Editor's note: This story was most recently updated Feb. 21, 2020.

This year’s flu vaccine has been 45% effective against the flu so far this season, new CDC figures show.

It worked better against the B strain of the flu (50% effective) than the A strain (37% effective.) And overall it worked better in children and teens ages 6 months to 17, with a 55% effectiveness rate.

The effectiveness rate for vaccines typically ranges from 40% to 60%, the CDC says, and the vaccine can help prevent illness, hospitalization and death.

The news come as flu activity remains high.

After increasing for several weeks, the number of cases descreased slightly, the CDC says.

An A strain of flu remains more common now. Earlier in the season, a B strain was more common.

A B virus has been diganosed more among children and young adults up to 24 years old, while an A virus has been more common among adults 65 and older. Of the 105 pediatric deaths from flu, 72 are linked to the B virus.

Previously, officials had said this year's flu season was on track to be one of the worst in decades.

The agency estimates there have been at least 29 million flu illnesses, 280,000 hospitalizations and 16,000 deaths from flu so far this season.

Public health officials say that getting a flu shot can help protect against getting sick and getting hospitalized for flu.

The flu is a contagious disease, and it can cause mild to severe symptoms along with life-threatening complications, even in young, healthy children and adults. Since 2010, the flu has killed from 12,000 to 79,000 people annually in the U.S. and affected about 9.3 million to 49 million annually.

Here is what else to know about flu.