Top U.S. official urges caution with RSV, vaccine in development

WASHINGTON (Reuters) -U.S. officials are working on a respiratory syncytial virus (RSV) vaccine, but until one is available people should exercise caution, especially seniors and parents of young children, the nation's top infectious disease official said.

A vaccine for the infectious respiratory disease will hopefully come within the next year or two, National Institute of Allergy and Infectious Diseases Director Dr. Anthony Fauci told MSNBC in an interview.

RSV is not a new virus but rising infections among young children are reportedly filling some U.S. hospitals to capacity at the same time as an earlier-than-normal influenza season and rising COVID cases are raising concerns about a "tripledemic" this winter.

"We are working very, very intensively in trying to develop one as quickly as possible," Fauci said.

Data from early studies look promising, "and we're hoping in the next year to two, but it's not going to be this season," he said, adding that officials were urging vulnerable populations to get their flu and COVID boosters to help offer some protection against a triple-whammy.

RSV is not a new virus but it is a leading cause of pneumonia in toddlers and the elderly and can lead to hospitalization or death. The virus' complex molecular structure and safety concerns have stymied efforts to develop a vaccine, although drugmakers such as GlaxoSmithKline Plc and Pfizer Inc are pursuing candidates.

While there is a higher concentration of RSV impacting U.S. children at the moment, it can also be a serious disease for older adults, he added.

"If you're an elderly person, you are vulnerable to the serious consequences of RSV," Fauci told MSNBC.

(Reporting by Susan Heavey; editing by Rami Ayyub and Aurora Ellis)