As the muggy summer months drag on in the northern hemisphere, public health officials are already gearing up for the cold fall and winter. Or as they call it, flu season.
The influenza virus circulates predictably around October, but this year there’s an added curveball: the ongoing Covid-19 pandemic, which will almost certainly continue through the winter months. Scientists aren’t sure exactly what to expect with two respiratory infections spreading simultaneously, but they do know they could be a deadly combination: “A potential co-circulation of Covid-19 and flu could place a tremendous burden on our nation’s healthcare system and result in many illnesses, hospitalizations, and deaths,” Jasmine Reed, a spokesperson for the US Centers for Disease Control and Prevention, said in an email.
Accordingly, public health professionals have one clear message to Americans: Get your flu vaccine, and get it early.
Does the flu vaccine protect you from Covid-19?
No—but it can still save your life.
The flu is caused by an influenza virus, while Covid-19 is caused by a coronavirus called SARS-CoV-2. The flu jab can only prepare your immune system for future encounters with influenza, not SARS-CoV-2.
But notably, the two viruses cause a lot of the same symptoms. Both attack airways and lungs, and cause fevers, sore throats, and even vomiting and diarrhea. (The only symptoms that don’t commonly overlap are the loss of smell and taste and toe lesions associated with Covid-19—but that doesn’t mean they can’t happen to individuals with the flu.)
There’s danger enough in either one of these infections alone; global estimates suggest that the flu kills 389,000 people annually, and Covid-19 has killed over 742,000 people at the time of writing. But the fear in the coming months is that a person could develop both of these infections either simultaneously, or one right after the other. Getting your flu vaccine as early as you can will lower the odds of that happening.
“My biggest concern is the damage to the respiratory tract,” says MeiLan Han, a pulmonologist at the University of Michigan. If either the flu or Covid-19 damage the lungs significantly during one infection, and the organs don’t have time to fully heal afterward, a secondary infection could be harder to fight off.
A person who contracts a relatively mild case of Covid-19 could then wind up in the hospital if they catch the flu shortly after, even if normally, they’d be able to fight off the flu at home.
That’s dangerous for individuals, and also for the hospitals that may have to deal with the burden of more patients. “When a hospital is surging with Covid-19, there’s very little bandwidth to do anything else,” says Han. It’s also expensive: The American Hospital Association estimates that Covid-19 costs the US hospital system some $50.7 billion per month, and some individuals who have been hospitalized have gotten bills in the hundreds of thousands of dollars.
People who are at high risk of developing severe flu cases overlap with those at high risk of Covid-19 complications, too. These people are older adults, people with pre-existing conditions or who are otherwise immunocompromised, and pregnant people. The only exception is children; the flu can be deadlier in pediatric patients, but Covid-19 is usually not. That said, children have died of Covid-19, and they can spread the virus to others.
The only way to prevent either of these infections is with a vaccine. Vaccines for Covid-19 are still in the works. Flu vaccines, however, are developed and distributed annually. Every year, the World Health Organization estimates which strains of the ever-mutating flu are most likely to be circulating, and tailors a vaccine to match (this year, it’s a combination of three different strains).
Flu vaccines aren’t always 100% effective, but even a shot with about 40% efficacy, like last year’s, can protect some people from getting sick, or help them fight infections a little more easily. And that’s especially important during the Covid-19 pandemic.
When and where can I get a flu vaccine?
The answer varies globally, but typically, governments purchase flu vaccines for people living in their countries. These vaccines can then be distributed through doctors’ offices, schools, and offices. Some of those venues may not be available this year because of the ongoing pandemic, so public health officials are gearing up to rely on other methods of distribution, like pharmacies, supermarkets, and even drive-by distribution points, even more than usual.
This year, the US CDC estimates that vaccine manufacturers will supply the country with 194 to198 million doses of the flu shot, compared to 175 million doses last year: They’re expecting an increased demand for flu vaccines because of the pandemic. The organization should have a tool to look up where you can get a flu vaccine ready by Sept. 1, according to NPR. Because flu shots are a form of preventative medicine, insurance companies and federal health insurance in the US should cover them free of charge.
The sooner you can get a flu shot, the less of a chance you’ll have of getting seriously ill during the fall and winter months. It’ll also streamline the process of getting a Covid-19 vaccine when they become available; at the earliest, that will realistically be some time next year. The more that vaccine administrators can avoid bottlenecks of high demand for the flu vaccine while they’re giving Covid-19 vaccines, the better.