With flu season upon us during the COVID-19 pandemic, it’s doubly important to lessen the risk for getting the flu.

In a typical year, flu season occurs from fall to early spring. The length and severity of an epidemic may vary. Some lucky individuals can get through the season flu-free.

But be prepared to be surrounded by sneezing and coughing for a few months out of every year and to self-isolate and seek testing as soon as any symptoms appear.

According to the Centers for Disease Control and Prevention (CDC), the flu affects between 3 and 11 percentTrusted Source of the U.S. population each year.

Flu symptoms often include:

coughing
fever (not everyone with flu will have a fever)
headache
muscle or body aches
sore throat
runny or stuffed-up nose
fatigue
vomiting and diarrhea (more common in children than adults)

The symptoms that come with the flu can keep you bedridden for a week or more. An annual flu vaccine is the best way to help protect you against flu.

The CDC believes that flu viruses and the virus that causes COVID-19 will both be spreading during fall and winter. The symptoms of flu have major overlap with symptoms of COVID-19, so the flu vaccine will be more important than ever.

How does the flu shot work?

The flu virus changes and adapts every year, which is why it’s so widespread and difficult to avoid. New vaccines are created and released every year to keep up with these rapid changes.

Before each new flu season, federal health experts predict which strains of the flu are most likely to thrive. Influenza A and B viruses are the ones that cause seasonal epidemics. They use these predictions to inform manufactures to produce the appropriate vaccines.

The flu shot works by prompting your immune system to produce antibodies. In turn, these antibodies help the body fight off the strains of flu virus present in the vaccine.

After receiving the flu shot, it takes about 2 weeks for these antibodies to fully develop.

There are two variations of the flu shot that protect against different strains: trivalent and quadrivalent.

Trivalent protects against two common A strains and one B strain. The high-dose vaccine is a trivalent vaccine.

The quadrivalent vaccine is designed to protect against four commonly circulating viruses, two influenza A viruses, and two influenza B viruses.

The CDC doesn’t currently recommend one over the other. Check with your insurance provider and your doctor to get a recommendation.

Who needs a flu shot?

Some people may be more prone to getting the flu than others. That’s why CDC recommends that everyone 6 months of age or older be vaccinated against the flu.

The shots are not 100 percent effective in preventing the flu. But they’re the most effective method to protect against this virus and its related complications.

High-risk individuals

Certain groups are at an increased risk for getting the flu and developing potentially dangerous flu-related complications. It’s important that people in these high-risk groups be vaccinated.

According to the CDC, these individuals include:

pregnant women and women up to 2 weeks after pregnancy
children between 6 months and 5 years of age
people 18 and under who receive aspirin therapy
people over 65
anyone with chronic medical conditions
people whose body mass index (BMI) is 40 or higher
American Indians or Alaska Natives
anyone living or working in a nursing home or chronic care facility
caregivers of any of the above individuals

Chronic medical conditions that could increase your risk for complications include:

asthma
neurologic conditions
blood disorders
chronic lung disease
endocrine disorders
heart disease
kidney diseases
liver disorders
metabolic disorders
people with obesity
people who’ve had a stroke
people with a weakened immune system due to disease or medications

According to the CDC, people under the age of 19 who are on aspirin therapy as well as people taking steroid medications on a regular basis should also be vaccinated.

Workers in public settings have more risk for exposure to the disease, so it’s very important that they receive a vaccination. People who are in regular contact with at-risk individuals like the elderly and children should also be vaccinated.

Those people include:

teachers
daycare employees
hospital workers
public workers
healthcare providers
employees of nursing homes and chronic care facilities
home care providers
emergency response personnel
household members of people in those professions

People who live in close quarters with others, such as college students and members of the military, are also at a greater risk for exposure.

Who shouldn’t get a flu shot?

Some people shouldn’t get a flu shot for medical reasons. This is why it’s important for the rest of us to get it for herd immunity to protect them. Don’t get a flu shot if you have the following conditions.

Previous bad reaction

People who’ve had a bad reaction to the flu vaccine in the past shouldn’t get a flu shot.

Egg allergy

People who are severely allergic to eggs should avoid flu vaccination. If you’re mildly allergic, talk to your doctor. You may still qualify for the vaccine.

Mercury allergy

People who are allergic to mercury shouldn’t get the shot. Some flu vaccines contain trace amounts of mercury to prevent vaccine contamination.

Guillain-Barré syndrome (GBS)

Guillain-Barré syndrome (GBS) is a rare side effect that can occur after receiving the flu vaccine. It includes temporary paralysis.

If you’re at high risk for complications and have had GBS, you may still be eligible for the vaccine. Talk with your doctor to determine if you can receive it.

Fever

If you have a fever the day of the vaccination, you should wait until it’s gone before receiving the shot.

Are there any side effects to the flu vaccine?

Flu shots are safe for most people. Many people incorrectly assume that the flu vaccine can give them the flu. You can’t get the flu from the flu shot.

But some people may experience flu-like symptoms within 24 hours of receiving the vaccine.

Possible side effects of the flu shot include:

low-grade fever
swollen, red, tender area around the injection site
chills or headache

These symptoms may occur as your body responds to the vaccine and builds antibodies that latter will help prevent illness. Symptoms are typically mild and go away within a day or two.

What vaccines are available?

The flu shot is available in other forms, including high-dose, intradermal, and nasal spray.

High-dose flu shot

The Food and Drug Administration (FDA) has approved a high-dose flu vaccine (Fluzone High-Dose) for people 65 and over.

Since the immune system response weakens with age, the regular flu vaccine is often not as effective in these individuals. They’re at the highest risk for flu-related complications and death.

This vaccine contains four times the amount of antigens compared to a normal dose. Antigens are the components of the flu vaccine that stimulate the immune system’s production of antibodies, which combat the flu virus.

A 2020 studyTrusted Source confirmed some previous conclusionsTrusted Source that the high-dose vaccine has a higher relative vaccine effectiveness (RVE) in adults 65 and older than the standard-dose vaccine.

Intradermal flu shot

The FDA approved another type of vaccine, Fluzone Intradermal. This vaccine is for people between 18 and 64 years of age.

The typical flu shot is injected into the muscles of the arm. An intradermal vaccine uses smaller needles that enter just under the skin.

The needles are 90 percent smaller than those used for a typical flu shot. This may make the intradermal vaccine an attractive choice if you’re afraid of needles.

This method works just as well as the typical flu shot, but side effects are more common. These can include the following reactions at the site of the injection:

swelling
redness
roughness
itchiness

According to the CDC, some people who receive the intradermal vaccine may also experience:

headache
muscle aches
fatigue

These side effects should disappear within 3 to 7 days.

Nasal spray vaccine

If you meet the following three conditions, you may be eligible for the nasal spray form of the flu vaccine (LAIV FluMist):

You have no chronic medical conditions.
You aren’t pregnant.
You’re between 2 and 49 years of age.
You’re afraid of needles.

According to the CDC, the spray is nearly equivalent to the flu shot in its effectiveness.

However, certain individuals shouldn’t receive the flu vaccine in nasal spray form. According to the CDC, these individuals include:

children under 2 years old
adults over 50 years old
people with a history of allergic reactions to any ingredient in the vaccine
children under 17 receiving aspirin- or salicylate-containing medications
children 2 to 4 years old who have asthma or a history of wheezing in the past 12 months
people with weakened immune systems
people without a spleen or with a non-functioning spleen
pregnant women
people with an active leak between the cerebrospinal fluid and the mouth, nose, ear, or skull
people with cochlear implants
people who have taken flu antiviral drugs within the past 17 days

People who care for severely immunocompromised persons who require a protected environment should avoid contact with them for 7 days after receiving the nasal spray vaccine.

Anyone with these conditions is cautioned about taking the nasal spray vaccine:

asthma in people 5 years and older
underlying medical conditions with higher risk for flu complications
acute illness with or without fever
Guillain-Barré syndrome within 6 weeks following a previous dose of the flu vaccine

If your child is between the ages of 2 and 8 and has never received the flu vaccine, they should receive the nasal spray flu vaccine earlier. This is because they’ll need a second dose 4 weeks after the first.

Takeaway

A seasonal flu shot in early fall is the single best way to protect against the flu, especially when COVID-19 is still a risk. It’s possible to have both at the same time, so diligent care is required as flu season ramps up.

There’s no guarantee that getting a flu vaccine will prevent you from getting flu, but studies have shown that it can lessen the severity of the illness if acquired.

You can schedule an appointment to receive a flu shot at your doctor’s office or at a local clinic. Flu shots are widely available at pharmacies and grocery stores, with no appointment necessary.

Some facilities that previously offered flu vaccines, such as workplaces, may not due to closures from COVID-19. Call ahead if you’re unsure.