Fall is coming. As the leaves change and temperature falls, healthcare providers across the country face a new and sobering challenge: navigating flu season during a global pandemic. 

The early symptoms of COVID-19 are, at this point, familiar. Infected patients experience fever, chills, cough, fatigue, headache, sore throat, congestion, and nausea. The problem is that many of these symptoms also overlap with flu effects. Given that both diseases are contagious respiratory illnesses, it may be difficult — even impossible — for doctors to distinguish COVID-19 cases from flu cases without testing. 

“When someone presents to a physician with fever, cough, malaise, unless it’s one of the few things peculiar to COVID-19, like a loss of smell, it’s hard to tell them apart when both are circulating in the community,” Benjamin D. Singer, an assistant professor of medicine at Northwestern University’s Feinberg School of Medicine, told reporters for the Washington Post

To make matters even more complicated, recent research indicates that a person can have the flu and COVID-19 at the same time. Because the two pathogens access our bodies via different cell receptors, SARS-CoV-2 and a flu virus could theoretically infect a patient simultaneously. One JAMA-published study of 1,200 patients in Northern California found that one in five studied COVID-19 cases were coinfected with another respiratory virus. 

Doctors are already stretched thin with finding, treating, and tracing COVID-19 cases; the prospect of doing so while simultaneously fielding the usual burden of flu cases poses a real and worrying challenge.

“This fall and winter could be one of the most complicated public health times we have, with the two [viruses] coming at the same time,” Robert Redfield, the director of the Centers for Disease Control and Prevention, shared in a recent interview

In the United States, flu season typically starts in the fall and peaks sometime between December and February — however, flu activity can last as late as May. While the health impact posed by the flu varies from year to year, the virus invariably adds a burden to the healthcare system. During the 2018-2019 influenza season alone, the CDC estimated that the flu was linked to over 35.5 million illnesses, more than 16.5 million medical visits, 490,600 hospitalizations, and 34,200 deaths. 

In the context of the current pandemic, this disease burden creates two apparent problems. First, it increases the already-significant strain on medical professionals and hospital resources. 

Only a few months ago, hospitals in COVID-19 hotspots had to build temporary overflow facilities that could support the sudden influx of patients. While COVID-19 numbers have (with a few exceptions) ebbed across the country, the potential for a similar surge during the colder months is significant. If a COVID-19 surge coincides with a spike of flu cases, the resulting patient burdens could strain our medical resources. 

As one writer for Scientific American recently pointed out, “During the 2017–2018 flu season, local news outlets reported that hospitals across the country flew in nurses from other states, erected tents in parking lots and sent incoming ambulances to other facilities because of the overload of patients.” Handling that kind of influx amid a pandemic could prove disastrous. 

The second issue at hand is a diagnostic one. How can providers safely distinguish patients who have COVID-19 from those who might only have the flu? Thankfully, some steps have already been taken to make diagnostic efforts easier. 

Several weeks ago, the FDA issued emergency authorization to the CDC for a combination influenza and COVID-19 test. It is the third test authorized for this purpose so far and is designed to identify novel coronavirus genetic material as well as influenza A and B viruses. Because the test only requires a single swab, it may help to limit the demand for testing supplies and minimize the risk of exposure for the health care workers who collect samples. 

There are also some signs that because both diseases are communicated via respiratory droplets, the behaviors taken to limit COVID — i.e., social distancing, masking, closures — will also slow flu spread. 

But above all else, health care authorities are pressing the importance of flu vaccination. 

“Look, we don’t have a vaccine for COVID-19. We do have a vaccine for flu. Get the vaccine,” North Carolina’s state health director Elizabeth Tilson recently stated for Scientific American. 

CDC data indicates that less than half of Americans get their seasonal flu shots. CDC director Robert Redfield hopes that by boosting adult vaccination rates up to 65 percent, providers can limit the risk of flu patients overwhelming already-strapped healthcare facilities. To that end, the CDC has purchased over 9 million doses for distribution — a cut above the 500,000 the department usually buys. As the Washington Post reports on the move, “Health officials want uninsured adults who lost their jobs during the pandemic to have increased access to flu shots.”

As exhausting as the pandemic has been, health care providers need to stay vigilant and act proactively this flu season. If we encourage flu vaccination and maintain social distancing measures, we may be able to make it through the flu season without overwhelming America’s healthcare systems.