It’s not too late to get a flu shot

In the United States, annual flu vaccination campaigns begin in early September, before temperatures begin to cool and the cycle of people contracting and spreading the virus begins. The Centers for Disease Control and Prevention recommend that most people will be vaccinated as soon as updated vaccinations are available for the season. And in an ideal world, everyone would be vaccinated by the end of October.

But what if you missed the pop-up vaccine clinic at work and are putting off going to a pharmacy or doctor’s office for your shots?

Experts, including those at the CDC, say it’s better to get the vaccine late than skip it altogether. Flu season runs from October to May, usually peaking in February. Getting vaccinated at any time during the season can help prevent you from getting sick missing work or school.

The effectiveness of vaccines can vary greatly depending on the season. But even if the vaccine fails to prevent infection, it can still reduce the rate of infection severity of symptoms and reduce your chances of hospitalization, said Dr. Sean Liu, assistant professor of infectious diseases at the Icahn School of Medicine at Mount Sinai in New York City. In vulnerable groups, such as pregnant women, older adults and very young children, the vaccine can also save lives, Dr. Liu said. For example, a 2022 study in children found that the flu vaccine reduced children’s risk of severe life-threatening flu by 75 percent.

As more people get vaccinated, the risk of exposure for everyone decreases. “By getting vaccinated against the flu, you are not only helping to protect yourself, but you are also indirectly helping to protect people in the community who are at greater risk of getting sick,” said Dr. Liu.

Scientific evidence from decades of monitoring flu vaccines in the United States shows that the vaccines have an excellent safety profile and minimal side effects. Most of these side effects, such as muscle aches, headaches, and a general feeling of malaise, are simply signs that your body is learning how to fight the flu based on bits of the virus in the vaccine.

For those who are afraid of needles or want to avoid pain at the injection site, there is an option to get FluMist, a vaccine that is injected into the nose and is suitable for children and adults from 2 to 49 years old. But the spray is available at fewer pharmacies than the shots.

It takes about two weeks after vaccination for your immune system to produce enough antibodies to protect against the flu. “It’s not like a light switch,” says Dr. William Schaffner, professor of preventive medicine at Vanderbilt University School of Medicine.

In addition, children aged 6 months to 8 years who are vaccinated for the first time need two doses, approximately one month apart, to get full antibody protection. Ideally, you should plan to get your vaccines in time before flu activity increases and prior to major travel plans or family gatherings, said Dr. Schaffner.

What if you have already had the flu?

Although you should probably wait a few weeks before getting vaccinated if you are actively sniffling and feverish, there are still benefits to getting vaccinated after you have recovered from the flu.

“It’s not unheard of to have the flu more than once per season,” said Dr. Schaffner. That’s because there are often different types of flu viruses circulating each season, and infection with one doesn’t necessarily protect you from the other.

However, flu vaccines are designed to protect against four different flu strains that scientists expect to be dominant each season. (You may see the word “quadrivalent” on immunization posters and in vaccine brand names.)

And unless you have a positive test confirming you’ve had the flu, it’s also possible to mistake it for symptoms of the common cold, RSV, Covid or several other respiratory viruses circulating around the same time, said Dr. Schaffner.

Where can I find the vaccine?

Most pharmacies, primary care physicians, urgent care centers and county health departments will have flu vaccines on hand well into the spring. You can use the CDCs vaccines.gov database to find a location near you.

Flu vaccines are usually fully covered by health insurance, including Medicare and Medicaid. If you don’t have insurance, you may be able to access free or low-cost flu shots through a local community clinic, the department of public health, or federal initiatives such as the Vaccines for children program.

And if you’re still wondering when it’s best to get vaccinated, Dr. Schaffner is simple: this afternoon.