Cardio-oncology & otherTrial design

A pragmatic randomized trial to evaluate the vaccine effectiveness of bivalent respiratory syncytial virus (RSV) prefusion F vaccine for preventing RSV hospitalizations in adults (DAN-RSV): Trial design update

Am Heart JPublished

  • large-scale, pragmatic, randomized clinical trial
  • trial design update
  • 1:1 randomization
  • intention-to-treat analyses
  • hierarchical testing

Study context

Population
Danish adults aged ≥60 years (2024/2025 season) and adults aged ≥18 years in Denmark and Galicia, Spain (2025/2026 season)Danish adults aged ≥60 years enrolled during the initial 2024/2025 season, planned sample size up to approximately 690,000 participants across both seasons
Participants
131,379 adults
Planned comparison
1:1 to RSV prefusion F (RSVpreF) vaccine or no vaccine
Primary endpoint
RSV-related respiratory tract disease hospitalization

No results yet. This paper sets out the design of a trial; its results are to come.

Further findings

Conduct of the study

Increase in the planned sample size to up to approximately 690,000 participants across both seasons
690,000
Following lower-than-expected event accrual and expansion of the EU indication to adults 18 years and older, the trial was extended to continue enrollment of adults aged ≥18 years across Denmark and Galicia, Spain during the 2025/2026 RSV season

Original publication

A pragmatic randomized trial to evaluate the vaccine effectiveness of bivalent RSV prefusion F vaccine for preventing RSV hospitalizations in adults (DAN-RSV): Trial design update. Am Heart J. Published 1 June 2026. doi:10.1016/j.ahj.2026.107497

Summarised from the published abstract; every number is checked against it