As the fall approaches, experts and doctors worry about the annual flu season.
While there's no way to determine how bad a flu season will be, many are concerned that the overlap between the flu season and the coronavirus pandemic could cause issues.
"The biggest concern is that we have seasonal increases in the flu from December or November through March, and at that time, many hospitals go into surge crisis (mode)," said Dr. Albert Ko, a professor of epidemiology and medicine at the Yale School of Public Health in New Haven, Connecticut. "Beds are filled, and so the big concern is that if our hospitals are already filled with flu, what happens if we have a parallel epidemic of Covid-19? How do we deal with that?"
While formal guidance on the 2020-2021 flu vaccine has not yet been issued, according to Dr. Tania Elliott, a clinical instructor of medicine and immunology at NYU Langone Health in New York, early fall is the best time to get the vaccine.
"September and October are generally the best months to get (the flu shot)," she said. "There is little value in getting the flu shot earlier than this, because the flu shot effectiveness will wane over time, meaning you won't be protected later in the season."
Justin Lessler, Ph.D., an associate professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health in Baltimore, advised getting the shot as soon as it's available in your area, with one exception: If you have an upcoming doctor's appointment, it's better to wait until then rather than go to a medical facility twice in a short period of time.
"I would suggest people get the shot as soon as they are available, because we don't know when the flu wave will be coming," Lessler said.
Most people should get the flu shot, unless their medical provider specifically advises against doing so. Since the vaccine is produced with a technology and method that uses eggs, check in with your doctor if you have an egg allergy.
Very young children who are under six months old and people with some medical conditions are advised against getting the vaccine, but Ko stressed that the vaccine is almost universally safe for the general population.
"There are not very many contraindications to taking the vaccine," Ko said. "These vaccines have been given for many decades, and they are almost universally safe except for those conditions."
Lessler said that, at best, the flu shot can help limit the amount of trips people have to make to health care facilities.
"If the flu is sending a lot of people to health care facilities, then that's increasing their risk of catching coronavirus," he said.
"Even though it's not nearly as deadly as Covid-19, the flu still can be quite dangerous, and we depend on the same resources to keep flu patients alive — like ventilators and oxygen — as we depend on to keep really sick Covid-19 patients alive," Lessler said. "If you have a really big flu wave you could potentially see an increase in deaths because people are competing for resources, if you let things get to that point."
Ko suggested that too many cases of the flu could also lead to another shortage of personal protective equipment (PPE), in addition to causing problems with testing. Lessler also said that someone who catches and survives one virus might be more susceptible to another.
"We know that if you have a big infection, it leaves you weaker, particularly among older people, who are at the most risk of dying from Covid-19," Lessler said. "We worry that someone recovering from one respiratory infection and getting a second, which might mean a more severe outcome."
While there's no way to know in advance how bad the coming flu season might be, doctors suggest that measures like mask-wearing and social distancing could help limit the spread of the flu, as well as Covid-19.
"These are different diseases, but transmit in a similar way," said Lessler, citing a recent study from Hong Kong that showed Covid-19 measures helped limit flu transmission. "Everything we do to impact Covid-19 transmission will help with the flu."
"Masks are going to be big in helping slow flu (transmission,)" Ko added.
Canada has reported "exceptionally low levels" of influenza in recent weeks, as have countries that report weekly flu surveillance statistics like the U.K. and Australia.
Covid-19 measures might change the way that the flu vaccine is distributed. Instead of busy pediatric offices or workplaces offering vaccinations, Elliott suggested that people may see more "drive-up vaccine clinics" or strictly scheduled appointments.
It's important to note that the flu shot can not give you the flu and it's as important as ever for people to get vaccinated this year.
"It will be very important to get the flu shot this year given that we are likely to see both the flu virus and Covid-19 circulating," she said.