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Immunization after care

It is common to experience side effects to immunizations. They usually occur within 12–24 hours after immunization and go away within a few days.

Common side effects

Some people may feel mild discomfort after getting a shot. This may last 1 to 2 days. Common reactions include:

  • Soreness, redness, and swelling at the injection site

  • A fever 1-2 days after the shot

  • MMR or chickenpox vaccine: a fever, rash or both may appear up to several weeks after the shot

Check body temperature

A fever is a very common reaction. To measure your child's temperature:

  • Have your child remain calm

  • Use their armpit

  • Use digital thermometers rather than glass thermometers or fever strips

  • Check their temperature every 4 hours

Treating a fever

All fever (Low fever starts at 37.4°C)

  • Take most clothes off or dress lightly

  • Do not wrap your child in a blanket

  • Keep the room cool, use a fan

  • Give plenty of fluids to drink

Fever over 38°C

  • In addition to the treatment for all fever, give fever medicine: acetaminophen (e.g. Tylenol) or ibuprofen (e.g. Children's Advil or Motrin) as per the directions on the package

High fever (39°C or higher)

  • Call or go to your doctor and treat the fever with all of the above while waiting.

Seeking medical attention

These problems are very rare after immunization, but if they happen, it's important to take action.

Call 9-1-1 immediately if you see:

  • Trouble breathing or swallowing

  • Swelling on face of lips, or tongue gets bigger

Get to a doctor immediately if your child has any of the following:

  • High fever (39°C/102.2°F or higher)

  • Weakness and looks pale or sick

  • Increased sleepiness and does not wake to eat

  • Crying for more than 3 hours

  • A strange cry, different than their normal cry

  • Hives (raised red or pink spots of different sizes on skin)

  • Seizure or convulsions (shaking, twitching or jerking motions of the body)

  • Swollen abdomen, vomiting often, bloody stools

  • A fever for more than 48 hours

If you have any questions or concerns, contact your family doctor, your local community health centre, or HealthLink BC by calling 8-1-1, available 24 hours a day.


Visit the get immunization section on the Sneezes & Diseases website for the latest immunization news and resources. 

SOURCE: Immunization after care ( )
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