A sharp drop in flu cases during COVID-19 pandemic

Precautions taken to fight the COVID-19 pandemic, including wearing masks and distancing, are likely the major reason for a steep decline of flu cases in the U.S., according to experts.

The Centers for Disease Control and Prevention (CDC) recently reported that it had logged 1,316 positive flu cases in its surveillance network between September 2020 and the end of January 2021. During that same period last year, the CDC had recorded nearly 130,000 cases.

Stephen Kissler, a research fellow in the Department of Immunology and Infectious Diseases at Harvard T.H. Chan School of Public Health, said in a February 11, 2021 Vox article that while more people received a flu vaccine this year, the sharp drop in cases was probably largely driven by mask-wearing and distancing. Kissler suggested that wearing masks in the future could be an effective way of helping control flu outbreaks. “Wearing masks in the wintertime, I think it’s something that might be here to stay,” he said.

Kissler also discussed how lower flu prevalence this year creates uncertainties about how the virus will evolve in the future. “We have no idea how obliterating the flu for an entire year affects its evolution,” he said. “We don’t know if it’s going to be easier to predict next year’s flu strain, because it hasn’t been spreading as much. Or if it’s going to be a lot harder, because it’s gone through this really tight…evolutionary bottleneck.”

Read the Vox article: We wiped out the flu this year. Could we do it again?