BNT162b2 JN.1-adapted vaccine effective against COVID-19 hospitalization
06 May 2025
byKanas Chan
BNT162b2 JN.1-adapted vaccine provides protection against COVID-19–related hospitalization in Europe, a case-control study using the id.DRIVE platform has shown.
Similar VE vs KP.2-adapted vaccine
The test-negative case-control study using the id.DRIVE platform was conducted in 529 adults (median age, 75.0 years; male, 52.9 percent) hospitalized with severe respiratory infection in nine study sites across Europe between September 2024 and January 2025. Only 7.8 percent of patients had never been vaccinated against COVID-19. [ESCMID Global 2025, abstract LB001]
After a median of 64 days since vaccination, the BNT162b2 JN.1-adapted vaccine’s adjusted vaccine effectiveness (VE) against COVID-19 hospitalization was 67.9 percent (95 percent confidence interval [CI], 38.6–83.3).
“[Notably], the adjusted VE closely aligned with the previously published VE estimate of 68 percent [95 percent CI, 42–82] for the BNT162b2 KP.2-adapted vaccine in US Veterans,” pointed out Dr Hannah Volkman of Pfizer Inc., New York, US, at ESCMID Global 2025.
Dr Hannah Volkman
When stratified by age, the adjusted VE of the BNT162b2 JN.1-adapted vaccine was similar for patients aged ≥65 years, at 65.7 percent (95 percent CI, 34.4–82), and for those aged 65–79 years, at 65.8 percent (95 percent CI, 34.4–82.0). However, the adjusted VE for patients aged 18–64 years and ≥80 years were less precise with wide CIs.
These results represent the first VE data for 2024–2025 COVID-19 vaccines in Europe, as no data were available prior to March 2025. “Further study on both JN.1- and KP.2-adapted vaccines is warranted with respect to durability and high-risk groups,” noted Volkman.
The need to stay up to date with vaccines
According to the WHO’s epidemiological update published on 17 March 2025, >16,700 new hospitalizations and 4,500 new deaths due to COVID-19 were recorded during the 28-day reporting period from 6 January to 2 February 2025. [www.who.int/publications/m/item/covid-19-epidemiological-update-edition-177]
Of note, most adults hospitalized for COVID-19 during the 2023–2024 season were not up to date with COVID-19 vaccines. Additionally, approximately 90 percent of hospitalizations due to COVID-19 occurred in patients with ≥1 medical condition, namely, cardiovascular disease, chronic lung disease, diabetes, immunocompromising conditions, neurological conditions, or severe obesity. [ESCMID Global 2025, abstract IS26]
JN.1 vaccines for 2024/25 season
JN.1 differs in >30 mutations in the spike protein compared with XBB.1.5, which was used for the 2023–2024 COVID-19 vaccines. JN.1 is the predominant variant in Europe and is rising sharply in Asia. The KP.2 subvariant is a descendant of and closely related to the JN.1 variant. [ESCMID Global 2025, abstract IS26; EMA Emergency Task Force, EMA/338472/2024]
As immunity to COVID-19 weans over time, primarily due to the emergence of new SARS-CoV-2 variants and the length of time since vaccination or infection, health authorities recommend the antigen composition of vaccines to maintain immune responses against circulating strains.
For the 2024–2025 season, the European Medicines Agency (EMA) Emergency Task Force recommends updating COVID-19 vaccines to target JN.1. Vaccine compositions targeting JN.1 subvariants could be considered if there is adequate justification. This position is in line with the WHO’s recommendation issued on 26 April 2024. [ESCMID Global 2025, abstract LB001; EMA Emergency Task Force, EMA/338472/2024]
