If you haven't had the flu this season, consider this your warning.
You aren't in the clear just yet.
The annual flu season — that oh-so-wonderful time of year that leaves millions sneezing, coughing and feeling lousy — is off to a late start, according to the U.S. Centers for Disease Control and Prevention.
But experts expect activity to pick up in coming weeks, especially given the recent cool snap.
"That might trigger more cases here," said Dr. Juan Dumois, chairman of the Division of Infectious Diseases at All Children's Hospital Johns Hopkins Medicine in St. Petersburg.
What's the weather got to do with the flu?
For one, cold, dry air makes the inner lining of the nose more susceptible to infection, Dumois said. In addition, chilly temperatures drive people indoors, where they are more likely to be exposed to the virus.
There is some good news: It isn't too late to get a flu shot.
Although the CDC recommends adults and children get vaccinated by October, flu shots will be available through March, Dumois said.
Even more good news: The flu shot is likely to be better than it was last year.
The vaccine offered during the 2014-15 season was only about 23 percent effective because one dominant strain of the flu mutated. Officials at the CDC say this year's shot is a much better match to the strains going around.
Flu season can start as early as October and last through May.
Between 5 and 20 percent of all Americans get the virus each year. About 200,000 are hospitalized.
Dumois says the vaccine is especially important for young children, adults over 60 and pregnant women.
"They have a much higher death rate (from the flu) than others," he said.
For everyone else, Dumois said, the shot is still a good investment.
"It is cost effective when you look at the hours lost from work either recovering from the flu or caring for a sick child," he said.
Flu vaccines tend to cost around $30 at retail pharmacies.
Contact Kathleen McGrory at firstname.lastname@example.org or (727) 893-8330. Follow @kmcgrory.