Vaccine Health & Safety

The following information was developed for this website by medical professionals and public health experts using Canadian government and other scientific and medical sources. It is not intended as medical advice. Always seek the advice of a qualified healthcare provider with any questions you may have regarding the COVID-19 vaccine.

Last revision: 2021-08-13

If you are wondering whether you are eligible to receive the COVID-19 vaccine in your region, or want to book an appointment to get the COVID-19 vaccine, click on the link below to find the most up-to-date information and booking options for where you live.

British Columbia
New Brunswick
Nova Scotia
Newfoundland and Labrador
Prince Edward Island
Northwest Territories

The vaccines were developed quickly because the technology used to make them was already developed a few decades ago.  Many scientists around the world put all their efforts into creating safe and effective vaccines based on this existing technology because of the global crisis created by the pandemic, and the non-medical parts of approval (bureaucratic processes and rubber-stamping) were fast-tracked. No steps were skipped, and all safety procedures were followed.

Emergency approval was given quickly once trial results were available. The FDA is looking at giving mRNA vaccines full approval by fall of this year.

No. The protein used in the vaccine never interacts with or alters your DNA. It is naturally destroyed within hours of vaccination, leaving behind only the instructions on making antibodies if you ever get exposed to the COVID-19 virus.

Pfizer-BioNTech vaccine is approved by Health Canada for kids aged 12 and older.

The Moderna vaccine has been approved by Health Canada for use in individuals 18 years of age and above.

Studies are now underway to determine the safety and effectiveness of COVID-19 vaccines in younger children.

It’s extremely unlikely to get serious side effects that could cause long term health problems from COVID-19 vaccines. Historically, vaccine monitoring shows us that side effects usually happen within 6 weeks of getting a vaccine dose. And most vaccinations we have given historically have been in kids!

At this time in Canada, COVID-19 vaccines should not be given at the same time as other vaccines. However, in the U.S., COVID-19 vaccines and other vaccines may now be administered without regard to timing, including simultaneous administration of COVID-19 vaccines and other vaccines on the same day. You should discuss with your healthcare provider whether this is indicated for you.

Nearly everyone will be able to safely receive the vaccine, although a very small number of people may need to avoid vaccination due to severe allergies to parts of the vaccine. In the context of ongoing risk of COVID-19, most individuals can be offered vaccination. In fact, people with underlying health conditions that are clinically extremely vulnerable may be more prone to complications from COVID-19 infection and should get the vaccine as soon as it is available to them.

In general, it is safe for you to get the COVID-19 vaccine, even if you are recovering from an illness (e.g., shingles), but if you have a new illness preventing you from performing your regular activities, you should wait to get immunized until you have recovered. This will help to distinguish potential side effects of the vaccine from worsening of your other illness.‎ Also, waiting until you have recovered from an infectious illness ensures that you’re not putting others at risk of infection when you come for your vaccine. 

If you have symptoms of COVID-19, you should stay home and get tested.

Nearly everyone will be able to safely receive the vaccine. There are no significant concerns about safety for those with weakened immune systems or auto-immune disease. It is possible that the vaccine may not work as expected in people who have a weakened immune system. If you have questions and have a weakened immune system or auto-immune disease, speak to your healthcare provider about COVID-19 vaccines.

Menstruation is a complex process, and can be influenced by many things, such as environmental changes, stress, sleep and some medications. The lining of the uterus is in fact considered to be an active part of the immune system. When your immune system is working hard because you’re vaccinated or sick, you may experience changes in how the endometrium reacts. In this way it is possible that the vaccine affects menstruation somehow.

But, one thing to keep in mind is that anytime you look at a large group of people, there will always be some people experiencing changes in their menstrual cycle. With hundreds of millions of vaccines being given worldwide, there will be some people who experience changes in their menstrual cycle too. Researchers are confident that the vaccine is safe, and that there is not enough data to suggest that there should be concerns over potential changes to the menstrual cycle.

The COVID-19 vaccine is not shed after vaccination, so being around recently vaccinated individuals would not be expected to affect someone’s cycle either.

Any changes you experience in your menstrual cycle after getting the vaccine are temporary, so it shouldn’t be a reason not to get a shot. However, women with concerns should speak with their doctor since cycles can be delayed for other reasons as well.

Pregnancy itself puts women at higher risk of severe COVID-19. They are more likely to develop respiratory complications requiring intensive care, more likely to have a premature birth and caesarean delivery, and their babies are more likely to be admitted to a neonatal unit.

The Canadian Society of Obstetrics and Gynecology (SOGC), the National Advisory Committee on Immunization, and public health experts in Canada all advise that women who are pregnant or breastfeeding should be prioritized and offered vaccination at any time (in any trimester) during pregnancy and during breastfeeding if they are eligible and no contraindications exist.

Both pregnant vaccinated women, and newborns after a vaccinated woman delivers, have detectable levels of protective antibodies against COVID-19. Studies also show that antibodies are transmitted in breast milk to babies as early as 7 days after mother is vaccinated.​​ This protects the baby as well.

If you have questions, and you are pregnant, planning to become pregnant or are breastfeeding, speak to your health care provider about COVID-19 vaccines.

There is no evidence that any vaccine, including the COVID-19 vaccine, affects fertility in either women or men. 

Lipid particles from the mRNA vaccines do not accumulate in the ovaries.

COVID-19 vaccination before conception does not affect implantation of an embryo.

Someone who is vaccinated against COVID-19 cannot shed virus or other substance to make another person infertile or affect their pregnancy.

The vaccines have no impact on male fertility. In fact, men who get infected with COVID-19 have a higher chance of problems with erectile dysfunction, producing less sperm or getting testicular infections. 

There are very few reasons someone should not get the COVID-19 vaccine.

You should not get the vaccine if you:

1. Have serious allergies to any of the ingredients in the vaccines: an ingredient in the mRNA vaccines that have been associated with a rare but serious allergy (anaphylaxis) is polyethylene glycol (PEG), which can be found in some cosmetics, skincare products, laxatives, some processed foods and drinks and other products. Note: PEG is not in the AstraZeneca vaccine and Johnson & Johnson vaccines. An ingredient in the AstraZeneca and Johnson & Johnson vaccines that has been associated with a rare but serious allergy is Polysorbate 80 – It is also found in medical preparations (e.g., vitamin oils, tablets and anticancer agents) and cosmetics.

2. Have had a life-threatening reaction to a previous dose of the COVID-19 vaccine or to any part of the vaccine.

Talk to your health care provider if you have had an anaphylactic reaction but do not know the cause. Serious, life-threatening allergic reactions to vaccines (anaphylaxis) are extremely rare – much rarer than people think. Anaphylaxis is preventable in many cases and treatable in all cases. All immunizing healthcare providers in Canada are required to be trained and actively watch for and treat anaphylaxis immediately. Rarely, based on the recommendations of an allergist and Medical Health Officer, a person may receive a vaccine in a hospital setting.

It is not recommended that you drink alcohol or come drunk to your vaccination appointment. This is not because of a vaccine safety concern (that alcohol interferes with the vaccine) but because the healthcare provider needs your informed consent before giving vaccines. Alcohol may impair (lessen) your ability to fully understand the health information and ask questions.

There are no studies around alcohol use and the effectiveness of the COVID-19 vaccines. People who struggle with alcohol use disorder (AUD) may have a compromised (weaker) immune system and should talk to their healthcare provider. Expert opinion is that we do not expect a moderate amount of alcohol use will have a negative effect on the immune response to the vaccine.

If you use cannabis, the COVID-19 vaccine is safe for you.

When it’s time for your appointment though, we recommend that you are not high. This is not because of a vaccine safety concern (that marijuana interferes with the vaccine) but because the healthcare provider needs your informed consent before giving vaccines. Marijuana may impair (lessen) your ability to fully understand the health information and ask questions.

There are no studies around cannabis use and the effectiveness of the COVID-19 vaccines. There is emerging evidence suggesting that cannabis smoking can have negative consequences on a person’s respiratory system and immune competence so it is even more important to get a COVID-19 vaccine to protect yourself from the virus if you smoke.