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.
GSK's shot won't reach that new patient population just yet.
Safety data in adults ages 50 to 59 was also consistent with data in adults 60 and above, according to GSK.
Regulatory agencies in Europe, Japan and other areas are currently reviewing GSK's application to expand Arexvy's approval to high-risk adults ages 50 to 59.
GSK's shot is approved in nearly 50 countries, a spokesperson for the company told CNBC.
Persons:
Phil Dormitzer, Dormitzer, Luke Miels, Arexvy, GSK's
Organizations:
Drug Administration, GSK, FDA, Centers for Disease Control, CNBC, CDC, Pfizer, Moderna, U.S
Locations:
British, Europe, Japan