Adrianna Rodriguez | USA TODAY
Flu shot: When to get the vaccine during coronavirus pandemic
Public health experts say this year everyone should get a flu shot, if possible.
As COVID-19 raged last year, the seasonal flu all but vanished, according to data from the U.S. Centers for Disease Control and Prevention.
During the 2019 flu season from Sept. 29 to Dec. 28, the CDC reported more than 65,000 cases of influenza nationwide. During the same period last year, the agency reported 1,016 cases.
Health experts said that high vaccination rates against the flu – combined with social distancing, mask-wearing and hand-washing employed to stop the spread of the coronavirus – played a huge role in preventing influenza transmission.
The significant drop occurred despite a six-fold increase in testing at public health labs, most of which checked for influenza A and B along with COVID-19.
Clinical lab testing was slightly lower during the last quarter of 2020 as physicians ordered fewer flu tests because less of the illness was circulating.
“The public health labs test for more surveillance purposes rather than patient care reasons and are therefore a better measure of influenza burden each season than clinical labs,” CDC spokesperson Kate Grusich told USA TODAY.
While many experts are relieved to see public health measures working against flu spread, they also say it speaks volumes about the transmissibility of COVID-19.
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“It says that it’s more contagious and that it’s less forgiving of any lapses of these types of prevention measures,” said Dr. David Hooper, chief of the infection control unit at Massachusetts General Hospital.
Hooper said one reason the coronavirus is more transmissible is because people can shed the coronavirus days before exhibiting any symptoms, if they develop symptoms at all.
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People generally don’t shed flu virus for more than a day before symptoms appear, Hooper said.
Dr. Susan Rehm, vice chair at the Cleveland Clinic’s department of infectious diseases, said another reason flu incidences are low this year is because most people have some innate immunity from prior vaccinations and infections.
“COVID is a novel infection caused by the SARS coronavirus and no one has any innate immunity to it,” she said. “So, the population is probably overall more susceptible to it than maybe to influenza.”
It also helps that Americans have been vaccinating against the flu at record numbers this year compared to previous seasons, Rehm added.
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As of Dec. 25, more than 192 million doses of flu vaccine have been distributed, “which is the highest number of doses distributed in the U.S. in a single flu season,” the CDC’s Grusich said. Flu vaccine manufacturers project they will provide as many as 194 to 198 million doses to the U.S. market by the end of the season, which could last as late as May, according to the CDC.
Rehm said Americans were especially motivated to get a flu vaccine this year as health experts warned hospitals could be overwhelmed by both flu and COVID-19 patients in a possible “twindemic” scenario.
“A lot of people in the past haven’t felt that flu was very severe and thus haven’t necessarily felt so motivated to get vaccinated,” she said. “Certainly, COVID has taught us that respiratory illnesses can be extremely severe.”
While the news about flu is good so far, Rehm cautioned the season is not over yet.
“Just because it’s been low so far doesn’t prove that it’s going to be low going forward and getting vaccinated is the best thing you can do to prevent influenza,” she said. “It’s not too late to get vaccinated for influenza.”
Follow Adrianna Rodriguez on Twitter: @AdriannaUSAT.
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