There’s a saying among flu experts that goes, “If you’ve seen one flu season, you’ve seen one flu season,” says Pritish Tosh, MD, infectious disease specialist at the Mayo Clinic in Rochester, Minnesota. “I’ve been studying the flu for over a decade, looking at internal data, external data, public health trends, and every year I’m surprised at what influenza does,” he says.
Given all these curveballs, infectious disease specialists are wary about making predictions about future flu seasons. But Dr. Tosh and others note that, if recent history is any indication, the United States can expect an increase in flu activity after two years of fewer cases.
Read on to learn more about what might be coming in the months ahead and what you can do to fight the flu.
Why Does the Coming Flu Season Seem Different?
COVID-19 Precautions Stopped the Flu in Its Tracks
The pre-pandemic 2019–2020 flu season was considered moderate, with about 35 million people in the United States becoming infected with influenza. This led to 380,000 hospitalizations and 20,000 deaths, according to the Centers for Disease Control and Prevention (CDC).
But once COVID-19 began to hit the United States in spring 2020, the flu essentially disappeared. “That was the start of some of the preventative behavioral changes, such as people avoiding crowded places, people social distancing, and that sort of thing,” says Tosh. “Influenza cases plummeted — like, dropped off a cliff.”
For the 2020–2021 flu season, the CDC recorded only 2,038 reported flu cases, with an estimated 700 deaths due to flu complications.
The Easing of COVID-19 Restrictions Caused an Uptick in Flu Cases
The 2021–2022 flu season was another odd one, says Tosh. As COVID-19 restrictions continued to disappear and more people began taking off their masks, gathering indoors, and otherwise going back to “normal” life, the flu began circulating again.
The CDC estimates that between 8 and 13 million people got sick with the flu during the 2021–2022 flu season, with a surprising uptick in cases in March and April 2022 — the first time that the flu peaked that late in the season since 1982, said Lynnette Brammer, MPH, head of the CDC’s domestic influenza surveillance team, in an interview with NBC News. Typically, the flu season peaks between December and February, the CDC notes.
“Overall, the number of hospitalizations was less than we would see in normal previous years [pre-pandemic], but the duration certainly was not something we were used to,” says Tosh.
Evidence Suggests a Challenging Flu Season Ahead
With very few COVID-19 restrictions now in place, either in the United States or around the world, infectious disease experts are seeing evidence that suggests the flu will be making a comeback.
As a predictor for what’s going to happen in the United States and the rest of the Northern Hemisphere, scientists look to flu trends in the Southern Hemisphere, where flu season begins six months earlier. “It’s not always an accurate forecast for our season, but if the same flu strains are dominant, things tend to look about the same,” says Tosh.
This summer, the World Health Organization (WHO) reported increasing influenza activity in some Southern Hemisphere areas, particularly in temperate zones such as southern Africa, Australia, and New Zealand.
In July this year, during Australia’s winter, flu cases surpassed rates seen prior to the pandemic, with weekly case numbers higher than the country’s five-year average, according to the Australian Department of Health and Aged Care.
In addition to these high rates, the Australian metrics showed that flu season began in April, about two months earlier than usual, but it also ended a little earlier than what would normally be expected. Will the flu season also begin early in the United States? “It’s still difficult to predict,” Tosh says.
Our Natural Immunity to the Flu May Be Reduced
While no one wants to be sick with the flu, the lack of exposure to these viruses over the past two flu seasons might be problematic.
Pre-pandemic, about 10 percent of the U.S. population would get influenza in a typical flu season, says Tosh. “Those people will get a bounce in their immunity, and there will also be a subsequent bounce in population immunity,” he says — meaning the community as a whole would benefit from the extra immunity, including people who never got the flu.
Even people who are exposed to influenza but don’t get sick have an advantage going forward, because their immune systems make antibodies that “remember” the virus and how to attack it.
“Because the last few flu seasons have been so mild, there may be as a result a decrease in the population immunity to influenza and so that would favor a worse flu season, but how that will play out is tough to say,” says Tosh.
Tips to Prevent the Flu and Pneumonia
Some Shifts Brought on by the Pandemic May Help Keep the Flu in Check
The COVID-19 pandemic has had a lasting impact on some people’s behaviors and attitudes, and that might work to our collective favor in the fight against the flu. “For example, although many people have gone back to in-person work, there are going to be more people working from home than before the pandemic,” Tosh says.
Although 60 percent of U.S. workers have jobs that require them to leave their houses, those who have that option to work from home are often continuing to do so, at least part of the time, according to a February 2022 Pew Research poll. More new jobs are allowing employees the option to work from home, too.
“We are also seeing fewer people choosing to go into work when they are sick, which is a good thing,” says Tosh. Pre-pandemic, it was often viewed as a “badge of honor” to show up to work even when battling some sort of cold or other contagious illness, but now if you do that, you may find yourself shunned by your coworkers.
“I think you’re going to see fewer sick people show up to work because the social pressure is different, and that change is probably going to last for a long time,” Tosh says.
Another Good Sign: This Year’s Flu Vaccine May Be a Match for the Circulating Strains
A variety of data, including information about what flu viruses are circulating in different areas of the world at different times, are analyzed by the WHO and the CDC to decide what strains to include in the flu vaccine.
The scarcity of flu strains in the 2020–2021 season made that task especially difficult, and the flu vaccine was not a great match for the virus last year, says Tosh. CDC data indicates it only reduced a person’s chance of getting a mild case of the flu by about 16 percent. Usually, the flu shot provides between 40 and 60 percent protection against infection, per the CDC, but can still reduce the risk for severe illness and hospitalizations.
This year, the strains circulating in the Southern Hemisphere were well matched to the vaccine, says Tosh. “That doesn’t automatically predict a good match in the Northern Hemisphere, but it’s a good sign,” he adds.
Getting a Flu Shot Is the Best Way to Avoid the Flu and Its Complications
The best protection against influenza is to get a flu vaccine, says Tosh. “We sometimes forget that in a usual flu year, tens of thousands of Americans die from influenza, and a lot of that is due to severe complications, which is often preventable with the vaccine,” he says.
“One thing that I hope we’ve learned from COVID is that even if you get an infection despite being vaccinated, the severity of the illness decreases. Getting the influenza vaccine reduces the risk of hospitalization and death due to the flu, especially in high-risk people,” says Tosh. Older people, people with certain medical conditions, and young children are at higher risk for complications of the flu, according to the CDC.
In addition to getting the flu vaccine, there are other ways to protect yourself from influenza. The CDC recommends preventive actions to stop the spread of germs, which include the following measures:
- Avoid close contact with sick people.
- When you are sick, try to limit your contact with others.
- If you have a flu-like sickness, try to stay at home for at least 24 hours after your fever is gone.
- Cover your nose and mouth with a tissue when you cough or sneeze, then throw away the tissue and wash your hands.
- Wash your hands often and avoid touching your eyes, nose and mouth.
- Clean and disinfect surfaces and objects that may be contaminated with flu germs.