COVID-19 Vaccine Facts

This helpful video answers a number of common questions about the COVID-19 vaccines. Questions with time stamps are listed in the tab below the video.

COVID-19 Vaccine Questions

• 1:10 - Why get vaccinated?
• 1:41 - How do mRNA vaccines, like the COVID-19 vaccines, work?
• 2:42 - Can the mRNA vaccines alter a person's DNA?
• 3:18 - Can the COVID-19 vaccines cause a COVID-19 infection?
• 3:52 - Once a person is fully vaccinated, can they stop following public health measures, like wearing a mask, physical distancing and self-isolating when they become sick?
• 5:00 - Can the COVID-19 vaccines cause a false COVID-19 viral test?
• 5:48 - How many doses are required for the vaccine to be effective?
• 6:01 - What are the side effects of the COVID-19 vaccines?
• 6:36 - If a person develops an unusual side effect to the vaccines, what should they do?
• 7:30 - Can people with severe allergies to a component of the COVID-19 vaccines still receive the vaccine?
• 8:18 - Can people with severe allergies to other vaccines, medicines or foods receive the COVID-19 vaccine?
• 8:41 - Who should NOT be vaccinated at the current time because of lack of information from clinical trials?
• 9:24 - Are there any other precautions with receiving the vaccine?
• 9:52 - Can people who have been diagnosed with COVID-19 be vaccinated?
• 10:30 - How was Health Canada able to approve the COVID-19 vaccines so quickly? Did they lower their safety standards?

Currently, the COVID-19 vaccines fully approved by Health Canada include:

• Pfizer-BioNTech and Moderna (which use mRNA technology)
• AstraZeneca and Janssen (Johnson & Johnson) (which use viral vector-based technology)

Several other vaccines are currently under the process of approval by Health Canada.

The Pfizer-BioNTech and Moderna vaccines were developed using a technology called messenger RNA or mRNA. This type of vaccine development does not use the live virus that causes COVID-19.

When the body is exposed to an mRNA vaccine, the vaccine teaches the cells how to make a protein - or even just a piece of a protein - that triggers an immune response inside our bodies. The cells recognize that these proteins are foreign and produce antibodies to protects us from getting infected if the real virus enters the body in the future.

Viral vector-based vaccines use a harmless virus, called the “vector” virus, as a delivery system. This “vector” virus is not the virus that causes COVID-19 - it is among the viruses that can cause the common cold.

When the body is exposed to a viral vector-based vaccine, the vector virus contained within the vaccine produces a spike protein found on the surface of the virus that causes COVID-19. The cells recognize that these proteins are foreign and produce antibodies to protect us from getting infected if the real virus enters the body in the future.

Vaccine approval in Canada happens in phases (exploratory, preclinical, clinical trials, application, scientific review, approval). Health Canada will only approve a vaccine if it supported by strong data and evidence. After approval, vaccines can be distributed and given. 

For COVID-19 vaccines, Health Canada was using a fast-tracked scientific review process that allowed manufacturers to submit data as it became available, so Health Canada experts could start the review process right away. Vaccines were only authorized once all necessary evidence was available.

As of September 16, 2021, four vaccines are fully approved by Health Canada; Pfizer-BioNTech Comirnaty, Moderna Spikevax, AstraZeneca Vaxzevria and Janssen (Johnson & Johnson).

An infographic that explains vaccine development and approval in Canada is available. 

Health Canada only approves a vaccine after a thorough review process. The safety requirements in clinical trials for the COVID-19 vaccine were just as strict as the process for any other vaccine. 

The development of vaccines for COVID-19 progressed quickly for many reasons, including:

• Reduced time delays in the vaccine approval process, due to an interim order pathway for COVID-19-related drugs and vaccines being put in place. This is a tool used during public health emergencies. It ensures timely access to vaccines and medications that have demonstrated the ability to diagnose, prevent, treat or cure COVID-19. The interim order pathway allows companies to submit information for approval as it becomes available, rather than having to wait and submit everything at the end. The steps to approval remain the same.
• Quick adaptation of existing research programs, such as those focusing on mRNA- and viral-vector-based technologies.
• Global collaboration between scientists, health professionals, researchers, industry and governments.
• Increased dedicated funding.
• Quick recruitment of participants for clinical trials.
• Quick set-up of clinical trials to show the effectiveness of the vaccines.

The Public Health Agency of Canada monitors the ongoing safety and effectiveness of all approved vaccines, including the COVID-19 vaccines. In Ontario, all reported adverse events following immunization (AEFI) are tracked and made public. Once the product is on the market, the manufacturers are legally required to submit reports of adverse events to Health Canada.

Current evidence shows all of the COVID-19 vaccines approved for use in Canada are able to prevent mild and moderate cases of COVID-19 and are very effective in preventing hospitalizations and death, including against known variants of concern (VOC). A full vaccine series significantly improves protection against infection and severe cases of COVID-19 compared to only one dose. Read more about the variants of concern on the Frequently Asked Questions page.

Recent Ontario data also indicates that Pfizer, Moderna, and AstraZeneca vaccines provide a high degree of protection against the Delta variant, particularly for preventing hospitalization or death (VE: 78 to 96%) resulting from this VOC.

Research is ongoing and updates will be provided as they are available. For more on real world vaccine effectiveness, see COVID-19 Real-World Vaccine Effectiveness – What We Know So Far from Public Health Ontario.

Getting vaccinated against COVID-19 is one of the best ways to protect yourself and those around you; but it's not the only way. After getting vaccinated, it is still important to take steps to protect yourself, your loved ones and our community against COVID-19.

After getting vaccinated, it takes time for the body to build up immunity to the virus so protection is not immediate. Studies are also still underway to determine the effectiveness of the vaccines in preventing asymptomatic infection and reducing the transmission of COVID-19.

For now, and until scientific experts say it’s safe to stop, it is important for everyone, even those who are fully vaccinated, to continue to follow the advice of public health officials. This includes following all public health measures, like staying home when sick, keeping 2 metres distance from others, wearing your mask and washing your hands often. It also means self-isolating and getting tested if you develop any symptoms. Learn more about things you can do to reduce virus spread.

The COVID-19 vaccine cannot give you COVID-19 or any other infectious disease. None of the Health Canada approved vaccines so far are live vaccines, meaning that they do not contain the virus that causes COVID-19.

It is important to remember that it typically takes a few weeks for the human body to build immunity after vaccination. That means it is possible for a person to become infected with the virus that causes COVID-19 just before or just after vaccination. This is because the vaccine has not had enough time to provide protection. Even if you receive the vaccine, please continue to follow the public health measures to keep you, your loved ones and your community safe.

Messenger RNA (mRNA) is not able to alter or modify a person’s genetic makeup (DNA). The mRNA from a COVID-19 vaccine never enters the nucleus of the cell, which is where our DNA are kept. This means the mRNA does not affect or interact with our DNA in any way. Instead, COVID-19 vaccines that use mRNA work with the body’s natural defenses to safely develop protection (immunity) to disease.

Ingredients in the currently approved COVID-19 vaccines can be found on the Government of Canada webpages:

• Pfizer-BioNTech Vaccine 
• Moderna Vaccine
• AstraZeneca Vaccine
• Janssen (Johnson & Johnson) Vaccine

The side effects of the COVID-19 vaccines are similar to those of other vaccines. They are mostly mild or moderate and usually go away within a few days after immunization. Common side effects include things like pain at the injection site, body chills, feeling tired, and feeling feverish. These types of side effects are expected and simply indicate the vaccine is working to produce protection.

As with all vaccines, there is a chance that there will be a serious side effect, but these are rare. However, should you develop any of the following reactions within three days of receiving the vaccine, seek medical attention right away or call 911:

• hives
• swelling of the face or mouth
• trouble breathing
• very pale colour and serious drowsiness
• high fever (over 40°C)
• convulsions or seizures
• other serious symptoms (e.g. “pins and needles” or numbness)

If you are concerned about any reactions you experience after receiving the vaccine, contact your healthcare provider, who can assess and report it if necessary. 

If you still need to receive your second dose, tell the person providing the second dose about any side effects you experienced following the first dose.

As with any medicines and vaccines, allergic reactions are rare but can occur after receiving a vaccine. Symptoms of an allergic reaction include hives (bumps on the skin that are often very itchy), swelling of your face, tongue or throat, or difficulty breathing.

Most serious reactions will occur shortly after injection, and clinic staff are prepared to manage an allergic reaction should it occur. If you are concerned about any reactions you experience after receiving the vaccine, contact your health care provider. 

Allergic reactions to the vaccine components are possible. The components of each vaccine are available: 

• Pfizer-BioNTech Vaccine
• Moderna Vaccine
• AstraZeneca Vaccine
• Janssen (Johnson & Johnson) Vaccine

Safe and reliable vaccines can help protect you and your family from COVID-19. Vaccines help to build up your immunity to the virus, so your body will fight it off more easily if you are exposed to it. This can reduce your risk of developing COVID-19, can make your symptoms milder if you do get it, and will help prevent serious illness and death as a result of COVID-19 infection.

COVID-19 vaccines are an important tool to help stop the spread of the virus, build immunity in individuals and communities and allow us to safely resume normal life. When a large percentage of the population becomes immune to COVID-19, the spread of the virus will slow down or stop. This is called 'herd immunity' or 'community immunity'.

• The percentage of people who need to be immune for it to be considered community immunity is different for each disease. For example, 80% of the population must be immune to polio but 95% must be immune to measles for community immunity.
• More research is needed to find out what percentage of people need to be vaccinated to achieve community immunity for COVID-19. 

The COVID-19 vaccine is a safe way to increase your immunity to COVID-19 infection.

COVID-19 is highly contagious and can result in serious illness. By not getting vaccinated, you are putting yourself at greater risk of getting infected with COVID-19 and as a result, the potential to get seriously or critically ill. You are also putting other community members at risk who may be at higher risk of severe illness due to COVID-19 or who can’t get vaccinated. 

When enough people are vaccinated against a certain illness, the germs that make people sick can’t travel as easily from person to person creating “community immunity”. 

With community immunity, fewer people get sick because there are fewer germs moving around from person to person. Those who CAN’T get vaccinated will also have some protection from getting sick, because there are fewer germs being spread. So the vaccine is not only protecting the individual, it is also protecting the community.

The more people that can be vaccinated against an illness like COVID-19, the safer our entire community will be, including those who are at highest risk.

Those who have previously had PCR-confirmed infection should still be vaccinated. Individuals do not need COVID-19 testing prior to vaccination. Due to the severe health risks associated with COVID-19 and the fact that re-infection with COVID-19 is possible, people can still get a COVID-19 vaccine even if they have been sick with COVID-19 before.

It is important to ensure you have recovered and public health has cleared you from isolation prior to visiting a vaccination clinic. Having tested positive may provide you with short term protection, but it is important to still get the vaccine as it is not known how long immunity after infection lasts and you could get infected again.

TBDHU can provide the COVID-19 vaccine to those without an OHIP or Ontario Health Card. Please call (807) 625-5900 or toll-free at 1-888-294-6630 to make a COVID-19 vaccination appointment.

The COVID-19 vaccines are not suggested for individuals who are very ill (as a precautionary measure).

Vaccination should also be delayed in those with symptoms of COVID-19 and those with confirmed or suspected COVID-19 infection.

You should receive an email with a link to your vaccination receipts. They can also be accessed through the COVID-19 Vaccination website (not accessible using Internet Explorer):

• Scroll to the bottom of the page and if you read, understand and accept the terms of use, click “Continue”.
• Complete the Identity Verification Information and click “Continue”.
• Click “Continue” in the yellow box titled “Vaccination Receipts”.
• You will now be able to review your results and access a PDF receipt.

Certain populations were not included in the clinical trials for the currently approved COVID-19 vaccines, or had very small representation, but are now encouraged to get their COVID-19 vaccination:

• Pregnant individuals (more information in tab below).
• Individuals who are breastfeeding (more information in tab below).
• Immunocompromised persons (due to disease or treatment).
• Those with an autoimmune condition.
• Individuals 12 to 24 years of age (more information in the tabs below).

There are some people in these groups who may not be able to receive the vaccine if the individual and a health care provider determine that the risks of vaccine outweigh the benefits for the individual. See more in the tabs below.

Individuals with allergies/anaphylaxis to a previous dose or any vaccine ingredients should consult a health care provider.

For Additional Information

• COVID-19 Vaccination Recommendations for Special Populations

All pregnant or trying to get pregnant individuals are eligible and recommended to be vaccinated as soon as possible. COVID-19 vaccines are recommended, at any stage in pregnancy (including first trimester), as COVID-19 infection during pregnancy can be severe, and the benefits of vaccination outweigh the risks. 

It is recommended, but not required, that pregnant individuals have a discussion with their treating health care provider, or with a health care provider familiar with their pregnancy, that includes:

• a review of the potential risks and benefits of the vaccine, 
• a review of the risk of acquiring a COVID-19 infection during pregnancy,
• a review of the potential risks /consequences associated with a COVID-19 infection during pregnancy, and
• an acknowledgment of the limited evidence from clinical trials of COVID-19 vaccines in the pregnant population.   

The COVID-19 Vaccination in Pregnancy & Breastfeeding Patient Decision-Making Tool can be used by individuals to help make their decision about COVID-19 vaccination.

Please Note:

• A letter from a health care provider is not required for vaccination. 

For Additional Information

• COVID-19 Vaccination in Pregnancy & Breastfeeding Decision-Making Support Tool (PDF) - Ontario Ministry of Health
• Society of Obstetricians and Gynaecologists of Canada Statement on COVID-19 Vaccination in Pregnancy. (PDF)
• COVID-19 Vaccination Recommendations for Special Populations (PDF) - Ontario Ministry of Health
• BORN: COVID-19 Immunizations and Pregnancy (various languages available)
• COVID-19 Guidance: Labour, Delivery and Newborn Care (PDF) - Ontario Ministry of Health
• COVID-19 Vaccine Information - Provincial Council for Maternal and Child Health

The vaccines are safe for the breastfeeding person, and should be offered to those eligible for vaccination. Recent data shows that mRNA from vaccines do not transfer into breast milk. Anti-COVID-19 antibodies produced by the breastfeeding person have also been shown to transfer through breast milk and provide protection to the infant. 

For Additional Information

• COVID-19 Vaccination in Pregnancy & Breastfeeding Decision-Making Support Tool (PDF) - Ontario Ministry of Health
• COVID-19 Vaccination Recommendations for Special Populations (PDF) - Ontario Ministry of Health
• COVID-19 Guidance: Labour, Delivery and Newborn Care (PDF) - Ontario Ministry of Health
• COVID-19 Vaccine Information - Provincial Council for Maternal and Child Health

On May 5, 2021, Health Canada authorized the use of the Pfizer-BioNTech COVID-19 vaccine in children 12 to 15 years of age and they are now eligible to receive a vaccine in Ontario. Individuals turning 12 in 2021 (i.e. born in 2009) are also eligible in Ontario. See the COVID-19 Vaccine Appointments page for more information on how to make an appointment.

The authorized ages are 12 years of age and older for the Pfizer-BioNTech COVID-19 vaccine and 18 years of age and older for the Moderna, AstraZeneca and Janssen (Johnson & Johnson) COVID-19 vaccines.

Important Resources for Additional Information

• COVID-19 Vaccine Information Sheet for Youth (Aged 12-17)
• What youth need to know about their COVID-19 vaccine appointment
• Child and Youth COVID-19 Vaccine Fact Sheet
• COVID-19 Vaccines for Ontario Youth - Children's COVID-19 Vaccine Advisory Table
• The Safety and Efficacy of COVID-19 Vaccines for Youth - Government of Ontario
• COVID-19 Vaccines for Youth - Government of Ontario

Vaccination Pain Management Resources

• CARD System Handout: Coping with Pain and Fear around Vaccination for Teens - SickKids
• Needle pokes: Reducing pain with comfort positions and distraction - SickKids

Out of an abundance of caution, the Ontario Ministry of Health is recommending that individuals aged 18 to 24 be immunized with the Pfizer-BioNTech vaccine. This is due to an observed increase in Ontario of the very rare heart condition called pericarditis/myocarditis following vaccination with Moderna compared to Pfizer in this age group, particularly among males.  

Individuals who received Moderna for their first dose can safely take the Pfizer-BioNTech vaccine for their second dose. Mixing vaccines is safe and effective, and full vaccination with two doses of the mRNA vaccine offers the greatest protection you can have against COVID-19 and the Delta variant.

All individuals 18 to 24 who choose to receive Moderna must provide informed consent and understand the increased risk of myocarditis/pericarditis for their age group. 

Vaccination is highly recommended; the benefits of vaccination outweigh the potential risks.

Percarditis/Myocarditis

Myocarditis/pericarditis following COVID-19 mRNA vaccines remains rare, even among the age groups with the highest observed rates of this event, and COVID-19 vaccines continue to be recommended to prevent COVID-19 disease, which also includes a risk of myocarditis. 

A small number of cases of myocarditis and pericarditis have been identified in Ontario. The majority of these reported cases have been mild with individuals recovering quickly, normally with anti-inflammatory medication. Symptoms have typically been reported to start within one week after vaccination, more commonly after the second dose.

Please seek medical attention if any of the following symptoms of myocarditis/pericarditis develop after receiving the vaccine: 

• chest pain or feelings of tightness
• shortness of breath
• heart palpitations (pounding or racing heart)
• feeling of a rapid or abnormal heart rhythm

As a precaution, individuals who experienced the rare myocarditis and/or pericarditis after a first dose of an mRNA vaccine (Public Health Agency of Canada) should wait to get their second dose until more information is available.

All vaccines used in Ontario have been approved by Health Canada and are safe and effective. 

So far, a vaccine has not been approved for children under the age of 12. Work is underway, specifically in the 5 - 11 year old range, to determine when those under the authorized ages can receive the vaccine. 

Individuals turning 12 in 2021 (i.e. born in 2009) are now eligible in Ontario. See the COVID-19 Vaccine Appointments page for more information on how to make an appointment.

The authorized ages are 12 years of age and older for the Pfizer-BioNTech COVID-19 vaccine and 18 years of age and older for the Moderna, AstraZeneca and Janssen (Johnson & Johnson) COVID-19 vaccines.

• The Ontario Ministry of Health provided a news release on May 21, 2021 noting that second doses of the AstraZeneca vaccine will once again be administered. As of June 12, 2021, Ontario accelerated the second dose interval for those who received a first dose of AstraZeneca to eight weeks with informed consent, from 12 weeks. See the media release for details.
• Current evidence recommends waiting 12 weeks to receive a second dose as this interval allows for a better/optimal immune response to be achieved. However, the province recognizes that some may want to receive their second dose sooner to have the increased protection provided by an earlier second dose.
• Individuals who received the AstraZeneca vaccine for their first dose can choose whether they would like to receive the AstraZeneca vaccine or an mRNA vaccine (Pfizer-BioNTech or Moderna) for their second dose.
  • Review the Ministry of Health's COVID-19 Vaccine Information for Individuals who receive a first dose of AstraZeneca to help you to decide what choice is right for you. You can also have a discussion with a health care provider.
  • See the Individuals who Received the AstraZeneca Vaccine section for more information and details on how to book a second dose appointment.
• If you have received the AstraZeneca vaccine within the last 4-28 days and are experiencing new symptoms, please contact a health care provider for further assessment. If you are experiencing any of the following symptoms, go to the emergency department right away and tell them you have recently received an AstraZeneca vaccine:
  • severe headache that does not go away
  • seizure
  • difficulty moving part of your body
  • new blurry or double vision that does not go away
  • difficulty speaking
  • shortness of breath
  • severe chest, back or abdominal pain
  • unusual bleeding or bruising
  • new reddish or purplish spots or blood blisters
  • new severe swelling, pain or colour change of an arm or leg
• Data out of the UK shows a dramatically reduced risk of serious adverse events in second doses of AstraZeneca. 

If you received a partial or complete COVID-19 vaccine series (e.g. one or both doses) outside of Ontario, it is possible to have this recorded in COVaxON, Ontario’s provincial system to record COVID-19 vaccination. However, only public health units can enter this information; pharmacies and primary care offices do not have the ability to do so.

At this time, proof of immunization from the place where you were immunized, (such as a receipt, card or certificate), is needed before the TBDHU can create a record and record your vaccination. Currently, you can provide proof via:

• Email: Please send an email to vaccines@tbdhu.com. You will receive a reply with instructions on how to safely and securely email your proof of immunization.
• Fax: (807) 625-4828
• Mail: Vaccine Preventable Disease Program, Thunder Bay District Health Unit, 999 Balmoral Street, Thunder Bay, ON, P7B 6E7
• Drop off: Drop off a copy to your nearest TBDHU office. Please note that you must provide a copy to the TBDHU; our staff cannot make copies at this time.

In Canada, the following COVID-19 vaccines are currently authorized by Health Canada: Pfizer-BioNTech, Moderna, AstraZeneca/COVIDSHIELD and Janssen/Johnson & Johnson. Second doses for all those who received a first COVID-19 vaccine dose outside of Ontario or Canada should follow the interval recommended by Ontario, which is currently 28 days since the first dose was given.

Individuals who received a COVID-19 vaccine that has not been approved in Canada should follow up with their health care provider or the Thunder Bay District Health Unit for next steps regarding immunization. There is some guidance in the tab below, you can contact the Vaccine Preventable Disease program by calling (807) 625-5900 or toll-free at 1-888-294-6630 (extension 5108 or press 4 on the main menu), or you can call your nearest branch office.

Individuals who received a COVID-19 vaccine that has not been approved in Canada should follow up with their health care provider or the Thunder Bay District Health Unit for next steps regarding immunization. There is some guidance in the tabs below, you can contact the Vaccine Preventable Disease program by calling (807) 625-5900 or toll-free at 1-888-294-6630 (extension 5108 or press 4 on the main menu), or you can call your nearest branch office.