A Pragmatic Randomized Trial to Evaluate the Vaccine Effectiveness of Bivalent RSV Prefusion F Vaccine (Abrysvo) for Preventing RSV Hospitalizations in Adults

doi:10.1056/evidoa2600272

DAN-RSV

Patient / Population Intervention / Exposure Comparison Outcome

In 511,535 adults aged 18 years or over in Denmark and Galicia, a single dose of RSVpreF vaccine reduced hospitalisation for RSV-related respiratory disease compared with no vaccine.

N

511,535patients

Design

Pragmatic, registry-based, open-label, individually randomised trial, 1:1 RSVpreF vs no RSV vaccine; recruitment by nationwide electronic invitation with remote e-consent, baseline and outcome data from national health registries; outcomes counted from 14 days after vaccination through the RSV season (up to 8 months), with subsequent-season outcomes prespecified

Endpoint

Hospitalisation for RSV-related respiratory tract disease

Relevance

2Important — one of several pillars.

ResultIn the expanded cohort of 511,535 adults aged 18 or over in Denmark and Galicia, hospitalisation for RSV-related respiratory tract disease occurred in 19 vs 64 (vaccine effectiveness 70.3%, 95% CI 49.7-83.2). RSV-related cardiorespiratory hospitalisation 20 vs 67 (VE 70.0%, 50.1-82.8); any cardiorespiratory hospitalisation 2,704 vs 2,889 (VE 6.2%, 1.2-11.1). All-cause hospitalisation and death were unchanged. In the original Danish cohort aged 60 or over, protection held into a second season (7 vs 16 events; VE 56.2%, -12.4 to 84.8; both seasons combined 10 vs 34, VE 70.6%, 39.1-87.0). Serious adverse events 2.0% vs 2.2%; Guillain-Barre syndrome in 5 vaccinated and none in the control group.

Biering-Sorensen T, Lassen MCH, et al. Presented at ESC Congress 2026, Hot Line 2, 29 August; simultaneously published in NEJM Evidence. 10.1056/evidoa2600272

Discussion & critique

A pragmatic registry trial half a million people wide, and the RSV-specific effect is unambiguous: about 70% fewer RSV hospitalisations, holding into a second season and across ages 18 and up. The cardiovascular claim is the softer one — any cardiorespiratory hospitalisation fell by 6.2%, an interval that only just clears zero, and all-cause hospitalisation and mortality did not move. Nineteen events against 64 is a large relative effect on a small absolute base: roughly 1,800 people vaccinated to prevent one RSV hospitalisation. Five cases of Guillain-Barre syndrome against none deserve naming, small numbers notwithstanding.