Following the death of over 4 dozen people in South Korea after receiving their seasonal flu shots, more people are increasingly interested in flu shots side effects in the 2020/2021 season. This comes after 59 people died after receiving flu shots, and Singapore suspended two of the vaccines as a precaution. Researchers are currently scrambling to find if any link exists between the current COVID 19 pandemic and the exacerbation of the flu shot side effects.
How do flu vaccines work?
The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. Flu vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with the viruses that are used to make the vaccine. Most flu vaccines in the United States protect against four different flu viruses (“quadrivalent”); an influenza A (H1N1) virus, an influenza A (H3N2) virus, and two influenza B viruses. There are also some flu vaccines that protect against three different flu viruses (“trivalent”); an influenza A (H1N1) virus, an influenza A (H3N2) virus, and one influenza B virus. Two of the trivalent vaccines are designed specifically for people 65 and older to create a stronger immune response.
What kinds of flu vaccines are available?
CDC recommends the use of any licensed, age-appropriate influenza vaccine during the 2020-2021 influenza season, including inactivated influenza vaccine [IIV], recombinant influenza vaccine [RIV], or live attenuated influenza vaccine (LAIV). No preference is expressed for any influenza vaccine over another. Both trivalent (three-ingredient) and quadrivalent (four-ingredient) influenza vaccines will be available.
Trivalent flu vaccines include:
A trivalent flu shot made using an adjuvant (an ingredient that helps create a stronger immune response), approved for people 65 years of age and older.
Quadrivalent flu vaccines include:
Standard-dose quadrivalent influenza shots that are manufactured using viruses grown in eggs. These include Afluria Quadrivalent, Fluarix Quadrivalent, FluLaval Quadrivalent, and Fluzone Quadrivalent. Different influenza shots are licensed for different age groups. These four vaccines are approved for people 6 months of age and older. Most influenza shots are given in an arm muscle with a needle. One quadrivalent influenza shot (Afluria Quadrivalent) can be given either with a needle (for people aged 6 months and older) or with a jet injector (for people aged 18 through 64 years only).
A quadrivalent cell-based influenza shot (Flucelvax Quadrivalent) containing virus grown in cell culture, which is licensed for people 4 years and older. This vaccine is egg-free.
Recombinant quadrivalent influenza shot (Flublok Quadrivalent), an egg-free vaccine, approved for people 18 years and older.
A quadrivalent flu shot using an adjuvant (an ingredient that helps create a stronger immune response), approved for people 65 years of age and older.
A quadrivalent high-dose influenza vaccine (Fluzone High-Dose), licensed for people 65 years and older.
A live attenuated influenza vaccine (FluMist Quadrivalent), which is given intranasally. This vaccine is approved for people 2 through 49 years of age. Live attenuated influenza vaccine should not be given to people who are pregnant, immunocompromised persons, and some other groups.
There are many flu vaccine options to choose from, but the most important thing is for all people 6 months and older to get a flu vaccine every year. If you have questions about which vaccine is best for you, talk to your doctor or other health care professional. More information on approved flu vaccines for the 2020-2021 flu season, and age indications for each vaccine are available in CDC’s Table: U.S. Influenza Vaccine Products for the 2020-2021 Season.
Are any of the available flu vaccines recommended over others?
For the 2020-2021 flu season, the Advisory Committee on Immunization Practices (ACIP) recommends annual influenza (flu) vaccination for everyone 6 months and older with any licensed, influenza vaccine that is appropriate for the recipient’s age and health status, including inactivated influenza vaccine (IIV), recombinant influenza vaccine (RIV), or live attenuated nasal spray influenza vaccine (LAIV4) with no preference expressed for any one vaccine over another. There are many vaccine options to choose from, but the most important thing is for all people 6 months and older to get a flu vaccine every year. If you have questions about which vaccine is best for you, talk to your doctor or other health care professional.
What are the side effects of the flu vaccine?
Whether you get a flu shot or the spray-mist type, side effects are generally no big deal. You may experience the following:
Soreness or aching in your arm
Your arm might be sore or uncomfortable after getting the shot, but this is a good thing: It means your immune system is responding to the vaccine and creating antibodies, says Dr. Kemmerly. Plus, it’s usually “one day of discomfort,” Dr. Vicetti adds, “and not everybody gets that [side effect].”
Redness, pain, or swelling at the injection site
This is another good sign that your immune system is raring to go and responding to the vaccine properly, Dr. Kemmerly says. Plus, any time something breaks the skin barrier (like a needle), it may get red and swollen as your body reacts to it as a foreign object. This side effect is common and should only last a few days.
Low-grade fever
Experiencing a low-grade fever (below 101 degrees) after the flu shot is possible, but it’s not very common. If it’s any higher than that, you may already be sick with another virus that commonly circulates during flu season. A person might catch a cold, for example, or RSV (respiratory syncytial virus, a common childhood illness).
Oftentimes, people delay getting a flu shot until flu season is in full swing, Dr. Kemmerly points out. They were already “incubating” the flu virus and “then, lo and behold, they got the flu—but totally unrelated to the flu shot,” she says.
Headaches, nausea, or fatigue
These are all totally normal reactions as your body responds to the flu vaccine, the CDC says.
Fainting or Dizziness
Like any other vaccine, some people may experience dizziness or fainting after getting a flu shot, but this has much more to do with the process—getting a needle poked into your arm than the vaccine itself, the CDC says. The organization emphasizes that nearly all vaccines receive reports of people fainting afterward, so it’s not unique to the flu shot alone. ALSO READ: Flu Seasons Around the World
Sneezing or Coughing
The nasal flu vaccine, the type your child might get if he or she doesn’t have asthma or a recent history of wheezing, can cause some of the same side effects as the flu shot—minus the sore arm—plus some additional ones. “There can be some coughing and sneezing,” Dr. Kemmerly notes, “but for the most part people feel pretty good.”
Sore throat
While the flu shot is unlikely to give you a sore throat, the CDC says that you may experience this side effect with the nasal flu vaccine. If you happen to experience this side effect, it will usually happen soon after you get vaccinated and be mild and short-lived.
Guillan-Barré syndrome
There are people who do develop serious side effects after getting the flu vaccine, including Guillain-Barré syndrome (GBS), a neurologic condition that attacks your body’s nerve cells, in turn causing muscle weakness or paralysis in severe cases. (These people fall on the list of people who should not get a flu shot.) Before you freak out, know that this condition is extremely rare. In fact, for every 1 million flu shots given, only one or two of those people will develop GBS, the CDC states.
Flu shot side effects when pregnant
Maternal cold or flu with fever during pregnancy may be linked to birth defects. A study from the Centers for Disease Control and Prevention (CDC) found that women who had a cold or flu with fever just before or during early pregnancy may be more likely to have a baby born with a birth defect. For this reason, skipping your flu shot while pregnant is not recommended. Pregnant women have a weakened immune system, heart, and lungs and are more vulnerable to catching viruses like the flu. If you’re pregnant and get the flu, your symptoms may be more serious and could require a hospital visit. Some people might have a headache, muscle aches, fever, nausea or feel tired. If these symptoms occur, they usually begin soon after the vaccination and last 1-2 days. None of the common side effects endanger the baby.
Flu shot side effects for baby and toddlers
Babies younger than 6 months can’t receive the flu vaccine because their immune systems aren’t strong enough yet. Those older than 6 months should get the flu shot every season to prevent health complications and spread the illness to others.
So when is the best time to get it? Because flu season strengthens in the fall and winter and because it takes two to four weeks to build effectiveness, the CDC recommends getting the flu vaccine by the end of October. However, getting the vaccine later still protects against the illness. Side effects of the flu shot for infants include; soreness or redness in the area of the flu shot, swelling in the area of the shot, headaches, mild fever, and nausea.
