Teamsters Local 848 truck driver Carlos Gonzalez sits to be tested for COVID-19 at a testing site provided by the International Brotherhood of Teamsters in Long Beach, California, US, on July 16, 2020. [Photo/Agencies]
Public health experts, researchers and manufacturers warn the coming flu season could bring a “double-barrel” respiratory disease outbreak in the United States, just as fall and winter are expected to exacerbate the spread of Covid-19.
At the same time, researchers said the strategies currently used to prevent Covid-19 transmission – namely, hand-washing, mask-wearing and social distancing – could also help lessen flu outbreaks, if Americans are willing to practice them.
“We will be faced with basically a double-barrel respiratory virus season, both influenza and Covid,” said Dr William Schaffner, medical director for the National Foundation for Infectious Diseases and a professor of medicine at the Vanderbilt University School of Medicine in Tennessee.
Flu season typically peaks between December and February in the northern hemisphere. It caused an estimated 61,000 deaths and 810,000 hospitalizations in 2019 in the US, according to the US Centers for Disease Control and Prevention (CDC).
By comparison, Covid-19 has killed more than 166,000 people in the US with months to go before the end of the year, according to the Johns Hopkins University Coronavirus Resource Center. The disease hospitalized an estimated 293,000 people just between March and May 2020, according to the healthcare consulting firm Avalere. Those deaths and infections also occurred despite huge efforts – such as shutting down large parts of the US economy – being put into action to slow the virus’s path.
While the flu’s seasonality is not clearly understood, the way it spreads is well documented. Flu is transmitted in much the same way Covid-19 spreads: coughs, sputters and sneezes in close proximity in closed spaces and in crowds. For those reasons, social distancing measures are effective against influenza as well as Covid-19.
When community spread of Covid-19 began in the United States in March, widespread shutdowns shaved “four to six weeks” off the flu season in 2020, said Dr Richard Kennedy, co-director of the Mayo Clinic’s vaccine research lab.
That was “probably as a direct result of the social distancing and the mask-wearing and the shutdown,” said Kennedy. A similar phenomenon is taking place in the southern hemisphere, where winter flu season is now tapering off. Countries such as Chile have seen historically low influenza transmission.
“Will we see that same thing up here? The answer is, if we wear our masks and social distancing, yes. If we remain shut down, yes,” said Kennedy. “But I don’t know if Americans are going to do any or all of the above.”
“We’re seeing groups wanting to open the economy up regardless of the risks. Then we’re seeing people saying, ‘No, we want to shut down and we don’t care if the economy crashes,’” said Kennedy.
A woman holds a small bottle labeled with a "Vaccine COVID-19" sticker and a medical syringe in this illustration taken on April 10, 2020. [Photo/Agencies]
But unlike for Covid-19, the world has another tool to fight seasonal influenza: flu vaccines.
Young and old alike have fallen behind on routine vaccinations due to the pandemic. GlaxoSmithKline reported one of its vaccines, called the zoster for adult shingles, experienced a 67% drop in sales in April and May of 2020.
A severe flu outbreak would pressure already thin supplies of medical equipment, tests and manpower, all of which are needed to fight Covid-19. It could also sow confusion, as patients with fevers and coughs from flu rush to hospital emergency rooms in fear of Covid-19.