Can I Get a Flu Shot While Sick?

Getting a flu shot is the best way to protect yourself against influenza A and B (the viruses that cause seasonal flu). But if you are already sick and headed to your vaccination appointment, you may want to call your provider to talk about whether or not you should postpone getting the flu shot until you are feeling better (or ask once you get there).

For the most part, if you have just a minor illness or cold, you can still get a flu vaccine. But if your case is more significant or you have a fever over 101 degrees F, your healthcare provider will likely recommend you wait.

Among the reasons for this is the fact that getting a flu shot when you're not well could prolong your recovery. And if you get a fever after your vaccination—a possible side effect—you won't know if it is a reaction to the vaccine or due to your illness. Furthermore, the benefit of getting your flu shot may actually be diminished.

reasons not to get a flu shot when you're sick
Illustrated by Cindy Chung, Verywell

Longer Recovery Time

When you get a flu vaccine (or any other type of vaccine) it triggers an immune response in your body. Your immune system develops antibodies against the influenza virus that is in the vaccine so that it will recognize it and be able to fight it off if you are exposed to it again in the daily life.

However, if you are sick when you are vaccinated, your immune system is already hard at work trying to fight the germs that have caused that illness. This means it will be harder for your body to develop antibodies to the flu virus at the same time. It could even mean that it will take longer for you to recover from your illness as your immune system tries to do double-duty.

Reduced Response to the Flu Vaccine

If your body is busy fighting off a different infection, it may not develop strong enough antibodies to the strains of influenza in the vaccine like it would if you were well. This could result in an increased chance that you could still get the flu.

Neither of these things is guaranteed to happen if you get the flu vaccine when you are sick, but they are possibilities.

When You Can Get the Flu Shot

The Centers for Disease Control and Prevention (CDC) recommends the annual flu vaccine for everyone over the age of 6 months with few exceptions.

For the most part, common, minor cold symptoms and a temperature of 100 degrees F or less do not prevent you from getting a flu vaccine.

If you are not dealing with a moderate to severe illness, you should have no problem with the vaccine and should not hold off. A cough, congestion, headache, and sore throat won't affect your body's response to the flu shot.

That said, if you want to get the nasal spray flu vaccine and you are congested, you may need to wait until your nose clears up so you have a better chance of getting the full benefit from that vaccine.

High-Risk Groups

There are certain groups of people that are considered to be at high risk for flu complications and should be vaccinated if at all possible. If you live with or care for someone in a high-risk group, it is equally important for you to be vaccinated to reduce the risk of spreading the flu.

Always speak to a provider before deciding to cancel a flu shot appointment due to illness. Particularly for you, the benefits of vaccination likely outweigh the above concerns.

Postponing Your Flu Shot

Having a cold isn't necessarily a reason to avoid getting your flu shot, but there are times when it may be advisable to put it off for a few days.

Your healthcare provider, nurse, or pharmacist that is administering the flu vaccine should ask you if you have a fever or are sick before giving it. However, if they do not, be sure to speak up or cancel your appointment if you are sick when it's time to get your vaccine.

If you have a fever over 101 degrees F or you are very ill, the CDC recommends waiting until your temperature has returned to normal and you feel better before being vaccinated.

Fortunately, fevers are not common with colds in adults, though they are a pretty common cold symptom in children. If you are planning on getting your child vaccinated, monitor their temperature if you think they are getting sick. If your child has a fever, the pediatrician may decide that it is better to wait until the fever has resolved before giving any vaccinations (influenza or others).

Reasons Not to Get a Flu Vaccine

Whether you are sick or note, some situations are considered either outright or possible contraindications for flu vaccination. Be sure to tell your practitioner if any apply to you or your child:

  • Under 6 months of age
  • History of a severe allergic reaction to a previous flu vaccine
  • History of Guillain-Barré syndrome after receiving a previous flu vaccine. (Talk to your healthcare provider to determine whether or not you should get the flu shot.)

Cold and Flu Doctor Discussion Guide

Get our printable guide for your next doctor's appointment to help you ask the right questions.

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Article Sources
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  1. Ohio State University. Buck MD Blog. Can I get the flu shot if I’m sick? What if I have a fever?

  2. U.S. Centers for Disease Control and Prevention. Who Should and Who Shouldn't Get a Flu Vaccine.

  3. U.S. Centers for Disease Control and Prevention. Live Attenuated Influenza Vaccine [LAIV] (The Nasal Spray Flu Vaccine).

  4. U.S. Centers for Disease Control and Prevention. Influenza (Flu) Vaccine: Addressing Common Questions about Influenza Vaccinations for Adults.

  5. U.S. Centers for Disease Control and Prevention. Flu Vaccine Safety Information.