FRIDAY, March 18, 2016 (HealthDay News) -- This flu season continues to be the mildest in the past three years, U.S. health officials say.
But flu is still cropping up in new areas of the country, and flu season isn't over yet, the experts cautioned.
In most years, flu season peaks in February or early March, but as of this week, flu is still spreading and the peak is not in sight yet, according to Lynnette Brammer, an epidemiologist with the U.S. Centers for Disease Control and Prevention's influenza division.
"Flu activity is still going up," she said. "It's going to be a later peak." Brammer is still expecting the season to peak in March, but it could linger on until April.
On the plus side, this year's flu vaccine is a good match for the circulating flu viruses. The vaccine is about 59 percent effective this year, the CDC said. That's much better than last year when the vaccine didn't contain the most common circulating virus, according to the CDC.
"This means that getting a flu vaccine this season reduced the risk of having to go to the doctor because of flu by nearly 60 percent," Dr. Joseph Bresee, chief of CDC's Epidemiology and Prevention Branch, said in a statement. "It's good news and underscores the importance and the benefit of both annual and ongoing vaccination efforts this season."
Since the season hasn't peaked, Brammer is still advising people who haven't had a flu shot to get one. "There is still value to getting vaccinated," she said.
This flu season is a welcome change from last year, which saw a particularly early and nasty flu season. By this time last year, flu was already severe and sending thousands of Americans -- especially older ones -- to the hospital, Brammer said. In fact, she added, "By this time last year, we had peaked and were coming down."
Despite this year's mild season, 20 children have died from flu complications so far, Brammer said. Depending on the severity of a flu season, the CDC has reported anywhere from 40 to more than 300 deaths in babies and children. So, the number of deaths in children this year is comparatively low, she said.
Unlike last year, the most common flu strain circulating this season is the H1N1 strain. Last year, it was the H3N2 strain, Brammer said. "But H3N2 is still hanging in there, it's not going away," she said. "We've got a little bit of everything out there."
Both of these strains, and a third one, are included in the current flu vaccine, Brammer said, making this year's shot a better match than last year's vaccine. Last year, the flu vaccine was only 23 percent effective overall, according to the CDC.
Milder weather may be one factor affecting this flu season, Brammer said. But it's only one factor of many that can determine the severity of a flu season. Another big factor is how many people are immune because they've been vaccinated.
Flu activity is widespread throughout most of the country. However, in the Southwest it appears to have peaked and may be declining, Brammer said.
In a typical season, flu complications -- including pneumonia -- send more than 200,000 Americans to the hospital. Death rates linked to flu vary annually, but have gone as high as 49,000 in a year, the CDC said.
Virtually everyone older than 6 months of age is advised to get a flu shot. Exceptions include people with life-threatening allergies to the flu vaccine or any ingredient in the vaccine, according to the CDC.
Pregnant women are considered at high risk and should get vaccinated. Women with newborns also need their flu shot to help protect their infants, who can't be vaccinated until they are at least 6 months old. Also considered at high risk for flu and prime candidates for a vaccine are seniors and people with chronic health problems, such as lung and heart disease, the CDC said.
For more information on flu, visit the U.S. Centers for Disease Control and Prevention.