The runny nose-and-fever illness known as flu (short for influenza) was less common than usual last year for Covid-related reasons. We all spent more time isolated at home, wore masks and washed or sanitized our hands regularly. As a result, hospital stays for flu dropped sharply and flu-caused deaths dropped by 95%, researchers say. (Only one U.S. child died.) But now a comeback is possible as Covid safeguards ease or end. "We've been concerned about vaccine fatigue and that people will be confused about whether or when they need the flu shot, and not very eager to once again roll up their sleeve," says Dr. William Schaffner, medical director of the National Foundation of Infectious Diseases. "Flu is a nasty virus and worth protecting against."

So it's especially important for students and adults to get flu shots this month or next. An updated version of the vaccine protects against four strains of the respiratory virus. "We really have to do everything we can to protect ourselves," says Dr. Lauren Block, a primary care physician on Long Island, N.Y. "That includes getting Covid vaccines, but also, don't forget about your annual flu vaccine." No vaccine is 100% effective, but a flu shot reduces your chance of getting very sick, being hospitalized or possibly even dying. In an average season, the U.S. has more than 9 million flu cases. Before 2020, tens of thousands of Americans were hospitalized or died from flu each year -- usually people who weren't vaccinated.

Here’s a medical reality that may seem ironic: Lack of exposure to the flu in 2020 could make Americans at greater risk this fall and winter. "Even in years when you don’t catch the flu, you are still often exposed to it," says Eili Klein, an associate professor of medicine at Johns Hopkins Medicine in Baltimore. "That exposure helps your immune system make antibodies that 'remember' the virus and how to attack it."

Researcher says: "Vaccinating as many people against flu as possible will be key to avoiding this [bigger impact] scenario." -- Dr. Mark Roberts, University of Pittsburgh Graduate School of Public Health

Medical professor says: "The flu may peak earlier this year. I wouldn’t recommend waiting until late November to get the flu shot." – Eili Klein of Johns Hopkins Medicine in Baltimore

Health journalist posts: "Getting vaccinated against the flu remains one of the simplest and best things you can do for your health, especially in a world where Covid-19 is unfortunately still around." – Ed Cara, gizmodo.com