Effectiveness of Omicron JN.1 vaccination against infection with JN.1-derived SARS-CoV-2 subvariants in a prospective cohort study in the Netherlands
Vaccine·
- DOI
- 10.1016/j.vaccine.2026.129030
- PMID
- 42585808
- PMCID
- —
- OpenAlex
- W7202283909
- Study type
- Cohort study
- Publisher
- Elsevier BV
- Article type
- journal-article
- Integrity
- current
Why this research matters now
The findings indicate that JN.1 vaccination provided limited additional protection against SARS-CoV-2 infection during a low-incidence period, with modest effectiveness observed in both age groups. The results contribute to understanding the real-world performance of updated COVID-19 vaccines against emerging subvariants.
Structured evidence summary
Research question
The study estimated vaccine effectiveness of JN.1 COVID-19 vaccination against SARS-CoV-2 infection, including effectiveness against specific JN.1-derived subvariants KP.3.1.1 and XEC.
Study design
Prospective cohort study (VASCO) conducted in the Netherlands from September 2024 to February 2025. Participants completed questionnaires and serology testing, performed self-tests, and infection variants were identified through whole genome sequencing. Vaccine effectiveness was estimated using Cox regression with time-varying exposure and multinomial logistic regression with calendar-week matching, adjusting for demographic and clinical factors.
Population and setting
The cohort included JN.1 vaccine-eligible individuals: those aged 60 years and older, and those under 60 with medical risk conditions or healthcare workers. A total of 23,839 participants were analyzed, with vaccination uptake of 29% in the under-60 group and 74% in the 60-and-older group.
Main findings
During the five-month period, 2,142 infections occurred. Vaccine effectiveness was 16% in participants under 60 years and 13% in those 60 and older. No significant difference in effectiveness was detected between KP.3.1.1 and XEC subvariants, though point estimates suggested potentially lower protection against XEC.
Public-health relevance
The findings indicate that JN.1 vaccination provided limited additional protection against SARS-CoV-2 infection during a low-incidence period, with modest effectiveness observed in both age groups. The results contribute to understanding the real-world performance of updated COVID-19 vaccines against emerging subvariants.
Important limitations
The study had low statistical power to detect differences in vaccine effectiveness between subvariants. The analysis was conducted during a period of low SARS-CoV-2 incidence. Most infections were self-reported rather than laboratory-confirmed. This summary relies on the supplied abstract and metadata; the full paper is required for decision-grade interpretation.
GIDS interpretation
This article was identified through classifier links to COVID-19, SARS, vaccination topics, and the Netherlands geographic context. These links assist in literature discovery and thematic organization but do not indicate that this research was triggered by or confirms a specific surveillance signal.
Related GIDS surveillance
Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.
Evidence relationships
This article has 9 auditable classifier relationships to diseases, places, topics, and study design.