Pitkin County epidemiologist warns of severe flu season, urges vaccination as measles risk grows nationally

Pitkin County epidemiology staff briefed the Board of Health on Jan. 15 about a relatively severe seasonal influenza A season, lowered RSV activity and growing measles activity nationally that could jeopardize the United States' official elimination status.

"This big push for flu A is really being driven by this very particular strain," said Carly (epidemiology), adding that the strain’s late emergence in the Southern Hemisphere means the current vaccine is a less-than-perfect match though still effective at preventing severe illness and hospitalization. She said wastewater concentrations and hospitalization indicators in Pitkin County show increased severity compared with recent years.

Carly also noted that recent state-level emergency hearings updated Colorado childhood vaccination recommendations and that Colorado is aligning recommendations with the American Academy of Pediatrics and other professional groups. On measles, she said national case counts have risen since a December 2025 outbreak and that officials are monitoring the potential loss of the U.S. elimination designation.

Board members and clinicians in the room reiterated standard preventive advice: get the seasonal influenza vaccine if not yet vaccinated, get MMR if not up to date, stay home when ill and consult a physician about antiviral treatments for high-risk patients. Hospital clinicians said they were seeing increased flu A cases and urged vaccination to prevent severe disease and hospitalizations.

The epidemiology team will continue wastewater monitoring and hospital surveillance and provide updates to the board.