Flu season is arriving sooner than usual, and experts urge vaccination now

The influenza season is getting underway earlier than expected this year, with experts saying flu cases started appearing on the West Coast in September.

Ryan Malosh, who leads the Immunization Division at the Michigan Department of Health and Human Services, said emergency room visits for flu-like illness are beginning to rise in Michigan. He said anyone who still has not received a flu shot should get one as soon as possible.

He noted that the flu vaccine takes roughly two weeks to build antibody protection in the body.

“When cases are really spiking, the last thing you want to do is be caught without its protection, so it is definitely a good time to get it,” Malosh said.

While the vaccine does not always prevent infection, it can greatly lessen how severe the illness becomes and how long it lasts, and it also lowers the chances of hospitalization and death.

Children remain one of the groups most at risk from the flu. In the 2025-26 influenza season, more than 1,600 children in Michigan were hospitalized because of flu, and 13 children died, according to state health department data.

Pregnant women, older adults and people with immune system disorders are also especially vulnerable. Even healthy adults, however, can become seriously ill from influenza.

Dr. Adam Lauring, chief of infectious diseases at Michigan Medicine, said updating the vaccine to match circulating variants is difficult each year. This season’s vaccine does include the H1N1 strain most commonly circulating, but early reports suggest the virus may have mutated in a way that could make the shot less effective, particularly for younger people.

“We don't know yet,” Lauring said. “We won't know until later in the season. But I think the message still is, go out and get your vaccine.”