COVID-19 Vaccines

Vaccines teach your immune system how to protect you from diseases. It's much safer for your immune system to learn this through vaccination than by catching the diseases and attempting to treat them.

mRNA technology has been studied for more than 10 years, most often in cancer research and treatment as well as in the development of new vaccines against such infections as pandemic influenza and rabies.  Shortly after COVID-19 was identified scientists were able to map the genes that make up the COVID-19 virus. Once the structure of the genes was known, especially of the spike protein that allows that virus to fuse with and enter our cells, scientists were able to quickly create the vaccine and start the clinical trials that have resulted in the Pfizer and Moderna vaccines that have been approved for use by Health Canada.

Below is an explanation of how the approved Pfizer-BioNtech and Moderna mRNA COVID-19 vaccines work with your body’s immune response to fight off the COVID-19 virus.

COVID-19 mRNA vaccines tell your body to make "spike proteins" (these cover the outside of the virus and allow it to attach to and enter our cells) specific to virus that causes COVID-19.

Building up immunity takes time. One dose of vaccine may not be enough to provide individual protection. You may need to get a second shot to allow your body to develop adequate immunity.

For the currently approved Pfizer-BioNtech COVID-19 vaccine, two doses of the vaccine are required for better protection, given 21 days apart. It can be given to people 16 years of age and older, including seniors. After completing the two-doses, it may take another seven days to achieve maximum protection against COVID-19. The Pfizer-BioNtech clinical studies included over 43,000 participants and was 95% effective in preventing COVID-19 beginning 2 weeks after the second dose.

Two doses are also required for the Moderna vaccine. Based on studies in about 30,000 participants, the Moderna COVID-19 vaccine was 94.1% effective in preventing COVID-19 beginning 2 weeks after the second dose. This means that people may not be fully protected against COVID-19 until at least 14 days after the second dose. The Moderna vaccine is approved for people 18 years or older at this time.

Yes. You should still get vaccinated. At this time, we do not know the length of immune response in those who’ve had the COVID-19 infection. . When you have the COVID-19 vaccine, it can help protect you against re-infection and may, we hope, also prevent you from transmitting the virus to others.  

It is always better to prevent an illness, rather than get it and treat it. A vaccine can help stop you getting ill, lessen the impact of COVID-19 and slow it spreading in the community. There is some evidence to show that even a mild case of COVID-19 can be harmful to a person’s respiratory and cardiac system.

At this time, the duration of protection from the vaccines remains unknown, and further doses may be necessary. The duration of immunity from contracting the infection also remains unknown. Ongoing monitoring of the COVID-19 vaccines and their effects on long-term immunity continues.

The vaccines will be provided free to everyone who wants it. It will take some time to get the vaccine to everybody, and vaccines will be distributed to priority groups first (such as acute healthcare workers and residents of long-term care facilities) but, when you are able, you will get it for free.

Yes, it is essential that you still act to prevent the spread of COVID-19 in the community, so it is important to follow  public health measures until we have reached a level of community vaccination that suggests widespread immunity. This includes wearing a mask when indoors, or when you cannot physically distance from others, continuing to avoid crowded spaces and social gatherings, regular handwashing, and staying home when sick.

Get informed and make your decisions based on evidence and what makes sense for your family. Note that the Pfizer-BioNtech COVID-19 vaccine is currently only approved for people over 16 years of age. The Moderna vaccine is approved for people who are 18 years of age and older.

Vaccination is a personal choice that the vast majority of Canadians agree is part of good health and important for prevention of serious disease.

Public Health recommends that everyone who is eligible gets the vaccine once it is available, but recognize that the choice is not always as easy as following this advice. Take the time to read and understand the vaccine information on this page and from other reliable sources. 

Follow-up by asking questions and reaching out to trusted medical experts like your family doctor, nurse practitioner, or health care provider.

mRNA is a short-form of ‘messenger RNA’ – meaning that it’s a messenger.
DNA is contained in the nucleus of our cells and mRNA cannot get into the nucleus or interact with our DNA.

mRNA cannot change your DNA, it is a part of our genetic material that gives instructions to the body, like a recipe. It simply delivers a message.

• For COVID-19, the mRNA vaccine tells the body to make a harmless “spike protein”. This spike protein is found on the outside of the COVID-19 virus (but is not the virus itself). Our immune system recognizes the spike protein as something that shouldn’t be there and quickly works to attack it by building antibodies and immune cells that will attack the COVID virus if you are exposed in the future.

Human cells break down and get rid of the mRNA soon after they have finished using the instructions. mRNA does not interact with the part of our cells that holds our DNA and cannot be ‘swapped out’ or change the DNA sequence (there only function is to deliver the message of the spike protein to the cell).

No, the vaccine does not contain a “microchip”. This concern started after comments made by Bill Gates from The Gates Foundation about a digital certificate of vaccine records. A digital certificate is not something that can be contained within a vaccine and is not a microchip. The technology referred to by Gates has nothing to do with the development, testing or distribution of the COVID-19 vaccine.

The mRNA COVID-19 vaccines have been deemed ‘permissible or recommended’ by the Vegan Society, Muslim and Jewish councils in the USA. There are no pork-derived materials, the fatty layers that protect the mRNA are plant-based or synthetic, there are no blood fractions or fetal cells products in the vaccines.

Source: South Asian COVID Task Force Canada.

COVID-19 vaccines should not be given at the same time as other vaccines:

• If possible, wait for at least 14 days after receiving another vaccine before getting the mRNA COVID-19 vaccine. It is not a safety concern if it has been less than 14 days. Separating vaccines by 14 days can help us determine which vaccine may have caused a side effect if one happens. 
• Wait at least 28 days after finishing the two-dose vaccine series of a mRNA COVID-19 vaccine before getting another vaccine (except in the case where another vaccine is required because you have been exposed to another vaccine-preventable disease).

Please talk to your immunization provider if you have more questions. 

As part of Phase One of Ontario’s three-phased COVID-19 Vaccination Plan, Hamilton will participate in distributing the Pfizer- BioNTech COVID-19 vaccine to priority groups who have been selected to receive the COVID-19 vaccine. Read more about the newly approved Moderna vaccine and its anticipated impact on Ontario’s Vaccination Plan.

Given the limited availability of vaccines at the present time and in order to ensure that those at highest risk from serious illness due to COVID-19 are protected first, the provincial and federal governments have established a priority list of who will get which vaccine and in what order.

In the first few months of Ontario’s vaccine rollout, the vaccine will be available for:

• residents, staff, essential caregivers and other employees who work in congregate living settings providing care for seniors as they are at higher risk of infection and serious illness from COVID-19 (essential caregivers provide care services to one resident at a home but are not staff)
• health care workers (including hospital employees, other staff who work or study in hospitals, and other health care personnel)
• adults in First Nations, Métis and Inuit populations where infection can have disproportionate consequences, including those living in remote or isolated areas where risk of transmission is high
• adult recipients of chronic home health care

As more vaccine becomes available and as Ontario’s plan moves forward, know that you will be offered a vaccine which has been approved by Health Canada as safe and effective and is recommended by the Public Health Agency of Canada for persons of your age or risk group.

See Ontario’s COVID-19 Vaccination plan for more information. 

If you are eligible for the first round of vaccine distribution, correspondence will come from your employer informing you about your vaccine eligibility, where to go and what to do on the day so that you can get vaccinated in a setting with COVID-19 protocols in place.

Vaccines are currently only available to priority groups identified in the provincial plan. If you are eligible for a vaccine, your employer, care facility or Public Health will contact you to book an appointment. Ontario’s vaccination plan is available at: https://covid-19.ontario.ca/covid-19-vaccines-ontario

There is a misconception that vaccine research must take a long time. While creating a new vaccine can sometimes take years, the progress on COVID-19 vaccines is happening quickly for many reasons, including:

• advances in science and technology
• international collaboration among scientists, health professionals, researchers, industry and governments
• increased dedicated funding

For any vaccine to reach the general public it must pass careful evaluation by Health Canada and will have to pass safety standards. What made this vaccine approval feel rushed in comparison to other vaccines is the result of a highly focused and shared effort by researchers and scientists in every part of the world - combined new processes for review and evaluation of clinical trial data in addition to increased funding for vaccine research.

No corners were cut while creating the vaccines. One minor change to the usual process was put in place: clinical trials were run at the same time as the vaccines were being made/manufactured; that way, vaccines could be shipped out to different countries as soon as the vaccines were approved by the different countries’ health authorities.

The different clinical trials included over 70,000 people. 43,448 people were included in the Pfizer trials; 30,000 people were included in the Moderna vaccine trials.

Between 35-40% of the participants were Black or African American, Latinx and Hispanic in both vaccine clinical trials (Pfizer BioNtech and Moderna).
Source: Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. Polack et al. The New England Journal of Medicine

Clinical trials make efforts to include a wide range of people to make sure that the evidence would support a wide range of people benefitting from vaccination. There are some groups that were not included in the clinical trials, including people who are pregnant or breastfeeding, people under the age of 16, or people who have weaker immune systems. Often vaccine clinical trials start with healthier people and, if successful, go on to other at-risk populations, for example, people with chronic illnesses. This can take additional time to decide if a vaccine is effective but is very important as these people are at greater risk of adverse COVID-19 impacts.

Clinical trials in children older than 12 years old have begun. Canadian guidelines for COVID-19 vaccines in people who are pregnant, breastfeeding or are immunocompromised can be found here.

The vaccine trials included people over the age of 65 and the vaccine was found to be safe and effective in this age group.
Source: https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-conclude-phase-3-study-covid-19-vaccine

For the currently approved Pfizer-BioNtech COVID-19 vaccine two doses of the vaccine are required for better protection, given 21 days apart. It can be given to people 16 years of age and older, including seniors. After completing the two-doses, it may take another seven days to achieve maximum protection against COVID-19.

Two doses are also required for the Moderna vaccine. Based on studies in about 30,000 participants, the Moderna COVID-19 vaccine was 94.1% effective in preventing COVID-19 beginning 2 weeks after the second dose. This means that people may not be fully protected against COVID-19 until at least 14 days after the second dose. The Moderna vaccine is approved for people 18 years or older at this time.

Some individuals may consider themselves more vulnerable to side effects or negative effects from the vaccine. 

When it is confirmed which vaccines will be used, we will be open and transparent about characteristics of each vaccine and details of which vaccines will be most suitable for each group. 

Doctors, nurses and vaccinators will be fully informed of vaccine characteristics, effectiveness and risks. Individuals are advised to discuss any concerns when they are invited to be vaccinated.

Information will be provided to people before vaccination (and will be available online) to reassure about safety and allow informed decisions. 

See below for the full list of ingredients in the Pfizer-BioNtech and Moderna COVID-19 vaccines.

The Pfizer/BioNTech vaccine and Moderna vaccine do not contain egg.

Health Canada has full lists of ingredients for both vaccines.

Pfizer/BioNTech and Moderna have reported that their vaccines contain no preservatives.

Different vaccines have different storage needs. For example, the Pfizer/BioNTech vaccine must be stored at minus 70 degrees Celsius, and the Moderna vaccine needs to be stored at minus 20 degrees Celsius. Both of these vaccines use messenger RNA, or mRNA, to teach your cells how to make a protein that will cause an immune response to COVID-19. However, messenger RNA is fragile and can break down easily. Storing messenger RNA vaccines in an ultracold environment keeps them stable and safe. You should not worry about these temperatures. Vaccines are thawed before injection.

After being vaccinated, it's common to have mild side effects. This is the body's natural response, as it's working hard to build immunity against the disease. This is known as the inflammatory response or reaction. Side effects will likely be moderate and resolve after a few days.

Common side effects that have been reported in the clinical trials for the Pfizer BioNtech COVID-19 vaccine include:

These effects are more likely after the second dose of vaccine and will typically go away in a day or two. These effects are a normal part of your body’s response to most vaccines – it is a sign that your body’s immune system is learning how to recognize and fight the virus that causes COVID-19. Some people may experience more serious allergic reactions to the vaccine, but these are unlikely and tracked closely by Health Canada as part of on-going monitoring of vaccine safety.

If you have questions about these effects, reach out to a trusted health care provider, like your family doctor, nurse or local pharmacist.

In rare cases, serious allergic reactions (anaphylaxis) can occur. Allergic reactions can be treated and are usually temporary. Seek medical attention if you have trouble breathing, have hives or swelling of the face and throat. Vaccine side effects will continue to be monitored as people receive the vaccine. If you get a reaction to the vaccine, contact your health care provider who will report the side effect directly to public health. Public health will keep track of the reported side effects to make sure the vaccine continues to be safe.

Precautions

• Delay getting vaccinated if you have a fever, are sick with COVID-19 symptoms, or have received a vaccine in the past 14 days.
• Avoid trying to get pregnant for at least two months after getting both doses of the vaccine.
• Consult your health care provider if you have a bleeding disorder or are on blood thinner medication.

Visit Health Canada for more information on the side effects of the Pfizer BioNTech COVID-19.

Common side effects that have been reported in the clinical trials for the Moderna COVID-19 vaccine include mild to moderate: pain at the site of injection, body chills, feeling tired and feeling feverish.

Visit Health Canada for more information on the potential side effects of the Moderna COVID-19 vaccine.

Some people’s experience of COVID-19 may be mild, but it can also cause some people to become very sick or even lead to death. There is some research to show that even a mild case of COVID-19 can be harmful to a person’s lungs (which makes breathing hard) and to their heart and cardiovascular system (your heart and how blood flows through your body). There is also a worrisome number of people experiencing on-going and at times debilitating symptoms for weeks or months after their initial COVID-19 infection (sometimes called ‘long COVID’).

On social media, some people are saying that only 1%-2% of people with COVID-19 die from it and that people should not be vaccinated because the chance of dying is low. However, even if only 1% of people with COVID-19 die, that is 10 times more than the seasonal flu. Your risk of dying from COVID-19 also increases as you age, is you are male or if you have chronic health conditions such as heart or lung disease or diabetes.

No vaccine is 100% effective, but they are far better than not getting a vaccine. The benefits are greater than the risks.

As part of the vaccine safety program in Canada, ongoing, careful monitoring of the COVID-19 vaccines will continue. Very careful and continuous post-marketing tracking of those vaccinated will be carried out by the healthcare and public health systems at local, provincial and national levels. There is also longer-term follow-up of those who were vaccinated as part of the clinical trials. Health Canada has committed to being transparent with this monitoring of vaccine safety.

There is no science-based reason why a COVID-19 vaccine would lead to infertility or miscarriage.

The best evidence comes from women who got sick with COVID-19 while pregnant. Studies show that pregnant women are more likely to be hospitalized when they have COVID-19, but they are not more likely to miscarry.

If you were to get COVID-19, your body creates the same immune response as it does when you receive the vaccine. If this immune response caused miscarriages, we would have already seen more miscarriages in women naturally infected with COVID-19. This has not happened.

There is limited information on the use of COVID-19 vaccines in pregnant people and people who are breastfeeding.

• Pregnancy
  The current recommendation is that people who are pregnant in the authorized age group (16+ for Pfizer BioNTech vaccine; 18+ for Moderna vaccine) may choose to receive the COVID-19 mRNA vaccine after speaking with their treating health care provider on the risks and benefits to the individual and consent.
  For additional information on COVID-19 vaccination in pregnancy: Society of obstetricians and gynecologists of Canada Statement on COVID-19 Vaccination in Pregnancy
• Breastfeeding
  There is limited information on the use of COVID-19 vaccines while breastfeeding. mRNA vaccines do not contain live virus. Based on how mRNA vaccines work in the body, scientists do not believe there is a risk to the breastfeeding infant.

  Breastfeeding individuals in the authorized age group (16+ for Pfizer BioNTech vaccine; 18+ for Moderna vaccine) may choose to receive the COVID-19 mRNA vaccine after speaking to a health care provider about the risks, benefits, and lack of specific research data.

There is limited information on the use of COVID-19 vaccines in people who have autoimmune disorders and people who are immunocompromised. It is possible that the vaccine will have decreased effectiveness due to immunosuppression.

Immunosuppressed individuals in the authorized age group (16+ for Pfizer BioNTech vaccine; 18+ for Moderna vaccine) with autoimmune conditions, immunodeficiency conditions, or those immunosuppressed due to disease or treatment may choose to receive the vaccine after speaking to a health care provider about the risks, benefits, and lack of specific research data.

Individuals who are immunosuppressed due to disease or treatment or with an autoimmune condition, should consult their treating provider to discuss getting the COVID-19 vaccines.

• Health Canada recommendations
• For additional information on organ transplantation, consult the Canadian Society of Transplantation statement on COVID-19 vaccination.
• For additional information on rheumatology, consult the Canadian Rheumatology Association statement on COVID-19 vaccination.
• For additional information on inflammatory bowel disease, consult the Canadian Association of Gastroenterology statement on COVID-19 vaccination.

Scenario One
Individuals who have ever had a severe allergic reaction (i.e. anaphylaxis) to a previous dose of an mRNA vaccine or to any of its components (listed below) or its container, should not get either mRNA COVID-19 vaccine.

Scenario Two
Individuals who have a suspected hypersensitivity or have had an immediate allergic reaction to:

• a previous dose of an mRNA COVID-19 vaccine
• any of components of the mRNA COVID-19 vaccine (including polyethylene glycol [PEG])
• polysorbate

should not get mRNA COVID-19 vaccine unless they have been evaluated by an allergist-immunologist and it is determined that the person can safely receive the vaccine.

Scenario Three
Individuals who have had a severe allergic reaction (i.e., anaphylaxis) to other vaccines or injectable therapies, must be evaluated by an allergist-immunologist before getting the COVID-19 vaccines so that a thorough risk/benefit discussion can take place and vaccination safety plan developed.

Scenario Four
Individuals who have had an immediate allergic reaction to other vaccines or injectable therapies must discuss the risks and benefits of vaccination with their treating health care provider. In some cases, your treating health care provider may consult with an allergist-immunologist.

Scenario Five
Individuals with a history of severe allergic reactions (i.e. anaphylaxis) not related to vaccines or injectable medications (for example, allergies to food, pet, venom, environmental, or latex, etc.) may choose to have the COVID-19 vaccines. The vaccination clinic will monitor you for 30 minutes following vaccination. With an extended period of observation following vaccination (30 minutes).

Ingredients in available COVID-19 vaccines

Pfizer-BioNTech Vaccine Ingredients:

• mRNA (medicinal ingredient)
• ALC-0315 = (4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
• ALC-0159 = 2-[(polyethylene glycol)-2000]-N, N-ditetradecylacetamide
• 1,2-distearoyl-sn-glycero-3-phosphocholine
• dibasic sodium phosphate dehydrate
• monobasic potassium phosphate

Moderna Vaccine Ingredients:

• mRNA (medicinal ingredient)
• 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)
• acetic acid, cholesterol, lipid SM-102
• PEG2000DMG1,2-dimyristoyl-rac-glycerol,methoxy-polyethyleneglycol
• tromethamine, tromethamine hydrochloride
• sodium acetate, sucrose, and water for injection

Note: Polyethylene glycol (PEG) is in both vaccines. It can also be found in laxatives, makeup, skin care products, personal lubricants, toothpastes, and some contact lenses. It is also in cough syrup, and in some food and drinks.

If you are unsure of the ingredients you are allergic to, talk to your health care provider.

The vaccine will not make you sick with COVID-19.

The Pfizer and Moderna vaccines rely on mRNA (messenger RNA) - this means that the vaccine does not contain a live version of the COVID-19 virus. Instead it delivers the genetic information (mRNA or a ‘recipe’) about the ‘spike’ protein that surrounds the COVID-19 virus and teaches your body how to spot and respond to this protein so when the real virus comes along, the body can fight it off.

Both Pfizer and Moderna are looking into whether or not the vaccine will work on the new strain of the virus. So far, there is no evidence that shows the vaccine will not work. More research is needed, and Health Canada will watch this closely.