Can I get a flu shot while I'm sick?


The flu vaccine is the best way to protect against flu A and B. These are the viruses that cause seasonal flu.

But if you do get sick when your appointment is scheduled, ask your doctor if you should postpone your vaccination until you feel better.

If you get a mild illness, like a cold, you can still get a flu shot. If you are sick or have a fever, your doctor will likely recommend that you wait.

This article explains the potential problems with getting the flu shot when you are sick, when is the best time to get vaccinated, and why some people should avoid it altogether.

Get Medical Information / Cindy Chang


Vaccines trigger an immune response in your body. Is that how it works:

  • The vaccine "shows" the virus to your immune system.
  • Your immune system produces antibodies, which are proteins that attack the virus and inactivate it.
  • Then your body can respond more quickly to a future flu infection.
  • Such a quick response can save you from illness.

If you get sick during the vaccination, your immune system is already working hard to fight another disease. This means that you may not have the resources to make flu antibodies at the same time. Therefore, the vaccine may be less effective in preventing influenza.

The injection can also slow your recovery from another illness because your immune system is dividing its resources.


The flu shot while you are sick divides the resources of your immune system. This can prolong your illness and reduce the effectiveness of the flu vaccine.

When to delay a shot

Cold symptoms are not necessarily a reason not to get the flu shot. But sometimes it's better to put it off for a few days.

The Centers for Disease Control and Prevention (CDC) recommends waiting until you feel better if:

  • It has a temperature of over 101 degrees Fahrenheit.
  • You are very sick

In adults, fever is not a common symptom of a cold. However, it is more common in children.

If you plan to vaccinate your child and he appears to be ill, monitor his temperature. If they have a fever, the doctor may decide that it is better to wait than to get vaccinated right away.

The provider who gives you the vaccine should ask if you have a fever or are sick before doing so. If not, be sure to report it.

When not to wait

CDC recommends getting an annual flu vaccine for everyone over 6 months of age , with a few exceptions .

Unless you are dealing with a moderate to severe illness, you should have no problems with the vaccine and should not put it off. Cough, runny nose, headache, and sore throat will not affect your body's response to the flu shot.

Another thing is the nasal spray flu vaccine . If you have a stuffy nose, you may need to wait until your sinuses clear. Otherwise, you run the risk of not getting the full benefit of the vaccine.

High risk groups

Certain groups of people are at high risk for complications from influenza and should be vaccinated if possible. If you're at high risk, living with, or caring for someone at risk, it's especially important to get vaccinated as soon as possible.

High-risk groups include:

  • Babies and toddlers
  • Anyone who is pregnant or has recently given birth.
  • Everyone over 65
  • People with chronic medical conditions like heart, lung, and diabetes.

Be sure to talk to your doctor before you stop getting a flu shot due to illness. Depending on your risk, the benefits of vaccination may outweigh the worries.


A mild illness, such as a cold, does not require postponing the flu shot. If you are at high risk for complications from the flu, do not stop or delay vaccinations due to illness unless advised to do so by your healthcare provider.

Who shouldn't get a flu shot?

Some people should not get a flu shot, regardless of whether they are currently sick. Be sure to tell your doctor if any of this applies to you or your child:

  • Less than 6 months
  • Severe Allergic Reaction Before Flu Vaccine
  • If you have ever had Guillain-Barré syndrome (a disease in which the immune system damages the nerves).

In these situations, talk to your healthcare provider about whether the flu vaccine is safe for you.

Cold and Flu Discussion Guide

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


Getting the flu shot when you are sick means sharing the focus of your immune system. This can reduce the effectiveness of the vaccine and prolong the illness.

You do not need to delay getting a flu shot due to mild illness. If you are at high risk for complications from the flu, talk to your doctor before canceling or postponing vaccinations.

The flu vaccine may not be safe for people with an egg allergy or for people who have had severe reactions to the vaccine in the past. Talk to your doctor about whether you should get vaccinated.

Frequently asked questions

  • No, but it may take you longer to recover from a cold because then your body needs to fight the existing illness and make antibodies against the flu. If you have severe symptoms, wait until you recover to get the vaccine.

  • No. While one study showed an increased risk, subsequent research found flaws in this study and determined that there was no link between flu vaccination and COVID risk. The flu vaccine can even help protect against COVID.

  • Yes. A flu shot is still recommended if you are allergic to eggs, but your doctor may recommend that you get vaccinated under medical supervision at a hospital. However, if you have ever had an allergic reaction to a flu shot, it is recommended that you not get vaccinated again.

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