The Flu Shot: What You Need to Know
Now, more than ever, you need a flu shot to avoid getting sick or developing complications if you do become infected. Read on for essential info about the coming season.
What’s the outlook for the 2023–2024 flu season? No one knows for sure, but public health experts in the United States are urging Americans to get their flu vaccines no matter what lies ahead.
Earlier in the pandemic, COVID-19 safety measures like mask mandates and stay-at-home orders worked to reduce influenza rates to historical lows. But now that these restrictions have largely been lifted, the flu is back.
In the United States, the Centers for Disease Control and Prevention (CDC) estimates that the 2022–2023 influenza season resulted in 26 to 54 million flu illnesses; 290,000 to 640,000 flu hospitalizations; and 19,000 to 57,000 flu deaths.
Getting a flu vaccine can reduce the risk you and those around you face. Here’s everything you need to know about how well immunization works, who should (and should not) get the shot, and whether it’s okay to get a flu shot and a COVID-19 vaccine or booster at the same time.
Will the Flu Shot Make You Sick?
How Effective Is the Flu Shot?
According to the CDC, vaccination reduces the risk of flu illness by between 40 percent and 60 percent during seasons when the vaccines are well matched to the viruses going around.
Getting the flu shot does not guarantee that you won’t come down with the flu for a number of reasons. Flu viruses are constantly changing (mutating), making it possible for them to evade the protections people have built up through flu vaccines.
Another factor affecting flu shot effectiveness is that sometimes the strains selected for the seasonal flu vaccine are a poor match to the circulating strains, according to the National Institute of Allergy and Infectious Diseases.
In addition, some older people and those with chronic health conditions may develop less immunity after vaccination, says the CDC.
But while flu vaccines are not 100 percent effective, people who are immunized are less likely to develop flu complications than people who aren’t.
It’s estimated that from 2010 to 2020, the yearly jab has prevented 719,000 hospitalizations and 60,000 deaths in the United States, according to the CDC.
“Even in years when the flu vaccine is a bad match, there is partial protection because one’s immune system can make antibodies that still recognize and bind to the influenza virus when new strains emerge unexpectedly,” says Kevin Harrod, PhD, a professor and infectious disease researcher at the University of Alabama’s Heersink School of Medicine in Birmingham.
What Types of Flu Vaccine Are There?
For the 2022–2023 flu season, all flu vaccines were quadrivalent, says the CDC, offering protection against four different flu viruses: an influenza A(H1N1) virus, an influenza A(H3N2) virus, and two influenza B viruses.
The vaccines included the following varieties:
- Standard-Dose Shot Made with virus grown in chicken eggs, these shots are approved for those who are 6 months or older.
- Cell-Based Shot These contain viruses grown in a culture made from mammal cells; they are approved for anyone who is 6 months or older. This vaccine is egg-free.
- Recombinant Shot These are synthetically created, egg-free vaccines approved for people age 18 and older.
- High-Dose Shot These shots contain a higher dose of antigen to help create a stronger immune response; they are approved for people age 65 and older.
- Shot Made With an Adjuvant Approved for people age 65 and older, these shots contain an ingredient called an adjuvant that helps create a stronger immune response.
- Nasal Flu Vaccine Also known as the “flu mist,” the nasal flu vaccine contains live virus and is given via the nose, notes the CDC. It is approved for people ages 2 through 49. Live flu vaccines should not be given to people who are pregnant or immunocompromised.
For people under age 65, the CDC recommended the use of any licensed, age-appropriate flu vaccine during the 2022–2023 flu season, with no preference for one over any other.
According to new guidelines instituted in spring 2022, the CDC advises people 65 and up to get a high-dose or adjuvanted flu vaccine. If none of these are available, the CDC says that people should get an age-appropriate standard-dose vaccine instead.
Should I Get a Flu Shot?
The CDC recommends that everyone 6 months and older get vaccinated every season, with a few rare exceptions. Children between 6 months and 8 years may need two doses during their first season of vaccination. The CDC advises people to get vaccinated by the end of October, though getting a flu vaccine anytime during the flu season can be beneficial.
Once you’re vaccinated, it takes a couple of weeks for your immune system to produce antibodies (proteins in the blood that fight infection).
The CDC says that an annual flu vaccine is especially important for people who face a higher risk of serious flu-related complications, including individuals in certain age groups — adults 65 and older and children under 5, especially those under age 2.
People with certain health conditions also fall into the high-risk category. These include:
- Neurological and neurodevelopmental conditions
- Blood disorders (such as sickle cell disease)
- Chronic lung disease (such as COPD and cystic fibrosis)
- Endocrine disorders (such as diabetes)
- Heart disease
- Kidney diseases
- Liver disorders
- Metabolic disorders
- People who are obese with a body mass index of 40 or higher
- People younger than 19 on long-term aspirin- or salicylate-containing medicines
- People with weakened immune systems due to disease (such as HIV or AIDS, or some cancers like leukemia) or medications (such as chemotherapy or radiation for cancer or corticosteroids or other immunosuppressants for chronic autoimmune conditions)
- People who’ve had a stroke
Other high-risk individuals include those who are pregnant or two weeks or less postpartum; those living in nursing homes or other long-term care facilities; and those from certain racial and ethnic minority groups, including non-Hispanic Black, Latino, and Alaskan Native and Native American.
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Are There Flu Shot Side Effects?
The most common side effect of a flu shot is soreness, redness, or swelling at the injection site. Some people also develop other minor problems such as a low-grade fever or headache, achiness, fatigue, or nausea, but these are usually mild and short-lived.
As with any medicine, a flu vaccine can cause a serious allergic reaction (anaphylaxis), but a study published in The Journal of Allergy and Clinical Immunology found the risk to be rare in all age groups, with 1.31 cases per million vaccine doses.
Some studies have found a possible small link between the flu shot and Guillain-Barré syndrome (GBS), a progressive nerve disorder that can cause profound weakness that lasts for weeks or longer. Overall, these studies estimated the risk for GBS after vaccination as fewer than 1 or 2 cases per one million people vaccinated. Other studies have not found any association, notes the CDC.
Who Should Not Get a Flu Shot?
The CDC advises people in the following groups not to get a flu vaccine:
- Children younger than 6 months
- People with severe allergies to any ingredient in the flu vaccine (other than egg proteins)
- People who have had a severe allergic reaction to the flu vaccine in the past
People who have an allergy to eggs, who have had Guillain-Barré syndrome, or who have had a severe allergic reaction to a previous dose of any flu vaccine should talk to their healthcare provider before getting immunized. In addition, If you’re not feeling well, you should check with your doctor before getting vaccinated.
Can I Get My COVID-19 Shot or Booster With My Flu Shot?
Yes, the COVID-19 vaccine or booster may be administered at the same time as the flu shot, says the CDC.
Previously, the agency had recommended that people get their COVID-19 shot at least two weeks before or after any other vaccinations. However, this was out of an abundance of caution during a period when these vaccines were brand new, the CDC states. They no longer have any concerns about getting a COVID-19 shot at the same time as any other vaccine, including the flu shot.
The same goes for children. If your child is eligible to get a COVID-19 vaccine or booster, it’s safe for them to get the flu shot at the same time.
Where Can I Get a Flu Shot Near Me?
The flu vaccine is available at pharmacies (including those inside CVS, Walgreens, Publix, Target, and other retailers), doctor offices, urgent care centers, workplace clinics, health clinics, and health departments.
If you’re having trouble pinpointing where to go in your area, you can use Vaccines.gov, which identifies sites that give flu shots by your ZIP code.
Flu shots are covered by most insurance plans. If you don’t have insurance, you may be able to get a free flu vaccine through your local health department; call to make sure. The website for the nonprofit organization Vaccinate Your Family is a useful resource for information on how to pay for flu vaccines for yourself and your family.