As the flu season takes off, you may be worried about getting sick. The number of hospitalizations from the flu this season have surpassed whats been seen the past 10 years at this time, and experts have been warning of a tripledemic with the uptick in COVID, RSV, and flu cases.
Its kind of cause for alarm, Dr. Megan Berman, associate professor of internal medicine at the Sealy Institute for Vaccine Sciences at the University of Texas Medical Branch Health, tells Fortune.
Experts say a flu shot is your best defense against the virus, but some people are opting to skip the vaccine, lamenting that they will get the infection anyway.
So can you get the flu after receiving the shot?
You can still get the flu but it may not be as severe
The flu vaccine usually reduces the risk of getting sick with the flu each year by between 40% and 60%, depending on the strain that circulates and how well the vaccine matches that strain.
While the vaccine cannot guarantee you wont get sick, it helps protect against severe illness that can lead to hospitalization and death, similar to the COVID shot. Data found this years flu shot reduces hospitalization risk by nearly 50%, per the U.S. Centers for Disease Control and Prevention (CDC). People with chronic conditions, like lung or heart disease, are at a higher risk of getting severely sick from the flu, so the vaccine is crucial in preventing hospitalization in this group.
When we talk about severe disease, were talking about people getting in the hospital, exacerbating underlying chronic illness, or dying from infection, Berman says.
In the 2019-2020 flu season, the CDC estimates that the vaccine prevented 7.5 million flu cases, over 100,000 hospitalizations and over 6,000 deaths.
You can get the flu before antibodies kick in
It takes two weeks for the body to generate an immune response after the jab. If you get the flu within that two-week window post vaccine, its likely because your body hasnt guarded itself against the virus yet. Also, you may have already had the flu when you received the vaccine.
You may have another virus with similar symptoms
Flu and COVID share a host of symptoms, including cough, sore throat, fever, chills and more. If you have flu-like symptoms and youve been vaccinated, it may be a different virus. Testing will give a clear answer, Berman says. She commonly sees patients who assume they had either COVID or the flu based on their symptoms but seldom have proof. She always tells them that its better to get tested instead of assuming a particular virus caused the symptomsit can lead many to think they are immune from an infection they never had, she says.
We have the capability to test, and a lot of people were just assuming they have something without actually knowing, she says. There are a lot of these viruses. They mimic one another.
There are also different treatments for COVID versus the flu (Paxlovid and Tamiflu respectively).
You might not have as strong of an immune response
Those 65 and older, who make up the bulk of hospitalizations from the flu every year, dont have as strong an immune response to the flu vaccine as those younger. The CDC recommends other vaccines for this population, some being higher dose, according to the CDC: Fluzone High-DoseQuadrivalent vaccine, Flublok Quadrivalent recombinantflu vaccine and Fluad Quadrivalent adjuvanted flu vaccine.
For people receiving immunosuppressive therapy, like for cancer treatment, or for those who have an autoimmune disorder, the immune response to the vaccine may also be less effective. If youre over 18, you can get the Flublok vaccine which can work better for this group.
If the pharmacy doesnt have the particular flu vaccine youre looking for, get the general vaccine thats available.
Any vaccine is better than no vaccine, Berman says.
The flu shot cannot give you the flu
Some worry whether the flu vaccine can actually give you the flu itself. However, the vaccine is made from an inactivated or killed part of the virus, so its not possible for the virus to replicate and cause illness.
Your body may have side effects right after the shot like a fever, soreness, headache, nausea or muscle aches, but its a sign of the body creating an immune response. The side effects subside within a few days.
As people travel for the holiday season and gather indoors when its cold, its recommended to do your part and stay protected even if youre not high risk, Berman says. Some people may think they dont need the flu shot, especially because its an annual vaccine. But similarly to wearing a seatbelt, getting the vaccine helps protect not just yourself but those around you from severe outcomes, she says.
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