COVID-19 Vaccine Frequently Asked Questions
Below you will find answers to frequently asked questions about COVID-19 vaccines. This list will be updated as information becomes available. Answers to vaccine questions in 27 languages.
To ask a health care provider (doctor or nurse) additional questions about COVID-19 vaccines:
- Book an appointment with SHN to speak with a doctor online or by phone 416-438-2911 ext. 5738
- Book an appointment with Sick Kids Hospital to speak with a pediatric nurse about COVID-19 vaccines for youth or by phone 437-881-3505
About the vaccines
How do COVID-19 mRNA vaccines work?
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.
- Your immune system responds to spike proteins by making antibodies that bind to and block the spike protein on the virus’s surface. This is important for protection from disease because the spike protein is what attaches to human cells, allowing the virus to enter. Blocking this entrance prevents infection.
- Your new antibodies will attack the spike proteins
- Your new antibodies and immune cells will protect you from illness if you are exposed to COVID-19 virus in the future by remembering how to attack the spike protein
Will the vaccines interact with your DNA in any way?
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).
Can I get other vaccines at the same time or after my COVID-19 vaccine?
The National Advisory Committee on Immunization (NACI) has concluded that those age 12+ can get other vaccines at the same time as the COIVD-19 vaccine. You do not need to wait a certain number of days before or after receiving the COVID-19 vaccine to get another vaccine.
For individuals ages 5 to 11 years old:
- COVID-19 vaccines for children 5 to 11 years old should not routinely be given on the same day as other vaccines. At this time, the National Advisory Committee on Immunization (NACI) recommends that children receive the Pfizer-BioNTech COVID-19 vaccine (10 mcg) at least 14 days before or after another vaccine if possible.
- This is a precaution to help to determine if a side effect that may arise is due to the COVID-19 vaccine or another vaccine, rather than a safety concern.
- Parents/guardians should consider these recommendations when choosing an appointment date for children’s vaccinations.
- The minimum waiting period between vaccines is precautionary and there may be circumstances when a dose of a COVID-19 vaccine and another vaccine need to be given at the same time or less than 14 days apart. A healthcare provider can help with this decision
Watch video about getting COVID-19 vaccine at the same time as other vaccines (Black Physicians' Association of Ontario, October 2021)
Will I have to get more than one dose of the COVID-19 vaccine?
Yes. 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. In clinical trials the vaccine showed robust antibody response in youth ages 12 to 17.
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.
A completed two dose COVID-19 vaccine series provides strong protection against COVID-19 and severe outcomes in the general population.
Booster doses (a third dose) are currently available to eligible populations.
If I get the vaccine, how long will it protect me?
At this time, the duration of protection from the vaccines remains unknown and information will continue to be provided as it is available. A completed two dose COVID-19 vaccine series provides strong protection against COVID-19 and severe outcomes, in the general population. However, two doses may not provide sufficient protection based on suboptimal or waning immune response to vaccines and increased risk of COVID-19 infection. 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.
Can I get COVID-19 after being vaccinated?
COVID-19 vaccines are very effective at reducing the risk of severe illness, hospitalization and death and limiting the spread of the virus in a community, but vaccines do not remove all risk of acquiring a COVID-19 infection. Some COVID-19 infections may occur among fully-vaccinated individuals, referred to as ‘breakthrough infection’.
Vaccines work by teaching our immune systems to fight off the virus so that we don’t become severely ill when we come into contact with it, but they cannot prevent us from coming into contact with the virus altogether. The protection a vaccine offers you also depends on the percentage of people around you who are also fully vaccinated (community immunity), other public health measures you follow, and how much of the virus is circulating. That is why everyone should continue to follow public health guidance and advice to protect community members from the transmission of COVID-19. The occurrence of breakthrough infections happens with all vaccines, not just with COVID-19 vaccines.
Your risk of getting COVID-19 and becoming seriously ill or dying is significantly higher if you are not vaccinated, than if you are fully vaccinated. We also know that two doses of a COVID-19 vaccine are more effective against the Delta variant.
Remember that it typically takes two weeks after vaccination for the body to build protection (immunity) against the virus that causes COVID-19 and to reach a level to protect us from severe illness. That means it is possible a person could still get COVID-19 before or just after getting a vaccine. For these reasons, it is important to continue following public health measures even after being vaccinated. This includes staying home if you have any symptoms of COVID-19, wearing a mask, keeping a distance of 2 metres from others, and washing your hands often.
Will I still have to follow other COVID-19 measures once I get the vaccine?
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. This includes staying home if you have any symptoms of COVID-19, wearing a mask, keeping a distance of at least 2 metres from others and washing your hands often.
Will these COVID-19 vaccines work on new strains of the disease?
Data about the efficacy of authorized vaccines against variants is evolving. The National Advisory Committee on Immunization in Canada will continue to monitor the evidence and update recommendations as needed.
If I received the COVID-19 vaccine and need a COVID-19 test a few days later, will I test positive for COVID-19?
Getting a COVID-19 vaccine will not give you a positive result on a COVID-19 test that is needed for travel. It is possible to test positive on an antibody test. However, these are blood tests and are not commonly used in Ontario.
Can I mix vaccine brands for my first, second and booster dose?
The National Advisory Committee on Immunization (NACI) has confirmed that a mixed vaccine schedule (receiving both Moderna and Pfizer) can be completed safely and is effective. All vaccines provide strong protection against COVID-19 and its variants.
For 18 to 29 year olds, it is recommended to receive Pfizer as a booster dose if eligible. However, you may still choose Moderna with informed consent.
The federal government is working with the World Health Organization and the international community to make sure that individuals who are fully vaccinated in ways that Canadians recognize as safe and effective (mixing of vaccines) are also recognized around the world.
Making a decision about getting vaccinated
I’ve already had COVID-19/have COVID-19 antibodies. Do I need the vaccine?
Yes. You should still get vaccinated. At this time, we do not know the length of immune response in those who’ve had a COVID-19 infection. When you get the COVID-19 vaccine, it can help protect you against re-infection and may prevent you from transmitting the virus to others.
If I have been infected with COVID-19, how long should I wait before getting a COVID-19 vaccine?
If you have been infected with COVID-19, you are able to get a COVID-19 vaccine. You should wait to get the vaccine until after the infection (symptoms) is resolved and you are told by Public Health that you no longer need to self-isolate. It is important to wait the full isolation period so that you do not expose other people to the virus.
If you had COVID-19 you should get the vaccine once you have recovered. This is because you may not be immune to the virus that causes COVID-19 and you could get infected again.
If there are effective treatments for COVID-19, why do we need a vaccine?
It is always better to prevent an illness, rather than get it and treat it. A vaccine can help stop you from 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.
Some people have physical and mental health symptoms for weeks or months after having COVID-19. This is sometimes called Long COVID or post COVID-19 condition. It describes a range of symptoms that can last for months after a COVID-19 infection. The most commonly reported symptoms are fatigue, shortness of breath, pain, sleep disturbances, anxiety, and depression. Those who had severe, mild or no symptoms when infected with COVID-19 can get Long COVID.
Although the majority of people who get COVID-19 fully recover, some may not return to their pre-illness levels of health even weeks to months after infection. We do not know why some people have symptoms for weeks or months and others do not. More research is needed.
People with Long COVID-19 may have difficulty with functioning the same as they did prior to getting COVID-19, including difficulty performing daily activities such as getting dressed, decreased ability to care for others (such as children), difficulty returning to work and increased health care use. Estimates suggest that 57,000 to 78,000 Ontarians had or are currently experiencing Long COVID.
Vaccination against COVID-19 reduces the likelihood of long COVID by reducing the chance of becoming infected. In addition, vaccination may reduce the likelihood of developing Long COVID among those with post vaccine (“breakthrough”) infections.
(Source: Ontario COVID-19 Science Advisory Table, 2021)
How do I decide if this is right for me and my family?
Get informed and make your decisions based on evidence and what makes sense for your family. The Pfizer-BioNtech and the Moderna COVID-19 vaccine are currently approved for people over 12 years of age. However, the Ontario government recommends the use of Pfizer-BioNTech vaccine for individuals aged 18 to 29 years old based on the current available analysis from Ontario’s adverse events following immunization (AEFI) surveillance system. Should individuals aged 18 to 29 years old wish to receive Moderna they can continue to do so with informed consent. The Province will continue using the Pfizer vaccine for youth ages 5 to 17.
Vaccination is a personal choice that is 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.
How can I talk to people about getting vaccinated?
Here are some tips for talking to others about vaccines:
- Be positive and non-judgmental
- Encourage people to ask questions about vaccines
- Reassure people that it’s normal to have questions or concerns about vaccines
- Be compassionate and empathetic whenever people share their stories, questions and concerns. Show them you understand their feelings about vaccines
- Encourage people to use credible sources of information (e.g. health care provider, government website)
How many people have been vaccinated in Hamilton?
Check the vaccine distribution page to find out how many people have been vaccinated in Hamilton
Will the COVID-19 vaccines be mandatory in the future?
Some workplaces may require you to get the vaccine as part of their health and safety requirements, just like other vaccines.
Proof of vaccination is required in Canada for domestic and international travel.
Getting a vaccine
Safety and effectiveness of the COVID-19 vaccine
To date, there are 4 COVID-19 vaccines approved for use in Canada by Health Canada.
- Pfizer-BioNTech - approved December 9, 2020
- Moderna – approved December 23, 2020
- AstraZeneca – approved February 26, 2021
- Janssen/Johnson & Johnson – approved March 5, 2021
Vaccine development and approval
Development and approval of the vaccine feels rushed. Can we trust that the COVID vaccine is safe?
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 for all age groups it is approved for. What made this vaccine approval feel faster in comparison to other vaccines is the result of a shared effort by researchers and scientists in every part of the world who 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.
Health Canada granted full approval (Notice of Compliance or NOC) for COMIRNATY® (Pfizer-BioNtech ) to prevent COVID-19 in individuals 12 years of age and older in September 2021.
Who participated in the clinical trials?
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 Pfizer and Moderna vaccine clinical trials.
Source: Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. Polack et al. The New England Journal of Medicine
Several hundred people in the trials self-identified as American Indians or Alaska Natives, but this number was too small to be certain how effective the vaccine was in preventing COVID infections in Indigenous people.
23,848 people participated in the clinical trials for AstraZeneca. Approximately 10% of participants in the clinical trials for AstraZeneca identified as Black.
43, 783 people from across the United States, Latin America, and South Africa participated in the clinical trials for the Janssen/J&J vaccine. Clinical trials for the Janssen/J&J vaccine included participants from across multiple age ranges and racial groups. Clinical trials for the Janssen/J&J vaccine included the following breakdown of participants: 45.3% Hispanic or Latino, 19.4% Black or African American, 9.5% American Indian or Alaska Native, and 3.3% Asian. 33.5% were aged 60 years and older
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.
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.
How effective are the vaccines again severe disease and hospitalization?
All of the approved vaccines have a high efficacy rate against severe disease. In the clinical trials, efficacy against severe disease was shown to be:
- Pfizer: 75-100% (after dose 2)
- Moderna: 100% (14 days after dose 2)
- AstraZeneca: 100% (after dose 2)
Clinical trials showed that beginning 1 week after the second dose, the efficacy of the Pfizer-BioNTech Comirnaty®COVID vaccine against symptomatic COVID-19 was about:
- 95% effective in protecting trial participants from COVID-19 for those 16 years and older
- 100% effective for those 12 to 15 years old
- 90.7% effective for those 5 to 11 years old
Vaccine efficacy is the percentage reduction in disease incidence in a vaccinated group compared to an unvaccinated group under ideal (i.e., clinical trial) conditions (source: WHO). A vaccine with an efficacy of 90% in a trial, for instance, means there was a 90% reduction in cases of disease in the vaccinated group compared to the unvaccinated (or placebo) group.
Real-world studies in adults indicate that mRNA COVID-19 vaccines provide excellent protection against severe disease, including COVID-19 related hospitalization and death following response to the second dose.
Evidence from clinical trials suggests that booster doses of mRNA vaccines given six months after second doses resulted in a good immune response. Real world data suggests that a booster dose provides good short-term effectiveness and safety similar to the second dose of the vaccine. It is unknown at this time how long effectiveness will last.
What is in the COVID-19 vaccine?
COVID-19 vaccines do not contain eggs, gelatin (pork), gluten, latex, preservatives, antibiotics or aluminum.
The ingredients in the Pfizer BioNtech COVID-19 vaccine authorized for use in Canada are:
- Medicinal ingredient
- Non-medicinal ingredients
- ALC-0315 = ((4-hydroxybutyl)azanediyl)bis(hexane-6,1-diyl)bis(2-hexyldecanoate)
- ALC-0159 = 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide
- dibasic sodium phosphate dihydrate
- monobasic potassium phosphate
- potassium chloride
- sodium chloride
- water for injection
- Non-medicinal ingredients (age 5-11)
- ALC-0315 = ((4-hydroxybutyl) azanediyl)bis (hexane-6,1-diyl)bis(2-hexyldecanoate)
- ALC-0159 = 2-[(polyethylene glycol)-2000]-N,N-ditetradecylacetamide
- sodium chloride
- tromethamine hydrochloride
- water for injection
The ingredients in the Moderna COVID-19 vaccine authorized for use in Canada are:
- Medicinal ingredient
- Non-medicinal ingredients
- 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)
- acetic acid
- lipid SM-102
- polyethylene glycol (PEG) 2000 DMG
- sodium acetate
- tromethamine hydrochloride
- water for injection
Note: Polyethylene glycol (PEG) is in both mRNA 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.
Do COVID-19 vaccines contain animal by-products
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.
Does the vaccine contain a microchip and have the ability to track or gather personal information into a database?
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 with in 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.
Vaccine side effects
What are the potential side effects of the vaccine?
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:
|very common ≥10%
(more than 1 in 10 doses)
(1 in 100 to 1 in 10 doses)
(1 in 100 doses)
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 your health care provider (doctor, nurse or 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.
Clinical trial data for vaccine side effects in 5 to 11-year olds was similar to those observed in people age 12+. Children less than 12 had less severe fever and chills after vaccination compared to individuals over age 12 (Source: FDA, 2021). No cases of myocarditis/pericarditis, Bell’s palsy/facial paralysis or MIS-C were reported in the study (Source: FDA, 2021).
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.
Could the vaccine side effects be worse than getting COVID-19?
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 (called ‘Long COVID’).
Your risk of dying from COVID-19 increases as you age, if you are male or if you have chronic health conditions such as heart or lung disease or diabetes.
Is there long-term evidence on potential harms?
As part of the vaccine safety program in Canada, ongoing, careful monitoring of the COVID-19 vaccines will continue. Very careful 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 posts weekly reports on vaccine safety.
Do mRNA vaccine cause pericarditis and/or myocarditis?
Rare cases of myocarditis and pericarditis have been reported after mRNA COVID-19 vaccination (Pfizer-BioNTech and Moderna) in Canada and internationally, including in the United States and Israel. Myocarditis is inflammation of the heart muscle, and pericarditis is inflammation of the lining outside the heart. In both cases, the body’s immune system is causing inflammation in response to an infection or some other trigger. Symptoms can include chest pain, shortness of breath, or palpitations. Available information indicates that these cases have occurred: mainly in adolescents and young adults, more often in males than females, more commonly after the second dose, and typically within several days after vaccination. Most cases appear to be mild and respond well to conservative treatment (e.g. non-steroidal anti-inflammatory drugs) and rest.
The Ontario government recommends the use of Pfizer-BioNTech vaccine for individuals aged 18 to 29 years old based on the current available analysis from Ontario’s adverse events following immunization (AEFI) surveillance system due to an observed increase in Ontario of the very rare heart condition called pericarditis/myocarditis following vaccination with Moderna compared to Pfizer in the 18 to 29 year old age group, particularly among males. The majority of reported cases of myocarditis/pericarditis 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. However, should individuals aged 18 to 29 years old wish to receive Moderna they can continue to do so with informed consent. The province will continue using the Pfizer vaccine for youth ages 5 to17.
No cases of myocarditis/pericarditis were reported in Pfizer clinical trials for those age 5 to 11 (Source: FDA, 2021).
As a precaution, children who experience myocarditis and/or pericarditis after a first dose of the vaccine should wait to get a second dose until more information is available. Children who have a history of myocarditis unrelated to COVID-19 vaccination should consult their clinical care team for individual considerations and recommendations. If they are no longer under active care for myocarditis, they may receive the vaccine.
The rate of myocarditis and pericarditis following a booster dose of a COVID-19 mRNA vaccine is currently unknown.
The benefits of COVID-19 vaccines continue to outweigh their potential risks, as scientific evidence shows that they reduce deaths and hospitalizations due to COVID-19. The Government of Canada encourages people to get vaccinated and to complete their vaccine series as soon as they are eligible.
Do vaccines cause Bell’s Palsy?
The product information for the Pfizer-BioNTech COVID-19 vaccine to describe very rare reports of Bell’s Palsy following vaccination. Cases have been reported in a small number of people in Canada and internationally.
The Moderna COVID-19 vaccine label contains safety information about reported cases of Bell’s Palsy following vaccination.
Health Canada is continuing to monitor side effects for all authorized COVID-19 vaccines in Canada.
Bell's Palsy is typically a temporary facial muscle weakness or paralysis. Symptoms appear suddenly and generally start to improve after a few weeks. The exact cause of Bell’s Palsy is unknown but it is believed to be the result of swelling and inflammation of the nerve that controls muscles on one side of your face.
The benefits of COVID-19 vaccines continue to outweigh their potential risks, as scientific evidence shows that they reduce deaths and hospitalizations due to COVID-19.
Can I get the COVID-19 virus from the vaccine?
The vaccines will not give you a COVID-19 infection. None of the approved vaccines contains a live version of the COVID-19 virus. Instead all the vaccines either deliver, or cause our bodies to make, harmless spike proteins only found on the surface of 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.
How do I report an adverse reaction to the vaccine?
Severe reactions are uncommon but if you need immediate medical assistance, call 911.
Discuss any of the uncommon reactions with your family doctor. If you don’t have a family doctor, a walk-in clinic might be preferred. A doctor can diagnose these uncommon reactions and report them to public health. If you do not have access to a doctor, please call Hamilton Public Health Services Vaccine program at 905-546-2424 ext. 7556 to report symptoms.
Considerations for those with health conditions
I have a health condition. How can I be sure the vaccine is safe?
Some individuals may consider themselves more vulnerable to side effects or negative effects from the vaccine. Speak with your doctor or health care provider about any questions or concerns you have about COVID-19 vaccines.
Can people who have autoimmune disorders or are immunocompromised get the vaccines?
All Health Canada authorized COVID-19 vaccines do not contain live virus and are considered safe in these groups, however there is limited data on long-term efficacy.
These recommendations come from the Ontario Ministry of Health: COVID-19 Vaccination Recommendations for Special Populations:
Individuals with autoimmune conditions, immunodeficiency conditions or those immunosuppressed due to disease or treatment that are receiving stem cell therapy, CAR-T therapy, chemotherapy, immune checkpoint inhibitors, monoclonal antibodies (e.g., rituximab) and other targeted agents (e.g., CD4/6 inhibitors, PARP inhibitors etc.) should be offered the vaccine. These individuals are strongly encouraged to speak with their treating health care provider regarding the timing of vaccination in relation to therapy for their underlying health condition and/or treatment modification plans.
All other individuals with autoimmune conditions, immunodeficiency conditions or those immunosuppressed due to disease or treatment may choose to receive the vaccine. These individuals may choose to consult with their health care provider prior to vaccination (for example, to discuss immunosuppressive medication management/timing in relation to their vaccination).
- 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.
- For additional information on immunodeficiency conditions consult the Canadian Society of Allergy and Clinical Immunology.
- For frequently asked questions about COVID-19 vaccine and adult cancer patients, consult Cancer Care Ontario.
Can people who have allergies get the vaccines?
This information is from the Ontario Ministry of Health: COVID-19 Vaccination Recommendations for Special Populations:
|Individuals who have had an immediate (< 4 hours), severe allergic reaction or anaphylaxis to a previous dose of a COVID-19 vaccine or to any of its components. The allergens included in the vaccine include polyethylene glycol (PEG), tromethamine (trometamol or Tris) and polysorbate 80.||
Should seek evaluation by an appropriate doctor or Nurse Practitioner (NP) as vaccination with an mRNA vaccine can be safely performed in these individuals. This assessment is required to assess the method for possible (re)administration of a COVID-19 vaccine.
Individuals may receive future doses of the same or another mRNA COVID-19 vaccine after consulting with an appropriate doctor. See NACI’s recommendations on the use of COVID-19 vaccines for more information.
Documentation of the discussion with the physician/NP must be provided to the clinic and include a vaccination care plan (including what types of parameters the clinic should meet to provide safe vaccination administration, such as availability of advanced medical care to manage anaphylaxis), details/severity of the previous allergic episode(s), confirm that appropriate counselling on the safe administration of vaccine was provided, and include the date, the clinician’s name, signature and contact information as well as the individual’s name and date of birth.
Individuals who have known or suspected allergies to components of the mRNA vaccines
Should speak with an appropriate doctor or Nurse Practitioner for evaluation. assessment will enable the development of a vaccination care plan which may include receiving the vaccine under the supervision of your doctor.
|Individuals who have had an allergic reaction within 4 hours and/or anaphylaxis that occurred with a vaccine or injectable medication that does not contain a component or cross-reacting component of the COVID-19 vaccines||Can receive the COVID-19 vaccine followed by observation for a minimum of 30 minutes|
|Individuals with a history of significant allergic reactions and/or anaphylaxis to any food, drug, venom, latex or other allergens not related to the COVID-19 vaccine||Can receive the COVID-19 vaccine followed by observation for a minimum of 15 minutes|
|Individuals with allergy issues like allergic rhinitis, asthma and eczema||Can receive the COVID-19 vaccine followed by observation for a minimum of 15 minutes|
Have COVID-19 vaccines been linked to infertility or miscarriage?
COVID-19 vaccines do not cause male or female infertility. There is no scientific reason that the COVID-19 vaccines would impact fertility for those people trying to get pregnant. No loss of fertility has been reported among trial participants or among the millions who have received the vaccines to date, and no signs of infertility appeared in animal studies. Recent research showed that there were no differences in the numbers of conceptions in the vaccine trials between participants who got the vaccine and those who got the placebo. 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 are considering or undergoing IVF or fertility treatments, speak with your health care provider about vaccination. (Source: https://sunnybrook.ca/content/?page=pregnancy-breastfeeding-fertility-covid-19-vaccine).
- American College of Obstetricians and Gynecologists (ACOG), the American Society for Reproductive Medicine (ASRM), and the Society for Maternal-Fetal Medicine (SMFM)
- Society of Obstetricians and Gynecologists of Canada: https://www.sogc.org/common/Uploaded%20files/Latest%20News/SOGC_Statement_COVID-19_Vaccination_in_Pregnancy.pdf
Can people who are pregnant or breastfeeding get vaccinated?
It is recommended that pregnant individuals be vaccinated as soon as possible, at any stage in pregnancy, as COVID-19 infection during pregnancy can be severe.
- COVID-19 infection in pregnancy increases the risk of medical complications and death.
- Pregnant women who contract COVID-19 are:
- Five times more likely to be hospitalized and spend 3.73 days longer in hospital
- 10 times more likely to be admitted to the intensive care unit (ICU)
- More likely to suffer from severe illness
- More likely to require ventilation/life support breathing
(Source: Munshi L, Wright JK, Zipursky J, et al. The incidence, severity, and management of COVID-19 in critically ill pregnant individuals. Science Briefs of the Ontario COVID-19 Science Advisory Table.)
- After the COVID-19 infection has resolved, many pregnant women will continue to experience ongoing medical complications.
- COVID-19 infection in pregnancy significantly increases the risk of stillbirth, premature birth, high blood pressure, caesarean delivery and low birth weight.
- There is also an increased risk that the baby will need to be admitted to neonatal intensive care.
- There is no evidence to suggest that taking the COVID-19 vaccine will impact your pregnancy.
- Several studies with more than 17,000 pregnant women have shown that vaccination immediately prior to and/or during pregnancy has no impact on pregnancy outcomes (i.e. no change in the rate of miscarriage, premature birth, stillbirth, growth restriction, high blood pressure during pregnancy, medical complications of pregnancy or maternal death).
- A study of more than 35,000 pregnant and/or breastfeeding women who were monitored at the time of COVID-19 vaccination found no difference in the rate of side effects compared with non-pregnant individuals.
- Real-world safety data is now available for hundreds of thousands of pregnancy individuals who have received the COVID-19 vaccine.
- The antibodies you make to fight COVID-19 following vaccination also pass to your baby, which may keep them safe after birth.
- The COVID-19 vaccine does NOT contain any live virus, any mercury, aluminum, formaldehyde or any substances harmful to you and/or baby, any human and/or animal blood or by product(s).
Getting vaccinated before getting pregnant will protect you and your future baby from the increased risks association with COVID-19 infections in pregnancy.
It is recommended, but not required, that pregnant individuals have 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.
For additional information on COVID-19 vaccination in pregnancy:
- Video from Ontario health care providers (English, French, Arabic, Cantonese, Farsi, Mandarin, Spanish, Tamil, Vietnamese, Yoruba)
- Information on the COVID-19 vaccine and pregnancy (Prenatal Screening Ontario)
- Pregnancy & Breastfeeding Fact Sheet
- Society of Obstetricians and Gynecologists of Canada
- COVID-19 Vaccination Decision-Making Tool for People who are Pregnant
- Drs Packer and Costescu (HHS): Getting vaccinated while pregnant
- Questions and Answers on Fertility, Pregnancy and Breastfeeding (City of Hamilton, Fall 2021)
COVID-19 vaccines can be safely given to breastfeeding individuals.
- Vaccines protect you from COVID-19 infection and help prevent you from passing it to your baby or other family members.
- You can continue breastfeeding after getting vaccinated; the vaccine is not detectable in breast milk.
- Antibodies have been shown to pass in the breastmilk after maternal vaccination and may protect your baby against COVID-19.
- Studies show that receiving a COVID-19 vaccine while breastfeeding does not disrupt your breastfeeding and does not have an adverse impact on your baby.
Can I get the COVID-19 vaccine while I am menstruating (having my period)? Will it affect my cycle?
People who menstruate (get a period) do not need to schedule their COVID-19 vaccine around their menstrual cycle. There are no issues with getting the vaccine during your period.
Delaying your vaccine around your cycle may leave you unprotected from COVID-19 for a longer time without providing any known benefit.
Menstruation can be influenced by many things, such as environmental changes, stress, sleep and some medications. When your immune system is working hard because you’re vaccinated or sick, you may experience changes in how the lining (endometrium) of the uterus responds so it is possible to see some changes in menstruation.
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 good news is that 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, people with concerns should speak with their doctor since cycles can be delayed for other reasons as well.
Source: Immunize BC
These questions and answers were developed in collaboration with Hamilton's Vaccine Readiness Network.
Simplifying the science of vaccines
- Ask the experts: COVID-19 vaccine questions
- COVID-19 vaccine: What you need to know (Ottawa Public Health)
- COVID-19: How vaccines are developed (Health Canada)
- Vaccine safety in Canada (Health Canada)
- Vaccine safety (Immunize Canada)
- COVID-19 vaccines (World Health Organization)
- Understanding how vaccines work (Yale School of Medicine)
- Vaccine hesitancy (Immunize Canada)
- COVID-19 vaccine (Dr. Evan Adams)
- Moderna vaccine creation
- COVID-19 vaccines (Public Health Ontario)
- How COVID-19 mRNA vaccines work (Health Canada)
- Answering patient questions about COVID-19 vaccines (Centre for Effective Practice)
Understanding mRNA vaccines
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