Sept. 29, 2021 — With the Delta variant of COVID-19 nonetheless raging in the USA and intensive care models in components of the nation crammed with sufferers with the coronavirus, specialists are voicing concern in regards to the added threat of a troublesome flu season.

Two mathematical fashions are predicting an enormous rebound within the quantity and severity of flu instances within the 2021-22 season after final yr’s flu season failed to indicate up when public well being measures introduced in to manage COVID-19 appeared to have the additional advantage of stopping the flu.

However each analyses, posted to the medRxiv preprint server and never but peer-reviewed by different specialists, have come to the identical conclusion: The flu might make a comeback this yr.

Within the worst-case situation, the U.S. might see an additional 300,000 to 400,000 hospitalizations from the flu — nearly double the standard quantity — in response to senior examine writer Mark Roberts, MD, director of the Public Well being Dynamics Laboratory on the College of Pittsburgh. These numbers could possibly be a catastrophe in areas the place hospitals are already crammed with COVID-19 sufferers.

Waning pure immunity within the public resulting from final yr’s lacking flu season might make folks, particularly younger youngsters, extra prone to get the virus.

“Normally, a mix of pure immunity and vaccination helps tamp down seasonal influenza,” says Roberts. “If we do not have the primary half, we’ll should rely extra on the vaccine.”

In a typical yr, about half of People get the flu shot. The brand new mathematical fashions predict that the vaccination fee would want to rise to about 75% to keep away from the additional hospitalizations. However even a ten% enhance in vaccination charges might scale back hospitalizations by 6% to 46%, relying on what strains are dominant.

Normally, the Southern Hemisphere flu season, from February to August, helps present what the Northern Hemisphere can count on over the approaching winter. However with strict COVID-19 measures and limits on worldwide journey nonetheless in place in international locations like Australia and New Zealand and far of South America, it has been one other file low yr for flu infections, says Ian Barr, PhD, deputy director of the World Well being Group’s Collaborating Middle for Reference and Analysis on Influenza in Melbourne, Australia.

Australia detected solely round 500 instances this yr, in contrast with about 300,000 in a standard yr, and recorded no hospitalizations or deaths from the flu. New Zealand recorded simply two instances.

“I’ve by no means seen something like this,” Barr says.

In Australia, the delicate flu season led to fewer folks getting their flu shot than typical. The speed fell from round 50% to only 33%, says Barr. “If that occurs within the U.S., the inhabitants will likely be much more susceptible as a result of there was nearly no flu for greater than 12 months,” he says.

Each Roberts and Barr say it’s important that as many individuals as potential get vaccinated through the upcoming flu season, particularly youngsters who may have nearly no pure immunity to the virus.

“The vaccine is our greatest weapon in opposition to the flu, particularly for probably the most at-risk teams,” says Barr.

Different components of the world had combined outcomes. India noticed a excessive variety of flu instances, whereas neighbouring Sri Lanka had only a few. West Africa additionally noticed fairly a excessive stage of circulating virus. General, the flu was detected in 45 international locations through the Southern Hemisphere season, lower than half of what may be anticipated in a standard yr, says Barr.

Regardless of the general low numbers, the WHO noticed sufficient within the information to make two changes to subsequent yr’s Southern Hemisphere vaccine formulation at its assembly on Sept. 24, after altering simply one of many strains for the Northern Hemisphere vaccine at its assembly final February.

The CDC recommends that everybody 6 months or older get the flu shot, with few exceptions.

WebMD Well being Information


MedRxiv: “Predicting the affect of low influenza exercise in 2020 on inhabitants immunity and future influenza season in the USA,” “Agent-based Investigation of the Impression of Low Charges of Influenza on Subsequent Season Influenza Infections.”

Mark Roberts, MD, director, Public Well being Dynamics Laboratory, College of Pittsburgh.

Ian Barr, PhD, deputy director, World Well being Group’s Collaborating Middle for Reference and Analysis on Influenza, Melbourne, Australia.

World Well being Group: “Really useful composition of influenza virus vaccines to be used within the 2022 southern hemisphere influenza season.”

CDC: “Ceaselessly Requested Influenza (Flu) Questions: 2021-2022 Season.”

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