ATLANTA, GEORGIA — This year's flu season has been one of the worst the U.S. has ever seen, and though it's winding down, we're not in the clear just yet.

According to the CDC, cases of the dominant and more serious influenza-A strain have been declining in recent weeks.

But another form of the virus, influenza-B, is on the rise, and now makes up for 60% of reported flu cases in the country.

Though generally milder, the B-strain virus tends to affect younger children more severely.

It's also possible for adults who have gotten sick from the A-strain to also become infected with the B virus within the same season.

Since both strains are still active, doctors recommend flu shots for those who are still unvaccinated. Standard hygiene practices should also be followed to keep the viruses at bay.