Alaska sets October-to-May RSV window; Native toddlers again qualify for a second dose

More Alaska babies now qualify for a second season of RSV protection. New state guidance published Monday adds children born preterm and children with Down syndrome to the list eligible for a second dose of nirsevimab, an antibody shot that protects infants against respiratory syncytial virus.

The state recommends giving the shot from October through May, when RSV circulates, though providers can go outside that window if the virus is still around or a child might not make it back in.

Alaska Native and American Indian children between 8 and 19 months old continue to qualify for the second dose, as they have since the 2024-25 season. So do children with cystic fibrosis and severe lung disease, chronic lung disease that needs medical support, or severe immune problems.

Nine Alaskans died last season with RSV as a contributing or underlying cause, including one child who wasn't eligible for the shot. Rural Alaska Native children have historically been hospitalized for RSV at five times the rate of other American children.

A study in the Yukon-Kuskokwim Delta found the shot cut RSV hospitalizations among infants by an estimated 89 percent in their first season, and cut illness serious enough to need care by 88 percent in the second. Research in other populations has found much weaker results for a second-season dose, and the state's bulletin doesn't directly address that gap — but it keeps the second-dose recommendation for Alaska Native children, and the American Academy of Pediatrics includes them too.

Parents shouldn't count on being flagged. The state's immunization registry doesn't automatically identify which children qualify for a second dose on risk grounds, so it's up to providers to catch it — and worth asking about directly. Nirsevimab is the only option for a second season, available through private insurance and through state and federal vaccine programs.