Shots are urged as RSV hits the U.S.

The highly contagious respiratory virus is sending toddlers and babies to the hospital.

- BY RONG-GONG LIN II

RSV is the leading cause of U.S. infant hospitalization and presents particular risk for the youngest babies.

(FRANCINE ORR Los Angeles Times)

A wave of the highly contagious respiratory syncytial virus is sweeping across the United States — sending greater numbers of babies and toddlers to the hospital, recent data show.

The onset of RSV comes as the country heads into the wider fall-and-winter respiratory virus season, also typically marked by increased circulation of ailments such as COVID-19 and the flu.

But RSV, the leading cause of infant hospitalization nationwide, presents particular risk for the youngest babies, a major reason health experts recommend pregnant women either get vaccinated near their delivery date or immunize their newborns.

“This is the perfect time to get your vaccine for RSV if you have never gotten one,” the Los Angeles County Department of Public Health said in a statement to The Times.

RSV can spread through coughs or sneezes but also by touching a contaminated surface, such as a door handle, and then touching your face before washing your hands, health officials warn.

For the week ending Oct. 11, about 1.2% of emergency room visits nationwide among infants younger than 1 were due to RSV—up from 0.4% a month earlier, according to data posted by PopHIVE, a project led by the Yale School of Public Health.

“An RSV wave is starting to take hold,” epidemiologists Katelyn Jetelina and Hannah Totte wrote in the blog Your Local Epidemiologist.

RSV can be dangerous for infants, older adults and people with certain medical conditions, according to the U.S. Centers for Disease Control and Prevention.

RSV can cause pneumonia, as well as a severe inflammation of the lungs' small airways, known as bronchiolitis, the California Department of Public Health said.