GSK RSV Shot 43% Effective Against Severe Disease in Third Year

(Reuters) – GSK said on Tuesday that its Arexvy respiratory syncytial virus vaccine was 43.3% effective in preventing severe illness in its third season after patients received the shot.

That compares with 94.1% effectiveness in preventing severe RSV in the first season and 64.2% a year later, according to data from GSK’s Phase 3 clinical trial. The trial initially enrolled about 25,000 volunteers in 17 countries.

Arexvy is one of three RSV vaccines approved for use, alongside shots made by Pfizer and Moderna, with GSK’s shot so far dominating the market.

In the U.S., the vaccines are currently recommended as a one-time shot for adults aged 75 and older, and for those ages 60 to 74 who are at higher risk of severe illness due to health conditions or other factors.

“We are excited by these new data which show that a single dose of Arexvy could help protect millions of older adults at risk of RSV disease over three seasons to benefit public health,” Tony Wood, GSK’s chief scientific officer said in a statement.

GSK said it was continuing to supply data to regulators to help them determine if or how often patients should be re-vaccinated.

RSV typically causes cold-like symptoms but is also a leading cause of pneumonia in toddlers and older adults, leading to 177,000 hospitalizations and 14,000 deaths in the United States annually.

(Reporting by Michael Erman; Editing by Bill Berkrot)