As what seems like a never-ending fight against COVID-19 continues, a more familiar viral opponent is also preparing to attack: seasonal influenza.
Although there’s no surefire way to predict how severe this year’s flu season might be, health experts both nationally and locally are emphasizing the need to be ready. They say it’s more critical than ever to prevent as many flu cases as possible, so that the flu and COVID-19 don’t become a “twindemic” – a one-two punch that knocks us out.
The best way to prepare is for everyone over 6 months of age, with a few rare exceptions, to get a flu shot … and the sooner the better, according to Dr. Steven Lawrence, a Washington University infectious disease specialist at Barnes-Jewish Hospital.
“We need to do everything we can to prevent these two viral illnesses from peaking at the same time. We want to both decrease the number of flu cases and delay the onset of flu season,” Lawrence said. “Everybody should try to get their vaccine by mid-October or so, to help prevent the flu season from really taking off.”
While CDC statistics show that about half of Americans receive flu shots annually, “this year we certainly would like to see that percentage go higher,” he said, noting that flu vaccines prevent between 1 and 7 million flu cases – and between 3,000 and 10,000 deaths – in a normal year.
But 2020 is anything but normal, and it’s not hard to envision a scenario in which many people urgently need treatment for the flu and COVID-19 at the same time.
“During a typical flu season, hospitals can be stretched to the limits with patients extremely ill from the flu,” Lawrence said. If continuing or spiking COVID-19 cases also result in more hospitalizations, “the healthcare system could easily become overwhelmed. People would also have a very difficult time getting treatment for other serious conditions like heart attacks and strokes.”
The seasonal flu and COVID-19 are both respiratory viruses which also share many symptoms in common. They include a sudden onset of fever, chills, cough, sore throat, muscle or body aches, headaches, fatigue, and sometimes vomiting and/or diarrhea. Unlike the flu, COVID-19 can cause a loss of smell or taste, but only in some cases. These overlapping symptoms will make diagnosing one or the other illness more difficult.
“There’s certainly going to be a switch in strategy. We have been doing just COVID testing on people who have respiratory symptoms, and they will now have to be tested for both COVID and seasonal flu,” Lawrence said.
Public health experts have also expressed worry about people potentially getting the flu and COVID-19 simultaneously. That’s definitely a possibility, Lawrence agreed, and yet another unknown for doctors. “Because the virus that causes COVID-19 is new, there’s really no way to predict what impact that would have, both in terms of frequency or severity of illness,” he said, adding that “on an individual level, getting the flu vaccine will help prevent that ‘double whammy.’”
Asked whether those who have had already had COVID-19 and recovered also need a flu shot, Lawrence said, “The answer is yes … unless they’re still really ill from the virus.” Although flu shots do not provide protection against COVID-19, they will still benefit people whose bodies have already done battle with it.
As for those who may be thinking about skipping a flu shot and holding off until a vaccine is available for COVID-19 instead, the likelihood of that happening in 2020 is low, Lawrence predicted.
“The vaccine process takes time to do it right … and the Phase III trials for two of these products have just started,” he explained. “Clinical trials also have to include an observation period; some people get the vaccine, some get a placebo, and you have to watch them over a period of time that can’t be rushed no matter how many resources you throw at it.
“We have scientists and investigators around the country who are doing something that’s never been done before. If it happens it’s great, but it’s still going to take some time for the observation period to be completed so we can answer two basic questions: is it safe, and is it going to work?”
In the meantime, flu vaccines have already been widely distributed and in many cases are available at no charge. Vaccine manufacturers are projected to supply a record 198 million doses nationwide this year. Both trivalent (three-strain) and quadrivalent (four-strain) immunizations are available, along with a high-dose vaccine recommended for people age 65 and older and a quadrivalent FluMist nasal spray, which is used mainly in children over age 2.