April 8, 2021
What you need to know about Covid-19 vaccines
Many of us will be offered a Covid-19 vaccine soon. This fact sheet provides information about the vaccines so you can make an informed choice. No one can force you to get a Covid-19 vaccine. Medical doctors have made sure the following information is correct. Information is provided by the Occupational Health Clinics for Ontario Workers Inc. and the Ontario Fruit & Vegetable Growers' Association.

Key messages:

  • Four companies make the vaccines used in Canada now. More vaccines may be approved in the future. All will help protect you from getting Covid-19.
  • You need two doses (from the same company) for three of the vaccines. You need one dose for the Johnson & Johnson/Janssen Covid-19 vaccine.
  • The Covid-19 vaccines have been studied a lot in different groups of people. Health Canada approved them because they are considered safe and very effective.
  • You cannot get Covid-19 from the vaccine.

Why get a Covid-19 vaccine?

  • For many years, around the world we have used vaccines to protect people from deadly infectious illnesses, such as measles, tetanus, and polio.
  • Vaccines protect us from the virus, and help stop the virus from spreading to our families and communities. We also need to wear face coverings, wash hands, and stay at least two metres away from others. Fresh air and ventilation inside buildings are also important.

How effective are the vaccines?

  • So far, four vaccines are approved for use in Canada. They are made by Pfizer/BioNTech, Moderna, AstraZeneca/University of Oxford and Johnson & Johnson/Janssen.
  • All four vaccines were studied with thousands of people before being approved. All are very effective in preventing COVID-19 illness after getting the recommended doses.

How do the vaccines work?

  • Vaccines do not cure you. They help to prevent you from getting sick.
  • The vaccine teaches your body what the Covid-19 virus looks like. That way, you can fight the virus if it enters your body in the future.
  • The Pfizer and Moderna vaccines give instructions to your body (“mRNA”) to make spike proteins like those on top of the virus. These proteins do not make you sick. Your immune system then makes antibodies to fight the infection if the real virus does enter your body in the future. The Covid-19 vaccines do not affect your DNA.
  • The AstraZeneca and Johnson & Johnson/ Janssen Covid-19 vaccines use the harmless virus that causes the common cold. It delivers a spike protein like those on top of the virus. These proteins do not make you sick. They tell your body to build a strong immune response that can fight Covid-19 if the real virus does enter your body in the future.

Are there side effects?

  • The Covid-19 vaccines are considered very safe. People in the large scientific studies had normal reactions after vaccination. These reactions included things like pain where they got the needle, body and muscle pains, chills, and feeling tired or feverish. These are common side effects of vaccines and are not a risk to your health. They usually disappear in about a day. These symptoms may occur after each dose of the vaccine.
  • Like all vaccines, there is a very small chance of a more serious side effect, like an allergic reaction, but this is rare. You will be asked to stay after the vaccination for 15-30 minutes so medical staff can make sure you do not have an allergic reaction. Staff giving vaccines know how to treat allergic reactions.

Where can I learn more?

When Health Canada reviewed the available evidence, they found no major safety concerns. You can find their summary about the vaccines and other COVID-19 vaccine information in English and French at:  
These Canadian doctors checked the information in this bulletin:
Meb Rashid MD, Assistant Professor, University of Toronto; Vanessa Redditt, MD, Lecturer, University of Toronto; and Isaac I. Bogoch, MD, Associate Professor, University of Toronto

This resource is based on an original bulletin produced by: Refugee 613, Taibu Community Health Centre, OCASI, Women’s College Hospital, CASSA, PCHS, Chinese and Southeast Asian Legal Clinic CSALC and MCIS Language Solutions