Public health experts say that, while it has been a relatively mild flu season, it’s not over yet – and a new strain could be partially to blame.
While influenza normally peaks in the dead of winter, a second peak is emerging nationally.
“So this is a little late for that second peak but usually that second streak is related to influenza B strain,” said Dr. Rachel Rubin, senior medical officer for the Cook County Department of Public Health.
Recent data indicates flu activity is still high in several locations. According to the CDC, the flu remains widespread in 46 states, including Illinois. That number is down from the 48 states last week.
Still, health experts say it has been a relatively mild influenza season so far, something the CDC attributes to an effective flu vaccine. This year’s shot was 47 percent effective against the most prevalent strain and 60 percent effective in children ages 6 months to 17 years old.
“We’re never 100 percent sure how good of a match the vaccine is because we can never predict with 100 percent certainty how the flu virus is going to mutate,” said Rubin.
But the latest increase in reports of flu-related illnesses could be due to a second, more potent, virus known as Type A H3N2, experts believe.
“H3N2 is a more virulent strain and people who get H3N2 may end up getting more sick than with the more predominant H1N1 this year,” Rubin said.
It's not unusual for several flu strains to spread around the country at the same time, but one kind usually predominates.
Earlier this month, about 60 percent of the flu virus samples tested were the more troublesome H3N2 strain.
Uncertainty about what kind of H3N2 will be spreading later this year recently led the World Health Organization to postpone its decision on which strains should go into the flu vaccine for next season.
So far, 69 children have died from flu-related complications this season, including at three in Illinois.
CDC officials estimate there have been somewhere around 20,000 to 30,000 flu-related deaths so far this winter. They also think there have been around 300,000 flu-related hospitalizations and around 25 million flu illnesses.
Last season, an estimated 80,000 Americans died of flu and its complications, the disease's highest death toll in at least four decades. In recent years, flu-related deaths have ranged from about 12,000 to 56,000, according to the CDC.
Experts say it’s not too late to get vaccinated.
“The vaccine, even though we can’t say exactly how effective it’s going to be it will help prevent H2N3,” Rubin said.
To find a location to get a flu vaccine near you, click here.