Amid COVID-19 pandemic, flu has disappeared in the US

FILE - This Saturday, Oct. 17, 2020 file photo shows influenza vaccine syringes at the L.A. Care Health Plan and Blue Shield of California Promise Health Plan's Community Resource Center's Free Drive-Thru vaccination event in Los Angeles. February is usually the peak of flu season, with doctors' offices and hospitals packed with suffering patients. But not in 2021. Flu has virtually disappeared, with reports coming in at far lower levels than anything seen in decades. (AP Photo/Damian Dovarganes)
FILE - This Saturday, Oct. 17, 2020 file photo shows influenza vaccine syringes at the L.A. Care Health Plan and Blue Shield of California Promise Health Plan's Community Resource Center's Free Drive-Thru vaccination event in Los Angeles. February is usually the peak of flu season, with doctors' offices and hospitals packed with suffering patients. But not in 2021. Flu has virtually disappeared, with reports coming in at far lower levels than anything seen in decades. (AP Photo/Damian Dovarganes) (Copyright 2020 The Associated Press. All rights reserved)

NEW YORK – February is usually the peak of flu season, with doctors’ offices and hospitals packed with suffering patients. But not this year.

Flu has virtually disappeared from the U.S., with reports coming in at far lower levels than anything seen in decades.

Experts say that measures put in place to fend off the coronavirus — mask wearing, social distancing and virtual schooling — were a big factor in preventing a “twindemic” of flu and COVID-19. A push to get more people vaccinated against flu probably helped, too, as did fewer people traveling, they say.

Another possible explanation: The coronavirus has essentially muscled aside flu and other bugs that are more common in the fall and winter. Scientists don't fully understand the mechanism behind that, but it would be consistent with patterns seen when certain flu strains predominate over others, said Dr. Arnold Monto, a flu expert at the University of Michigan.

Nationally, “this is the lowest flu season we’ve had on record,” according to a surveillance system that is about 25 years old, said Lynnette Brammer of the U.S. Centers for Disease Control and Prevention.

Hospitals say the usual steady stream of flu-stricken patients never materialized.

At Maine Medical Center in Portland, the state's largest hospital, "I have seen zero documented flu cases this winter,” said Dr. Nate Mick, the head of the emergency department.

Ditto in Oregon's capital city, where the outpatient respiratory clinics affiliated with Salem Hospital have not seen any confirmed flu cases.