What can we expect from this flu season?

Last fall and winter were dark in more ways than one. As the days grew colder and shorter, COVID cases and deaths surged. We cloistered ourselves at home, and on the rare occasions we did venture out, we masked up and stayed the hell away from each other. But there was at least one bright spot during that lonely time: The last flu season wasn’t really a thing, possibly because of all the precautions we took. During the 2020 to 2021 flu season, 2,038 flu cases were reported to the CDC — versus 38 million cases the season before.

Yet some experts worry that this extremely low-key flu season came at a cost. Now, the easing of COVID restrictions in many places has increased our risk of exposure to the flu virus, and worrisome still, we didn’t develop natural immunity to it last season, making us even more susceptible. That’s why the infectious disease physicians Mic interviewed predict that this flu season will be worse than the last — although whether that means it’ll be average or worse-than-average remains up for debate. What we can say is that getting vaxxed against both COVID and the flu, and continuing to practice masking and other tried-and-true public health measures will be crucial in the coming months.

“Even if you were on the fence about [the flu shot] in previous years, this year is probably the year that you want to take it,” says Nasia Safdar, medical director of infection control at UW Health.

Before we move on to experts’ flu season forecasts, though, let’s specify what they mean by “natural immunity”: “Natural immunity” refers to the immune defenses you build up when you’re exposed to a virus or other pathogen, versus “vaccine immunity,” which you gain in response to a vaccine. The problem is, natural immunity fades over time, and since we weren’t really exposed to the flu virus last year, we didn’t get the immune boost needed to protect ourselves from this year’s flu virus, as University of Pittsburgh researchers pointed out in a recent paper (although it has yet to undergo peer review).

None of that would matter if, say, 90% of people got their flu shot every year, says David Cennimo, an infectious disease specialist at Rutgers New Jersey Medical School. But according to the CDC, only around half of people in the U.S. do so. “A lot of what the pessimists like me are saying is, if people don’t’ get vaccinated, and we didn’t boost infection-derived immunity all across the population last year, we’d potentially have a larger pool of susceptible people which could all get sick at once,” Cennimo says.

Last year, we saw low levels of the flu not only in the U.S., but globally, he explains, “almost certainly” because of social distancing, masking, and other non-pharmaceutical measures. But our behaviors have changed since then. Even he’s traveled and gone to the theater (albeit with a mask). As a result, “we can expect that our flu risk will increase,” he tells Mic.

Australia, whose flu season is opposite of ours — April to October — is often a bellwether of our own. The country also saw historically low case and death counts last flu season. Now, “they still have pretty low influenza cases, although more than there were last year,” Cennimo says, which could be good news for us, except “we really don’t look like Australia” — its COVID restrictions are considerably stricter.

One thing he worries our flu season might have in common with Australia’s this time around: a dip in vaccination rates. He suspects that before the COVID jab was available, people probably reasoned they’d at least get vaccinated against the flu. Now that more of them are vaccinated against COVID, the “scarier” disease, they may no longer see a pressing need for the flu shot.

The U.S. is already seeing a rise in respiratory syncytial virus and other respiratory viral illnesses, according to Cennimo, another concerning sign of what’s to come. Put another way, whatever is enabling people to contract these illnesses now will also allow them to come down with influenza, also a respiratory viral illness, when it starts to climb.

The experts Mic spoke to agree that the upcoming flu season will be worse — but differ on what “worse” will look like. “It’s going to likely be either a typical [flu] season, which is just several thousand cases, or a bad season,” Safdar says. Cennimo, on the other hand, predicts that we’ll have a typical flu season, but it’ll feel worse than usual, since many of us have become complacent in the wake of the flu’s “disappearance” last season.

If you do experience respiratory symptoms (like a cough or stuffy nose) — which will, again, be more likely now that we’re out and about again — you’ll probably find yourself standing in line for a COVID test, which might also make this flu season feel worse, Cennimo says. Because COVID and the flu are “clinically indistinguishable,” he recommends getting tested for both.

Safdar agrees. She suggests first getting tested for whichever is more prevalent, and if you get a negative result, signing up for a test for the other. While Cennimo notes that some facilities test for these diseases one at a time, he points out that a lot of commercial platforms test for them simultaneously, using a single nasopharyngeal swab.

The upcoming flu season is so tricky to forecast partly because of the capricious nature of COVID. “I think we’ll certainly see flu,” Safdar tells Mic. “COVID is a little bit more unpredictable because it goes up and down, so the surges may not exactly coincide, but I think it’s safe to say there’ll be plenty of COVID circulating and plenty of flu.”

Although new COVID cases and hospitalizations have been on the decline since mid-September, according to the New York Times, Cennimo worries that if we backslide on these numbers, we could see hospitals becoming overwhelmed again, with doctors like himself wondering whether patients are on a ventilator for COVID or the flu. “Hopefully the COVID surge won’t be nearly as bad, but we don’t know,” he says. The situation will likely vary state to state, he adds, as has been the case throughout the pandemic.

He hopes that the rising COVID- vaccination rates will lower the chances of a “twindemic” overwhelming the healthcare system. But he’s especially concerned about those who have yet to be vaccinated against COVID or the flu. “I’ll be honest, I worry a little bit that those overlap,” he says. While some people are skeptical of the COVID vaccine in particular, he notes, it seems unlikely that those who have held out on getting it would be eager to get a flu shot.

To protect yourself and others, “you absolutely want to get the flu shot this year and, of course, the COVID-19 vaccination,” Safdar says. Since flu cases typically start to surface toward the end of October, and it takes at least two weeks post-vaccination for the body to start making protective antibodies, she explains, now is a good time to get the flu shot.

Both she and Cennimo stress that you do not have to “time” your flu and COVID shots. It’s totally fine to get them at the same time. At first, doctors couldn’t administer other vaccines two weeks before or after delivering the COVID vaccine because otherwise, they’d have a hard time teasing apart the source of any reactions that might occur, according to Cennimo — not because it would cause something awful to happen. In the same vein, getting two vaccines at once won’t “stress” your immune system, he adds, especially if you consider how many germs you encounter in a given day.

The absence of the flu last year is evidence that you no longer need to accept that you’ll get sick during flu season, Cennimo says, because behaviors like wearing a mask and washing your hands really do protect you. None of this is to say you should be a hermit, but you’ll want to do what you can to minimize your risk, he says. Eat at restaurants that require proof of vaccination, for example, and wear a mask while shopping. Keep an eye on COVID and flu case counts in your community, and respond accordingly. If you have respiratory symptoms, avoid public places so you don’t expose anyone, Safdar says. You’ll probably want to get tested for both COVID and the flu.

Basically, it’s still too early to let our guard down. As he we head into another pandemic winter, the best way to protect yourself is to get both the COVID and flu shots, and even then, as Cennimo puts it, you don’t want to test their limits.