A71-10 Bivalent RSV Prefusion F Vaccine for Preventing RSV-Related and All-Cause Respiratory Hospitalizations According to Chronic Lung Disease Status: A Pre-Specified Analysis of the DAN-RSV Trial
L S Duus, M C H Lassen, N D Johansen, S H Christensen, N Aliabadi, K G Skaarup, D Modin, B L Claggett, C S Larsen, L Larsen, L Weise, M Dalager-Pedersen, M G Lindholm, A R Jensen, M Dons, K F Bernholm, F S Davidovski, C I Ottosen, A B Nielsen, J H Borchsenius, C Espersen, G Köse, F H Fussing, L Køber, S D Solomon, J S Jensen, C J Martel, B D Gessner, C Schwarz, E Gonzales, M Skovdal, P Zhang, E Begier, T Biering-SørensenAbstract
Background
Respiratory syncytial virus (RSV) is a major cause of hospitalization in older adults, especially among those with chronic lung disease. This prespecified DAN-RSV analysis evaluated RSVpreF vaccine effectiveness (VE) against RSV-related and all-cause hospitalizations in participants with and without chronic lung disease.
Methods
DAN-RSV was a pragmatic, open-label, randomized trial conducted during the 2024/2025 northern hemisphere winter. Adults ≥60 years were enrolled in November and December 2024 and randomized 1:1 to receive bivalent RSVpreF or no vaccine. Baseline and outcome data were obtained from nationwide health registries. Follow-up began 14 days after the booked study visit and continued until May 31, 2025. Chronic lung disease was defined by the presence of an ICD-10 code (A15-16, D860, E84, J42-47, J84, Z942) at baseline. The primary outcome was RSV-related respiratory tract disease (RTD) hospitalization. Secondary and exploratory endpoints included all-cause RTD hospitalization, all-cause lower RTD (LRTD) hospitalization, all-cause cardio-respiratory hospitalization, lab-confirmed RSV, and pneumonia hospitalization.
Results
Of 131,276 participants (65,642 randomized to RSVpreF and 65,634 to no vaccine), 9610 (7.3%) had pre-existing chronic lung disease. Participants with chronic lung disease were older (median age 70.4 vs 69.3 years), more often female (54% vs 49%), and had a higher comorbidity burden than those without chronic lung disease. Among participants in the no-vaccine group, incidence rates for all reported outcomes were higher among participants with chronic lung disease than those without (primary outcome: 2.5 vs. 0.51 events/1000 participant-years (PY)). RSVpreF consistently prevented the primary endpoint among those with pre-existing chronic lung disease (0.12 events/1000PY vs 0.51 events/1000PY; VE: 76.9% [95%CI: 42.9 to 95.8]) and those without (0 events/1000PY vs 2.50 events/1000PY; VE: 100% [95%CI: N/A due to no events in active arm]). Incidence rates of all other assessed endpoints were significantly lower in the RSVpreF group as compared with the no vaccine group, irrespective of chronic lung disease status (Figure).
Conclusions
Among adults aged ≥60 years, the bivalent RSVpreF vaccine reduced RSV-related and all-cause respiratory hospitalization outcomes irrespective of pre-existing chronic lung disease. The burden of RSV-related RTD hospitalization was approximately 5 times higher in persons with pre-existing chronic lung disease supporting existing GOLD recommendations to vaccinate this population of older adults against RSV.
Figure: Vaccine effectiveness of RSVpreF against RSV-related and all-cause respiratory outcomes according to pre-existing chronic lung disease at baseline*P-value for interaction not calculated due to no events in active arm of chronic lung disease strata
This abstract is funded by: DAN-RSV was funded by Pfizer Inc.