Durability of the BNT162b2 XBB.1.5-adapted vaccine against JN.1 hospitalisation in Europe, October 2023 to August 2024: A test-negative case-control study using the id.DRIVE platform

BackgroundWhile multiple studies have shown that the BNT162b2 XBB.1.5-adapted mRNA COVID-19 vaccine (BNT162b2 XBB vaccine) is effective in preventing COVID-19 hospitalisation and death, effectiveness beyond six months remains unexplored. AimWe extended our previous study of BNT162b2 XBB vaccine effectiveness (VE) to evaluate durability against JN.1-related hospitalisation up to 46 weeks since dose using the id.DRIVE platform across Belgium, Germany, Italy, and Spain. MethodsThis multi-country, multi-centre test-negative case-control study assessed the effectiveness and durability of the BNT162b2 XBB vaccine in preventing JN.1-associated hospitalisation among adults with severe acute respiratory infection between October 2023 and August 2024. Each case was matched with up to four controls by symptom onset date and study site. Multivariable analyses were adjusted for symptom onset date, age, sex, number of chronic conditions, and influenza vaccination receipt. ResultsAmong 827 test-positive cases and 2232 test-negative controls, protection against hospitalisation was sustained from 2 to <30 weeks since dose, with evidence of significant waning thereafter. VE was 64.5% (95% CI: 56.6; 71.0) at 2 to <30 weeks, and 4.9% (95% CI: -30.3; 30.7) at 30 to <46 weeks. ConclusionsDespite the vaccine target not matching the predominant subvariant, BNT162b2 XBB vaccine protected against JN.1-related hospitalization for up to 30 weeks, but protection against hospitalisation was non-significant after 30 weeks since dose, potentially due to further shift in circulating SARS-CoV-2 strains and/or waning immunity. Given the high COVID-19 activity in Europe during summer 2024, an additional vaccination after six months is warranted for those at risk of COVID-19 hospitalisation to maintain year-round protection.