As the coronavirus marches on with no end in sight and summer turns to fall, health officials across the country are increasingly concerned by a possible catastrophe: a “twindemic,” or surge in COVID-19 cases coupled with a severe, or even average, flu season.
Such a scenario “could be devastating to the health care system” that’s already stressed, said Fred Campbell, MD, an internal medicine physician and associate professor of medicine at UT Health San Antonio.
While doctors aren’t sure of exactly how the flu and COVID-19 might interact, one thing is clear. “Getting them simultaneously, which is possible, would be very problematic for an individual. That would amplify the effects,” said Robert Leverence, MD, chief medical officer of UT Health Physicians practice.
Both Drs. Campbell and Leverence emphasized the serious nature of the annual influenza outbreak. The Centers for Disease Control and Prevention estimates that last year cases ranged from 39 million to 56 million, resulting in up to 740,000 hospitalizations and from 24,000 to 62,000 flu-related deaths.
The good news is that there are vaccines for influenza, and getting the vaccine is more important now than ever.
“Only about half the population actually get the flu shot each year,” said Dr. Leverence. “So there’s a lot of opportunity here to do better, and this would be the right year to do better.”
Influenza is a seasonal virus and has several strains. “We know that we’re going to get influenza every fall and it will be a different mutation,” said Dr. Campbell. “It will change and mutate so that one vaccine is not going to work typically within year to year.”
Still, the vaccine can prevent or lessen the severity of the flu.
Aside from both being contagious respiratory diseases, COVID-19 and influenza share other characteristics.
“Unfortunately, many of the symptoms overlap,” said Dr. Campbell. “The ones most likely to be found in both these conditions are fever, cough and muscle aches. Shortness of breath is a sign of more serious illness in both influenza and COVID-19.
“No one at this point in time who’s worth his or her salt in the medical field is going to say they can distinguish the two in terms of symptoms,” he added. Only a test can do that.
The flu is highly infectious and highly virulent, “probably not quite as infectious as COVID-19, but very infectious and kills tens of thousands of people each year,” Dr. Campbell said. “In terms of its deadliness, it’s comparable.”
The two diseases are spread in almost exactly the same way, Dr. Leverence said, mainly by droplets made when people with the illness cough, sneeze or talk. “We’re hoping the same measures that reduce COVID transmission, such as distancing, wearing a mask, avoiding crowds, washing hands, those will also reduce flu transmission. Optimistically, we’re hoping it might be a light year for flu, but we can’t count on that.”
Dr. Campbell said the same populations are vulnerable to both the flu and the coronavirus.
“People over 60, people with chronic medical conditions — heart, lung, kidney, cancer conditions, the immunocompromised. And obesity is a risk factor,” he said. “The idea of protecting vulnerable populations is very similar to COVID-19 — the elderly and chronically ill. You can make the same argument for influenza, and it’s been made for decades. Everyone should get vaccinated, including young people, to protect them from spreading influenza to sick and elderly folks.”
Most medical experts agree that to be most effective, vaccines should be given at least by the end of October.
Dr. Campbell lamented the fact that so many Americans either dismiss flu shots or don’t take the time to get the vaccine. Similarly, recent statistics showed “up to 40% of people are hesitant to get a COVID vaccine once it’s available.”
Just as with the flu, he said, “if people don’t respond to the COVID vaccine, we’re going to be losing tens of thousands each year.”