(NEXSTAR) – While COVID-19 spread is on the decline, the flu season is just getting started. New data released Friday by the Centers for Disease Control and Prevention show influenza activity ramping up in several U.S. states.

Last week, six “jurisdictions” (states or territories) had moderate or high flu activity, up from just two jurisdictions the week before.

The situation is most serious in Alaska, where flu activity is high. In Florida, Hawaii, New Mexico, Puerto Rico and Washington, D.C., flu activity is moderate, according to the CDC.

While the majority of states are showing “low” or “minimal” flu activity, things are expected to get worse before they get better. The exact timing of flu season varies year to year, but things typically start to worsen in October. The peak can come anytime in the winter, but is most often reached in February.

Flu levels are still considered low in Alabama, Arkansas, California, Colorado, Louisiana, Wyoming and South Carolina, but they all saw an increase in reported flu symptoms last week.

It’s also important to note the CDC map doesn’t capture all the flu activity happening in any given community. The data is based on the number of people reporting to a health care facility with flu symptoms – fever, plus a cough or sore throat. It is not based on lab-confirmed influenza cases.

That means it could be including cases that turn out to be other respiratory illnesses, but it also could be missing cases where people are staying home and fighting the sickness on their own.

CDC experts predict this year’s respiratory virus season will look a lot like last year. They expect the flu season, in particular, will be within the “typical range of severity.”

“However, even typical seasons vary widely in the number of illnesses, hospitalizations, and deaths,” reads the 2023-24 forecast.

Flu shots are already available in pharmacies and doctor’s offices, and can be received at the same time as a COVID-19 booster.