people may develop HZ during their lifetime, with the risk increasing significantly after 50 years old (YO). In Argentina 27.0%-38.6% patients experience chronic postherpetic neuralgia (PHN) after the acute painful phase. HZ can cause ophthalmic, neurological, cutaneous, and visceral complications. The adjuvanted recombinant zoster vaccine (RZV) was recently introduced among 50+ YO people in the National Immunization Program (NIP) of Kingdom of Saudi Arabia.

Objetivos:

The aim of this study is to analyze the potential public health impact of introducing RZV in the 50+ YO Argentinian population compared with no vaccination.

Materiales y métodos:

The ZOster ecoNomic Analysis, a static multicohort Markov model over lifetime horizon, was adapted to the Argentinian setting. Population size (2022) and all-cause mortality (2010) were obtained from the National Institute of Statistics and Censuses website; HZ incidence from a worldwide meta-regression; proportions of PHN and other complications, number of doctor visits and hospitalization days from Argentinian local studies and vaccine efficacy from phase III clinical trials (ZOE-50 and ZOE-70). The coverage of RZV was assumed to be 35% with a second-dose compliance of 75%. One-way sensitivity analyses (OWSA) were conducted to assess the robustness of model results.

Resultados:

Without vaccination, Argentina’s 50+ YO population (n=11,952,880) could develop 2,053,714 HZ cases, 530,120 PHN cases, and 615,345 other non-pain complications over their lifetime, which could correspondingly incur 6,985,298 doctor visits and 899,034 hospitalization days from a health care resource utilization (HCRU) perspective. Vaccinating 35% of the 50+ YO population with RZV could avoid 426,055 HZ cases; 105,468 PHN cases; 127,657 HZ complications and prevent 1,449,140 doctor visits and 186,510 hospitalization days. The 50-59 YO age group had the highest contribution to the overall burden and reduction in HZ cases and related HCRU. 10 and 40 individuals need to be vaccinated to prevent 1 HZ case and 1 PHN case, respectively. In OWSA, the three most influential parameters are vaccine coverage, annual HZ incidence, and vaccine efficacy.

Discusión / Conclusiones:

Introducing RZV in NIP for 50+ YO people could substantially reduce the burden of HZ in Argentina.