Is Flu Season Over Yet?

The number of flu cases in the United States has sharply declined since the peak of the season hit in February—but we're not out of the woods yet.

While there are significantly fewer cases being reported now, strains of the flu are still making the rounds.

"We don't usually declare the end of the flu season," Centers for Disease Control and Prevention spokesperson Kristen Nordlund told Newsweek.

The CDC continues to monitor flu cases year-round, even through the summer, she said, because the flu is never officially not active. The most recent surveillance report on flu activity was published about week 12 of the flu season, which covered the days of March 18 to 24, during which flu activity overall decreased.

While the activity as a whole decreased, cases of influenza B were more popular than influenza A, which was not the case for most of the 2017-2018 flu season. The flu vaccine loses its effectiveness the more time passes after it is administered to patients, but usually, the vaccine lasts the season, according to the CDC.

While it's not fair to say flu season is over, the height of it is. Each year the start of flu season varies a bit, but in 2017, it started in early November. Activity then rose in December, January and February before it peaked. Generally, the peak happens sometime between December and February, according to the CDC.

The CDC is set to update statistics on the flu season on Friday morning. That update will include information about whether or not the number of cases has dropped even more since March. The 2017-2018 flu season was one of the most deadly and severe in recent years with a total of 137 infant deaths so far. Hundreds of thousands of people were hospitalized during the 2014-2015 flu season, a number one expert expected this recent season to rival, the New York Times reported.

patient getting flu shot
This deadly flu season isn't over yet. A patient shown here prepares to get a flu shot in a Walgreen pharmacy, January 22, 2018. Justin Sullivan/Getty Images