GSK plc has presented new real-world effectiveness data for its adjuvanted recombinant Respiratory Syncytial Virus (RSV) vaccine at RSVVW’26, the 9th Conference of the Respiratory Syncytial Virus Foundation in Rome, Italy. The company showcased 19 abstracts at the congress and supported three additional presentations, underscoring its ongoing research focus in RSV prevention.

A large retrospective cohort study conducted in the United States assessed the vaccine’s effectiveness in preventing RSV-related hospitalisation among adults aged 60 years and older. The study included more than 2.5 million individuals, of whom 520,440 vaccinated adults were matched 1:4 with over 2 million unvaccinated individuals.

Results showed that GSK’s RSV vaccine was associated with 75.6 percent effectiveness against RSV-related hospitalisation at a median follow-up of 5.6 months post-vaccination. The findings were based on observed reductions in hospital admissions during the 2023–24 RSV season.

Exploratory analyses further indicated an association with a 63.1 percent reduction in Major Adverse Cardiovascular Events (MACE), including heart attack and stroke, occurring during RSV-related hospitalisation. The study also reported vaccine effectiveness of 74.4 percent against severe chronic obstructive pulmonary disease (COPD) flare-ups and 61.6 percent against severe asthma exacerbations in the same setting.

In a separate nationwide cohort study conducted in Denmark among COPD patients aged 60 years and above, the vaccine was associated with 100 percent effectiveness in preventing RSV-related hospitalisations, although investigators noted wide confidence intervals due to sample size.

While observational studies cannot establish direct causality, the findings contribute to a growing body of evidence suggesting that RSV vaccination may reduce the risk of severe respiratory and cardiovascular outcomes in older adults.

The recombinant RSV vaccine, containing a prefusion RSV glycoprotein F (RSVPreF3) antigen combined with GSK’s AS01E adjuvant system, is approved in more than 65 countries for the prevention of RSV-related Lower Respiratory Tract Disease (LRTD) in adults aged 60 years and older.