We’ve had 25 million flu cases in 2023. Will we see a second wave?

As of Feb. 24, Atlanta’s Centers for Disease Control and Prevention (CDC) estimated 25 million illnesses, 280,000 hospitalizations and 18,000 deaths from the flu this season. With that in mind, the CDC also reported that influenza activity is low nationwide as of Feb. 18. The virus certainly made an impact this year, but cases are now dwindling.

According to Michael Osterholm, PhD, director of the Center for Infectious Disease Research and Policy at the University of Minnesota in Minneapolis, a second wave of flu cases is still possible for 2023 but not expected.

“It’s not unusual to see an influenza B resurgence after the big A peak, but we’ve really seen no evidence of that so far,” Dr. Osterholm told Becker’s Hospital Review.

CDC domestic influenza surveillance team leader Alicia Budd added that “whether activity will increase again just cannot be predicted.”

According to the CDC’s flu forecast, which predicts upcoming flu cases across the country, the U.S. should expect somewhere from a couple hundred to a few thousands new flu cases by the end of this week.

“This week’s ensemble predicts that the number of new weekly confirmed influenza hospital admissions will remain stable or have an uncertain trend nationally, with 240 to 3,400 new confirmed influenza hospital admissions likely reported in the week ending March 4, 2023,” the CDC reported.

The CDC places much of the health care industry’s success at battling the flu this year on the effectiveness of this season’s vaccines.

“According to data from the New Vaccine Surveillance Network (NVSN), VE against the predominant H3N2 viruses was 45% among children, which is higher than seen previously for this virus,” a Feb. 2023 CDC report explained. “To compare, during previous seasons, VE against H3N2 has been around 30%. The higher VE this season is likely because flu vaccination elicited good immunity against the variety of viruses circulating. Flu vaccine effectiveness against circulating influenza A(H1N1) viruses was 56%.”

The CDC continues to recommend that everyone six months old or older get an annual flu vaccine, as “the majority of influenza viruses tested are in the same genetic subclade as and antigenically similar to the influenza viruses included in this season’s influenza vaccine.”