About the vaccine

COVID-19 vaccination is one of the best ways we can protect ourselves from severe outcomes of COVID-19 infection. While many people who get COVID-19 have only mild illness, others may experience severe illness or even die. There is no way to know how COVID-19 will affect you, even if you are not at increased risk of severe complications.

The COVID-19 vaccines are safe, effective and have been shown to:

• Help protect you by creating an antibody response without having to experience the illness of COVID-19, reducing your risk of getting COVID-19.
• Reduce your risk of severe illness or death if you do get COVID-19.
• Reduce your risk of spreading the virus that causes COVID-19 to others.

The more people who are vaccinated in the community, the less the risk of the virus spreading, replicating, mutating, and possibly becoming more resistant to vaccines.

• The reason for a booster dose is to restore protection that may have decreased over time to a level that is no longer effective, in people who initially responded well to a complete vaccine series.
• This is different than a third dose which might be added to the standard “primary vaccine series” with the aim of enhancing the immune response and establishing an adequate level of protection for people who did not develop immunity, or who developed a sub-optimal immune response to a two-dose primary series.
• In short – a primary series for most healthy people remains two doses, and for these people, a third dose (first booster) is offered to boost the immune system. A three-dose primary series is offered to those who are immunocompromised or vulnerable to severe illness to ensure they have an adequate immune response and are protected. A fourth/fifth dose (first/second booster) is then offered to this population to boost their immune response and help increase protection against severe outcomes from the virus.

On September 1, 2022 Health Canada authorized the Moderna COVID-19 bivalent vaccine for use as a booster dose in individuals aged 18 and older. This bivalent vaccine targets both the original COVID-19 virus and the Omicron variant BA.1.

On October 7, 2022 Health Canada authorized the Pfizer-BioNTech COVID-19 bivalent vaccine for use as a booster dose in individuals aged 12 and older. This bivalent vaccine targets both the original COVID-19 virus and the Omicron variants BA.4 and BA.5.

Existing COVID-19 vaccines are monovalent meaning they target only one strain of the virus, i.e. the original virus. The new boosters are a bivalent vaccine meaning it targets two virus strains - the original and the Omicron subvariant BA.1.

• There have been several different variants and subvariants of COVID-19 during the pandemic including Alpha, Delta and most recently Omicron. The Omicron variant has been responsible for nearly all COVID-19 infections in Ontario in 2022.

Clinical trial results show that a booster dose of a bivalent vaccine is safe and effective, and triggers a strong response against both Omicron sub-variants and the original SARS-CoV-2 virus. It is also expected to extend durability of protection. 

At this time, there is no evidence to suggest any meaningful difference in protection between the BA.1 (Moderna) and BA.4/BA.5 (Pfizer) vaccines. Bivalent Omicron-containing COVID-19 vaccines have all been shown to induce stronger and more robust immune responses to the Omicron variant when compared to the original (monovalent)vaccines. [Updated guidance on COVID-19 vaccine booster doses in Canada | NACI, October 7, 2022]

The term multivalent may also be used. This means that a vaccine targets multiple or more than one virus strain. The annual influenza vaccine is an example of a multivalent vaccine. It may target 3 or 4 different strains of the influenza virus.

• Developing immunity from infection, sometimes called “natural immunity,” requires exposure to an unpredictable virus with known serious consequences, including risk of severe illness and death. It is not known how long this immunity lasts. Immunity will wane (decrease) over time and it is possible to be re-infected with COVID-19.
• Vaccines provide a way for your body to develop immunity to COVID-19 without the risk of severe disease from COVID-19 infection.
• Vaccination is recommended for everyone ages 6 months and older, regardless of previous COVID-19 infection, to prevent serious illness and complications from COVID-19. Since protection after a primary series of the COVID-19 vaccine decreases over time, especially against the Omicron variant, it is further recommended that individuals aged 5 and older receive a COVID-19 vaccine booster dose to help restore protection against the virus.
• Some individuals may be eligible for booster doses after completing a primary series.
  • Children aged 5 to 11 years may receive a monovalent booster dose 6 months (168 days) after completing their primary series.
  • For individuals 12 years of age and older who have completed their primary series, a booster dose is recommended 6 months (168 days) after a previous dose or booster.
  • For high-risk individuals, it is strongly recommended that they receive a booster dose 3 months (84 days) from a previous dose or booster. High-risk individuals include:
    • Pregnant individuals 18+
    • Adults 65+
    • Moderately to severely immunocompromised individuals 12+
    • A First Nations, Inuit, and Métis individual or a non-Indigenous household member 18+
    • A resident of a long-term care home, retirement home, or Elder Care Lodge
    • An individual living in other congregate settings that provide assisted living and health services
    • Health care workers 18+ 

• COVID-19 vaccination (including getting any eligible booster doses) is strongly recommended before becoming pregnant or in any trimester of pregnancy. Getting vaccinated, as soon as possible, is the safest choice to protect yourself and your baby from the known risks of COVID-19 infection.
• The National Advisory Committee on Immunization (NACI) recommends you get a complete series with an mRNA COVID-19 vaccine if you're pregnant or breastfeeding. Getting the COVID-19 vaccine can prevent serious illness, hospitalization, and complications from COVID-19 infection.
• The Society of Obstetricians and Gynaecologists of Canada (SOGC) also recommends that all individuals who are pregnant or those trying to become pregnant should receive all COVID-19 vaccination doses, including a booster dose, when eligible. Pregnant individuals who are unvaccinated are at risk for severe COVID-19 complications.
• If you get vaccinated while breastfeeding, the vaccine itself will not transfer into breastmilk, but studies suggest that the antibodies you produce following vaccination will, which may protect your baby from COVID-19.

• COVID-19 Resources | Provincial Council for Maternal and Child Health
• COVID-19 Vaccination in Pregnancy | Society of Obstetricians and Gynaecologists of Canada
• COVID-19 vaccines in pregnancy | Ministry of Health

• chest pain
• shortness of breath
• heart palpitations (fluttering or pounding of the heart)

Although very rare, there have been reports of myocarditis and/or pericarditis after immunization with mRNA COVID-19 vaccines in Canada and internationally for ages 12 and older. For most people, the heart inflammation is mild and goes away within days.

So far, available information indicates that:

• Cases were more commonly reported after the second dose
• Symptom onset was typically within several days after vaccination
• Cases were mainly adolescents and young adults
• Cases were more often in males than in females
• Cases experienced mild illness, responded well to conservative treatment and rest, and their symptoms improved quickly

Out of an abundance of caution and following a comprehensive review, the National Advisory Committee on Immunization (NACI) updated and approved its recommendations on the use of the COVID-19 vaccines authorized for use among individuals aged 12 years and older in the context of myocarditis and pericarditis following vaccination. For individuals aged 12 to 29, the use of the Pfizer-BioNTech COVID-19 vaccine is recommended to start or continue the mRNA primary vaccine series to minimize myocarditis/pericarditis risk. Should individuals aged 18 to 29 wish to receive the Moderna vaccine, they can continue to do so with informed consent.

If you develop any symptoms, chest pain, shortness of breath, or the feeling of a fast-beating, pounding or fluttering heart, get medical attention immediately. Report any adverse events after immunization to your healthcare provider.

It is also important to remember that the COVID-19 virus itself can cause inflammation, which can include myocarditis or pericarditis. The benefits of vaccination outweigh the potential risks.

Video: Dr. Hayward | Myocarditis/Pericarditis after COVID-19 vaccine

Many people are beginning to travel once again. It is important to assess your own personal risk. It is important to assess your own personal risk factors for travel. It is also important to be aware of the COVID-19 situation at your travel destination. Please check with the country you are travelling to for vaccine, testing, isolation and other requirements.

If you do travel outside of Canada, you should plan how you will meet Canada’s travel requirements when you return. For more information, visit COVID-19: Travel, testing and borders.

When travelling within Canada, there may be provincial or territorial requirements. Check provincial and territorial resources for what you need to do if you're symptomatic or have tested positive for COVID-19.

It's still possible to come in contact with the COVID-19 virus and develop symptoms if you are fully vaccinated. To help stop the spread and protect others who may not be vaccinated or who are unable to be vaccinated, it is important that people who develop symptoms (even if fully vaccinated) continue to take precautions like staying home when sick.

If you are sick with COVID-19 or another respiratory illness, stay home to prevent spreading the virus to others, except to seek testing or medical care if required.

You should stay home until all of the following apply to you:

• Your symptoms have been improving for at least 24 hours (or 48 hours if you had nausea, vomiting and/or diarrhea)
• You do not have a fever
• You do not develop any additional symptoms

When your symptoms are improving and you are no longer isolating at home, doing the following can provide extra protection against the spread of COVID-19 and other respiratory viruses circulating in the community. For 10 days after your symptoms started:

• Wear a well-fitted mask in all public settings
• Avoid non-essential activities where you need to take off your mask (for example, dining out)
• Avoid non-essential visits to anyone who is immunocompromised or may be at higher risk of illness (for example, seniors)
• Avoid non-essential visits to highest risk settings in the community such as hospitals and long-term care homes

For more information see the current public health measures and advice.

If you become ill with any symptoms of COVID-19, even after receiving the vaccine, complete the Ontario Ministry of Health COVID-19 self-assessment for recommendations on what to do next. For questions about COVID-19 testing and isolation guidelines, call the Provincial Testing and Isolation Information line at 1-888-777-0730.

Huron Perth Public Health continues to recommend that anyone with symptoms of COVID-19 consult with a health care provider if they have questions or concerns.