Cases of influenza are rising as the holiday season begins. New CDC figures show an 8% increase in people testing positive for flu in the week ending Dec. 6 and a 3% rise in health-care visits for respiratory illnesses.
CBS News medical contributor Dr. Céline Gounder, editor-at-large for public health at KFF Health News, says the dominant strain this season is H3N2. Seasonal flu vaccines are formulated to target the strains expected to circulate—typically three strains—and they remain effective. The shot offers strong protection for children and moderate protection for adults against hospitalization. Most importantly, vaccination is an important layer of defense against the worst outcomes, including hospitalization and death, particularly for very young children and older adults.
Some outlets have labeled this season’s H3N2 a “super flu” because of mutations it has acquired. Dr. Gounder explains those changes can make the virus somewhat more resistant to existing immunity and to vaccine protection, but not in a way that indicates a pandemic is likely. While vaccines may be less effective against H3N2 than against other strains, international data (for example from England) show they still provide substantial protection against severe disease. That means vaccinated people might still become infected, but they are much less likely to require hospitalization.
Dr. Gounder emphasized a key point people sometimes forget: the flu shot’s main benefit is reducing severe illness, not guaranteeing you won’t get any infection at all.
She also discussed recent reporting about the FDA possibly adding black-box warnings to COVID-19 vaccines. A black-box warning is the agency’s most serious label. An internal FDA memo reportedly suggested up to 10 children might have died after COVID vaccination; after review that estimate was revised to between zero and seven possible deaths. To put that in context, more than 2,100 children died from COVID overall. As with any medical intervention, there is a trade-off between risks and benefits, and some of the scrutiny stems from retrospective review of pandemic-era decisions with political overtones.
Bottom line: flu activity is increasing, H3N2 is dominant and carries mutations that may reduce but do not eliminate vaccine protection. Getting the seasonal flu vaccine remains an important step to lower the risk of severe illness, hospitalization, and death.