This helpful video answers a number of common questions concerning the COVID-19 vaccine. 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?
Current Vaccines
Currently, three vaccines are approved by Health Canada; Pfizer-BioNTech, Moderna (which use mRNA technology) and AstraZeneca (which uses 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 new 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.
Vaccine Approval
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 is using a fast-tracked scientific review process that allows manufacturers to submit data as it becomes available, and for Health Canada experts to start the review process right away. Vaccines will only be authorized once all necessary evidence is available.
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 is progressing 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.
Vaccine Effectiveness
The Pfizer-BioNTech COVID-19 vaccine was shown to be 95% effective in preventing COVID-19 beginning 1 week after the second dose.
The Moderna COVID-19 vaccine was shown to be 94% effective in preventing COVID-19 beginning 2 weeks after the second dose.
Protection offered by the first dose is lower than what is achieved after the second dose. The vaccines are more effective after two doses.
Right now, the scientific evidence tells us that the approved vaccines will protect against the variant strains. Research is ongoing and updates will be provided as they are available.
The new variants are concerning because they can spread more easily, but evidence shows that the vaccines are able to prevent mild and moderate cases of COVID-19 and are very effective in preventing hospitalizations and death.
Studies are still underway to determine the effectiveness of the vaccine 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 to continue to follow the advice of public health officials. This includes maintaining a physical distance of at least 2 metres from people outside of your household, wearing a mask, practicing proper hand hygiene and limiting non-essential travel. These measures will help keep you, your loved ones and your community safe.
Vaccine Safety
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:
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)
Both Pfizer-BioNTech and Moderna disclosed reports of several individuals who developed Bell’s Palsy during the period of their trials; however, it was concluded that the most likely cause was viral inflammation of a nerve and not the COVID-19 vaccine. There is also no evidence to link the vaccines to infertility.
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. You can also contact your local public health unit to ask questions or to report an adverse reaction.
Allergic reactions to the vaccine components are possible. The components of each vaccine are available:
Getting Vaccinated
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. This is called “herd immunity” or “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.
The COVID-19 vaccines are not suggested for individuals who:
- are very ill (as a precautionary measure); or
- have received another vaccine (not a COVID-19 vaccine) in the past 14 days.
Vaccination should also be delayed in those with symptoms of COVID-19 and those with confirmed or suspected COVID-19 infection.
So far, a vaccine has not been approved for children. Research is underway to determine when those under the authorized ages can receive the vaccine.
The authorized ages are 16 years of age and older for the Pfizer-BioNTech COVID-19 vaccine and 18 years of age and older for the Moderna and AstraZeneca COVID-19 vaccines.
Certain populations were not included in the clinical trials for the currently approved COVID-19 vaccines, or had very small representation, and require special consideration for 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 with allergies/anaphylaxis to a previous dose or any vaccine ingredients.
- Individuals between the ages of 12 and 15.
There are some people in these groups who may be able to receive the vaccine if a healthcare provider determines that the benefits of vaccine outweigh the risks for the individual and the person consents understanding that there is a lack of evidence on the effects of the vaccine in these groups. See more in the tabs below.
Those who are pregnant, or trying to get pregnant, may be able to get the COVID-19 vaccine depending on individual circumstances.
People who were pregnant were excluded from the Phase III clinical trials for the Pfizer-BioNTech and Moderna COVID-19 vaccines. Therefore, there is limited data on the safety of the vaccines during pregnancy.
Pregnant individuals in the authorized age group may choose to receive the vaccine after counselling and informed consent that includes:
- a review of the risks and benefits of the vaccine
- a review of the potential risks/consequences of a COVID-19 infection in pregnancy
- a review of the risk of acquiring a COVID-19 infection in pregnancy
- an acknowledgment of the insufficiency of evidence for the use of current COVID-19 vaccines in the pregnant population
If after this counselling by their treating provider the pregnant individual feels the potential benefits of vaccination outweigh the potential harms, they should be able to access the vaccine.
Individuals planning on becoming pregnant should speak with their primary care provider. For additional information, consult the Society of Obstetricians and Gynaecologists of Canada Statement on COVID-19 Vaccination in Pregnancy.
Breastfeeding individuals may be able to get the COVID-19 vaccine.
Breastfeeding individuals were excluded from the Phase III trials for the Pfizer-BioNTech and Moderna COVID-19 vaccines. Therefore, there is no data on the safety of the vaccines in lactating individuals, or the effects of mRNA vaccines on the breastfed infant or on milk production.
For any individuals who are breastfeeding, the COVID-19 vaccine should be offered after counselling and informed consent that includes recognizing the insufficiency of evidence for the use of COVID-19 vaccine in the breastfeeding population.