Health experts say Americans have built up less natural immunity against influenza because so few were infected in 2020. The comeback of common viruses including RSV brought toddlers, who were not exposed as babies, to U.S. hospitals with severe cases this year.

While a feared collision of infections remained at bay last winter, viruses will have more potential to spread this fall in venues opening up again. This has medical staff worried that flu and covid-19 admissions could surge together in the next few months.

By Ellen Francis | October 13, 202 | The Washington Post https://www.washingtonpost.com/health/2021/10/13/worst-cold-ever-covid-flu-season/?fbclid=IwAR2sPVWaYgMDnA_4i2myYiiAUgNlrkrGG7VagkWUyk-VPU9Fmm1QLc64doM