A ‘Tripledemic’? Flu and Other Infections Return as Covid Cases Rise

For more than two years, shuttered schools and offices, social distancing and masks granted Americans a reprieve from flu and most other respiratory infections. This winter is likely to be different.With few to no restrictions in place and travel and socializing back in full swing, an expected winter rise in Covid cases appears poised to collide with a resurgent influenza season, causing a “twindemic” — or even a “tripledemic,” with a third pathogen, respiratory syncytial virus, or R.S.V., in the mix.Cases of flu have begun to tick up earlier than usual, and are expected to soar over the coming weeks. Children infected with R.S.V. (which has similar symptoms to flu and Covid), rhinoviruses and enteroviruses are already straining pediatric hospitals in several states.We’re seeing everything come back with a vengeance,” said Dr. Alpana Waghmare, an infectious diseases expert at Fred Hutchinson Cancer Center and a physician at Seattle Children’s Hospital.

Most cases of Covid, flu and R.S.V. are likely to be mild, but together they may sicken millions of Americans and swamp hospitals, public health experts warned.

“You’ve got this waning Covid immunity, coinciding with the impact of the flu coming along here, and R.S.V.,” said Andrew Read, an evolutionary microbiologist at Penn State University. “We’re in uncharted territory here.”

The vaccines for Covid and flu, while they may not prevent infection, still offer the best protection against severe illness and death, experts said. They urged everyone, and especially those at high risk, to get their shots as soon as possible.

Older adults, immunocompromised people and pregnant women are most at risk, and young children are highly susceptible to

influenza and R.S.V. Many infected children are becoming severely ill because they have little immunity, either because it has waned or because they were not exposed to these viruses before the pandemic.

R.S.V. causes about 14,000 deaths among adults 65 and older and up to 300 deaths among children under 5 each year. No vaccine is available, but at least two candidates are in late-stage clinical trials and appear to be highly effective in older adults. Pfizer is also developing an antiviral drug.