Seasonal fall flu

The past two flu seasons have been milder than usual, with low numbers of cases and few hospitalizations and deaths. Experts attribute the decline to COVID-19 precautions such as wearing face masks and social distancing. People were also traveling less during the height of the pandemic.

“Now that people are out and about without masks, traveling extensively, and once again having vacations, going to restaurants and religious services, and back to school and to the office, there are more opportunities for the [flu] virus to circulate,” says William Schaffner, medical director of the National Foundation for Infectious Diseases and a professor of infectious diseases at the Vanderbilt University Medical Center in Nashville, Tennessee.

Americans also have less natural immunity to influenza because so few people were infected in 2020 and 2021, Pekosz says.

In typical years, “a good percentage of the population gets infected with influenza, and their immunity after infection lasts longer than what we get from vaccination,” Pekosz notes. “What we’re seeing is a couple of years where we didn’t see infection. So more people may be susceptible to influenza in this coming season.”

He says an early season is usually a sign of more susceptible people in a population. That would explain what happened in Australia — and possibly predict an early season here.