By KENDRA MANN, WJLA
The A strain had previously dominated this flu season, but now the CDC says parents need to remain vigilant of the B strain -- especially those with younger children.
"We know that illness associated with influenza B can be just as severe as illness associated with influenza A," CDC spokeswoman Kirsten Nordlund told CNN. "We also know that influenza B tends to be more severe for younger children."
The CDC says 58 percent of recent reports for the week ending March 17 were from the B strain, not the A strain.
Officials add that just because you have had the flu this season doesn't mean you're in the clear; it's possible to get sick with a different strain in the same season.
The CDC recommends anyone who hasn't gotten their flu shot yet to do so now.