Each flu season is different and it’s hard to compare one to another, but Jernigan said this season seems a little less severe than the 2014-2015 flu season. Several flu strains circulate in any given season and this year, H3N2, H1N1 and two strains of influenza B are circulating.
Right now, H3N2 is the most common strain in the U.S. Flu strains mutate a little constantly but the H3N2 now spreading is not a new mutant, the CDC said. The current vaccines on the market protect against all four of the most common strains.
“While flu vaccines are far from perfect, they are the best way to prevent getting sick from the flu,” CDC director Dr. Brenda Fitzgerald said.
So far, it looks like the current vaccines on the market provide about 30 percent protection from H3N2 flu, the CDC said. But better estimates of how well the vaccine has been working won’t be available until February.
It’s not too late to get a flu vaccine, the CDC said, and there should still be plenty of vaccine supply. Sometimes there are second and even third waves of flu, so a state that’s been hit hard by H3N2 might see a fresh wave of H1N1 flu later and then influenza B may pass through even later.
“In general, we see things peaking right about now,” Jernigan said.
“Even if we have hit the top of the curve or the peak, it still means we have a lot more flu to go.”
And certain people should seek immediate treatment if they think they might have flu. That includes people over 65, children under 5 and people with conditions such as asthma or diabetes.
If someone has any trouble breathing, they should seek immediate emergency care.
Three drugs on the market are effective against flu: oseltamivir or Tamiflu; zanamivir or Relenza; and peramivir. There are also generic versions of the name-brand drugs, Jernigan noted. They are not cures but if given immediately can make a bout of flu less intense.
National supplies are adequate but there could be spot shortages, the CDC said. Jernigan recommended calling ahead to a pharmacy before trying to fill a flu drug prescription to make sure it's on hand.
Maggie Fox is a senior writer for NBC News and TODAY, covering health policy, science, medical treatments and disease.