A person can get the flu shot when sick with mild illnesses, such as colds and sinus infections. However, a doctor may recommend delaying the shot in some instances.

The influenza virus — which causes flu — can have serious complications, especially for older adults, young children, and individuals with certain medical conditions. According to the Centers for Disease Control and Prevention (CDC), getting the flu shot is the best way to prevent getting the flu and spreading it to others.

A person always needs to consult a doctor to address concerns before taking the flu shot.

This article explains how flu shots work, how illness may affect their effectiveness, and when to avoid it.

a person is receiving a flu shot in a clinicShare on Pinterest
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Generally, a person can still receive a flu shot if they have a mild illness. The CDC advises people with a mild illness to speak with their doctor about their symptoms before taking the flu shot.

Sometimes, a person may need to recover before receiving the flu shot.

The flu shot is a type of vaccine that helps the body stimulate a protective immune response to the flu virus. Flu shots, in particular, are inactivated vaccines containing dead flu viruses. Once a person receives the injection, their body trains the immune system to detect the flu virus as if it were alive so that it produces antibodies.

Antibodies can recognize and fight against the flu virus. This means that if the virus passes to a vaccinated individual, their antibodies become activated, helping prevent infection or reduce the severity of flu symptoms.

Although vaccinated people may still get the flu, it will likely be less severe. Getting a flu shot is important, especially for people with cancer or untreated HIV.

Learn more about the benefits of taking the flu shot.

The CDC advises that it is still safe to get the flu shot even when a person has milder illnesses or the following symptoms:

Getting the flu shot in September or October also ensures better protection throughout the flu season.

Learn more about flu shot safety.

Some people need to avoid getting the flu shot, including those who:

  • are under the age of 6 months
  • have had a severe or life threatening reaction to the flu vaccine or any of its ingredients
  • have experienced a prior severe allergic reaction to the flu shot

A person needs to consult a doctor for any safety concerns before having the vaccine, especially if they have a severe egg allergy or have experienced Guillain-Barré syndrome. Different formulations exist, and a doctor can advise on the best option.

People with long-term health conditions, including asthma, diabetes, and heart disease, are at high risk for flu complications. They need to get the flu shot to reduce the risk of further problems.

Some high risk groups include:

  • children under 5 years old
  • people aged 65 years and older
  • pregnant people

Learn more about flu complications.

During the colder months, flu cases begin to rise. Getting the flu shot every year is an important way for people to protect themselves from becoming ill with the flu.

A person can still get the flu vaccine if they have a mild illness, such as a cold or sinus infection. Still, if someone is unwell and due to receive the flu vaccine, they need to speak with a doctor. Sometimes, individuals may have to postpone vaccination until they recover.

If an individual is undecided about getting the flu shot, they can consult a doctor about their symptoms or concerns.