Last week, the Mississippi State Department of Health reported the second pediatric flu death this season.
Commissioner Scott Gottlieb said the FDA is partnering with other health agencies to look at millions of flu cases; they want to understand why the 2017-18 vaccine was only 25 percent effective overall against the influenza A strain.
Fewer visits to the doctor for the flu may indicate that the season is winding down, but state health officials are not ready to declare the worst is over, just yet.
In a statement, he said an analysis of the data is still underway, but it may have some clues on effectiveness of cell-based and egg-based vaccines and may shed light on effectiveness of high-dose and adjuvanted version of the vaccines in seniors, as compared to standard flu vaccine.
Influenza A (H3N2), has been the most prevalent flu virus in the United States this year.
Citing data provided by the Centers for Disease Control, Kao said that about 36,000 cases of flu-like illness were reported during the Lunar New Year holiday, and some of those who had serious complications were young or middle-aged people. The flu shot wasn't particularly effective this year because one of the strains making people sick is hard to prevent using the vaccine, but experts say it's better than nothing.
It's "not too late to get vaccinated if you have not yet done so, given that we are starting to see a larger proportion of illnesses caused by H1N1 and B influenza, for which vaccines offer better protection", Gottlieb said.
So why did this season's vaccines not deliver higher protection against H3N2?
Independent experts are cheering the return of the nasal vaccine for the next flu season because of its potential to increase the vaccination rate among children.
The nasty flu season has brought more attention to the flu shot. "Maybe the key thing is a virus can hurt you if it's quite different than what your immune system imprinted on that very first time you saw influenza as a kid".
"The knowledge we gain through such scientific research will allow us to determine if we need to change recommendations to vaccine manufacturers for how future seasons' vaccines should be produced", Gottlieb said.
In the meantime, this flu season isn't over yet, though CDC data shows a decline in visits to doctor's offices and outpatient clinics.
According to the Arizona Department of Health, there have been more than 3,000 reported cases of H3N2, the most out of all viruses this year. The WHO recommends vaccination for global travelers for 21 Brazilian states, and the group is closely monitoring for signs that new areas are at risk.
And researchers are working to make a better flu shot, said Meda Higa, assistant professor of biology at York College.