FDA approves GSK's RSV vaccine for high-risk adults ages 50 to 59, expanding shot's reach

The Food and Drug Administration on Friday expanded the approval of GSK's respiratory syncytial virus vaccine to adults ages 50 to 59 who are at increased risk of getting severely sick from the potentially lethal virus. 

The shot, called Arexvy, is the first vaccine cleared by the FDA to protect that population from RSV. The agency first approved GSK's jab in May 2023 for patients 60 and above, who are more vulnerable to severe cases of the virus. 

RSV causes thousands of hospitalizations and deaths among seniors each year, according to data from the Centers for Disease Control and Prevention. But the virus can also cause severe illness in adults 50 and up — or even younger — with underlying chronic conditions such as asthma, diabetes and congestive heart failure.

About 13 million Americans ages 50 to 59 are at high risk of severe illness from RSV, said Phil Dormitzer, GSK's head of vaccines research and development and infectious disease research, in an interview. 

"It's useful both because, of course, you can meet the medical needs of that age group," Dormitzer told CNBC, "but it's also nice for pharmacists to have a single vaccine that they can administer to a wider population, so that provides simplicity."

GSK's shot won't reach that new patient population just yet. An advisory panel to the CDC will vote later in June on recommendations for GSK's vaccine, along with a rival shot from Pfizer and a newly approved jab from Moderna. 

The FDA's expanded approval could help GSK maintain its dominance in the RSV market later this fall and winter, when the virus typically spreads more widely in the U.S. The British drugmaker's shot booked around £1.2 billion in sales last year, outpacing the $890 million (about £699 million)in