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COVID-19 Vaccine After Care: Pfizer-BioNTech and Moderna Vaccines

After receiving the COVID-19 vaccine, please remain in the clinic area for 15 minutes.

Serious side effects after receiving the vaccine are rare. However, should you develop any signs and symptoms that could be an allergic reaction soon after vaccination, seek medical attention right away from the clinic staff, or call 911 if you have left and are severely unwell.

Symptoms of an allergic reaction include:

  • Hives (bumps on the skin that are often very itchy).
  • Swelling of the face, tongue or throat.
  • Difficulty breathing.

Your health care provider will inform your local public health unit of any serious side effects after receiving your immunization. Reports of adverse reactions to vaccines are sent to Public Health Ontario and the Public Health Agency of Canada.

If you have any concerns or questions after your immunization, please call your local public health unit.

What should I expect in the next few days?

  • Similar to medications and other vaccines, the COVID-19 vaccine can cause some side effects, although not everyone will experience these. Most side effects are minor and don’t last very long.
  • Examples of some side effects associated with the COVID-19 vaccine may include pain at injection site, redness, swelling, tiredness, headache, muscle pain, chills, joint pain, and fever.
  • A cool damp cloth or covered ice pack on the area where the vaccine was given may help with soreness and if needed, medication such as acetaminophen or ibuprofen may be given for pain or fever.

Very common and common side effects

(may affect up to 1 in 10 people)

Uncommon side effects

(may affect up to 1 in 100 people)

  • Pain at injection site
  • Fatigue
  • Headache
  • Muscle pain
  • Chills
  • Joint pain
  • Fever
  • Diarrhea
Axillary swelling and tenderness (enlarged lymph nodes)
  • Pain at injection site
  • Fatigue
  • Headache
  • Muscle pain
  • Chills
  • Nausea / Vomiting
  • Axillary swelling and tenderness (enlarged lymph nodes)

Things to remember after you receive the vaccine

  • Continue to follow the recommendations of local public health officials to prevent spread of COVID-19, which include wearing a mask, staying at least 2 metres from others and limiting/avoiding contact with others outside your household.
  • Ensure you return for your second dose of the vaccine. If you receive your first dose at a community clinic, you will be provided with the date for your second dose appointment. If you receive your first dose elsewhere, follow the instructions of the health care provider to ensure you receive your second dose on time.
  • The second dose is required to build adequate immunity and provide protection against COVID-19.
  • Avoid receiving any other type of vaccine or TB skin test until at least 28 days after receiving either dose of COVID-19 vaccine.
  • This guidance provides basic information only. It is not intended to take the place of medical advice, diagnosis or treatment, legal advice or legal requirements.
  • Please check the Middlesex-London Health Unit and Ministry of Health (MOH) website for updates, information and other documents.
Date of creation: March 16, 2021
Last modified on: May 26, 2021


1BioNTech Manufacturing GmbH & Pfizer Canada ULC. (2020). Pfizer-BioNTech COVID-19 vaccine: COVID-19 mRNA vaccine, suspension for intramuscular injection [Product monograph]. Retrieved from
2Moderna Therapeutics Inc. (2020, December). Moderna COVID-19 vaccine mRNA-1273 SARS-CoV-2 vaccine: Suspension for intramuscular injection [Product monograph]. Retrieved from