The US may be in for a brutal flu season

Flu season is making a comeback. In the past two years, influenza and other respiratory viruses took a backseat to the more contagious COVID-19 variants. Pandemic precautions caused flu cases to drop to so low that at least one strain of the pathogen may have gone extinct. However, as restrictions loosen and kids return to school in-person, infectious disease experts are predicting high infection rates this year. Currently, there have been two confirmed reports of influenza in Delaware.

There are a few clear-cut indicators that this season will spell trouble for the US, infectious disease scientists say. In most years, flu seasons are a guessing game for those experts. Because the virus is constantly mutating, it’s hard to say for certain whether or not it’ll be a severe one. “We’ve been saying for the last few years to expect bad flu seasons, and that didn’t pan out,” explains Andrew Handel, a pediatric infectious disease specialist at Stony Brook University. “I think the public gets very frustrated with our predictions about flu seasons, but it’s all a prediction based on the best information we have available.” 

This time, however, a bad flu season abroad and low US vaccination rates for the flu are ominous forecasts for a rough winter ahead.  

Australia’s tough flu season

Jennifer Lighter, a pediatric infectious disease doctor at NYU Langone Health explains that flu seasons typically start in the southern hemisphere and move north. For this reason, the US turns to places like Australia to glimpse what we should expect to see in the fall and winter. Australia’s 2022 flu season was one of the worst in five years, according to a report from Australia’s Department of Health and Aged Care. Children between 5 to 9 had the highest flu case rates followed by children younger than 5 and people between 10 to 19 years old.

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Fortunately, there’s some good news. Another reason virologists closely follow Australia’s flu season is to identify which strains are circulating in the region. These strains are then considered in the final design of the annual flu vaccine, increasing the chances it will be highly effective. Lighter says that scientists don’t really have the estimates of how effective this year’s vaccine is until after cases emerge, but “we know that the current vaccine is matching well with what’s circulating in communities in the southern hemisphere.”

Low vaccination rates

Few people get their flu vaccines, and the COVID-19 pandemic made a flu shot less of a priority. The Centers for Disease Control and Prevention reports only 57 percent of children were immunized against influenza during the 2021-2022 season—a 5.6 percent drop from the pre-pandemic 2019-2020 season. The vaccine rates for adults were even lower; coverage for 2021-2022 ranged from 35.9 percent to 60 percent. 

“It’s always been a struggle to get a large portion of the population vaccinated against the flu,” explains Handel. “And over the last couple of years, fewer and fewer people have gotten flu vaccines, and that’s one more hole in the layer of protection against infections.”

There are many factors that go into a person’s decision not to get a vaccine. More recently, Handel says the discussions over COVID vaccine safety may have made Americans more hesitant about getting another shot in their arm. What’s more, people are experiencing vaccine fatigue—feeling burned out after constant immunizations and vaccine news.“People don’t want to spend time getting all of these vaccines, when they feel it’s not really all that beneficial or necessary,” Handel adds, even when the best evidence shows a flu shot helps.

Waning immunity

At the start of the pandemic, the flu and other respiratory viruses hit an all-time low. Public health practices including masking in public, online school, and social distancing prevented the influenza virus from spreading from person to person. 

While experts incorrectly predicted an enormous surge for 2021-2022 flu season as places opened back up, there is cause for concern for this upcoming season. To start, this will mark the third year in which most of the population’s immune systems have not been exposed to the flu virus. Both experts say it’s likely everyone’s immunity against influenza has waned. Waning immunity could lead to a greater chance of getting infected and having more severe illness.

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Winter respiratory viruses that normally circulate in the cold season, such as RSV, have also been running rampant in the last few months and overwhelming children’s hospitals. Young children are at especially high risk for severe flu because of their developing immune systems. “It might be their first time getting infected or because they’re getting exposed to multiple respiratory viruses all at once,” Handel explains. Even if your child has had a past flu case, he says it’s been a long time so there’s a chance their immunities are not as strong as it once was.” 

Other people at high risk for severe flu are people with asthma, COPD, older adults, and immunocompromised individuals. “The problem with kids not having a lot of immunity, and we’ve seen this with a lot of infections, is that these viruses are the ones that tend to pass on to grandparents and other adults who then spread it within the community,” says Handel.

How to protect yourself

Both experts agree the best way to stay protected this season is to get vaccinated. They recommend getting the flu vaccine now and scheduling it at the same time as your COVID boosters, which are already available in pharmacies. Besides achiness and fatigue, Lighter says you should not feel concerned about getting a shot in each arm on the same day. The flu shot will protect you as well as your family and community from the worst cases, she emphasizes. 

“The flu shot is analogous to the COVID shot. There may be breakthroughs but they’re both preventing severe disease and keeping you out of the hospital,” Lighter says. “And that’s really the main purpose of a vaccine—to keep you from getting significantly sick.”