No, the Covid-19 and influenza vaccine are separate products. COVID-19 vaccine will not protect you against influenza. The seasonal influenza vaccine changes every flu season. When you receive your annual flu vaccine, you are protected only from the specific influenza strains that are circulating for that given season that are covered by the vaccine.

The Pfizer-BioNTech COVID-19 Vaccine is a vaccine used to prevent COVID-19 disease caused by the SARS-CoV-2 virus.

Herd immunity is a term used to describe when enough people have protection—either from previous infection or vaccination—that it is unlikely a virus or bacteria can spread and cause disease throughout the population. As a result, on average, the whole population within the community is protected even if some people don’t have any protection themselves. However, isolated or short chains of transmission could still occur. The percentage of people who need to have protection in order to achieve herd immunity varies by disease.

Experts do not know what percentage of people would need to get vaccinated to achieve herd immunity to COVID-19. Some estimates for COVID-19 suggest it may be near 60 to 70%, though the full range of estimates is much broader. While experts learn more about the protection that COVID-19 vaccines provide under real-life conditions, it will be important for everyone to continue practicing public health measures to help stop the spread of COVID-19.

(See also: FAQ: Once a person is vaccinated with the series of two doses of the COVID-19 vaccine, can they stop following public health measures like wearing a mask, physical distancing and self-isolating when they become sick?)

Yes. Those who have previously tested positive for COVID-19 should still be vaccinated and people 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.  

At this time, experts do not know how long someone is protected from getting sick again after recovering from COVID-19. The immunity developed after having an infection, called natural immunity, is different from person to person. Some early evidence suggests natural immunity may not last very long. We need more information on how well the vaccine works to be able to assess how long immunity from the vaccine will last.

It usually takes the body a few weeks to build immunity after receiving a vaccine. It is possible that someone could become infected with the COVID-19 virus before or just after getting the vaccine and get sick. This happens because the vaccine has not had enough time to provide protection in the body. Learn more about COVID-19.

Studies of COVID-19 vaccines have shown that they are very effective at preventing people from becoming sick with COVID-19.However, right now we do not have enough information to show us how likely it is that someone who has been given a COVID-19 vaccine can develop an asymptomatic(no symptoms) COVID-19 infection and pass it to others.  

While there is early evidence suggesting that the vaccine may also reduce COVID-19 transmission, NACI is recommending that everyone continue to practice public health measures (e.g. wearing a face mask and physical distancing) regardless of whether or not they received a COVID-19 vaccine. More information on the vaccine’s ability to reduce COVID-19 transmission is expected in the near future.  

This means the vaccines will protect those who receive it from getting sick, but it is possible that someone who has been vaccinated could still carry the virus pass the virus on to others, although it would likely be at a much lower rate.  

No. While experts learn more about the protection that COVID-19 vaccines provide under real-life conditions, it will be important for everyone to continue practicing public health measures to help stop the spread of COVID-19. That means covering your mouth and nose with a mask, washing hands often and never touching your eyes, nose or mouth with unwashed hands, staying at least 2 metres (6 feet) away from others and self-isolating when sick.  

No. People with a history of severe allergic reaction to a component of the COVID-19 vaccine should not receive the vaccine. 

Visit the Health Canada web page to learn who should not received the Pfizer-BioNTech or Moderna vaccines.

The most frequent side effects are injection site pain, fatigue and headache. Some people receiving the vaccine in trials also reported muscle pain, chills, joint pain and fever. These symptoms were usually mild or moderate in intensity and resolved within a few days after vaccination. These are all expected reactions to vaccines because of the immune response and are very similar to those reported following the seasonal influenza vaccination.

Visit the Health Canada webpage for more information on the side effects of the Pfizer-BioNTech or Moderna vaccines.

No serious safety concerns have been causally linked to COVID-19 vaccines approved in Canada.

If someone experiences an adverse event following immunization, they should report it to a healthcare professional (e.g., family doctor).

An adverse event following immunization (AEFI) is an unwanted or unexpected health effect that happens after someone receives a vaccine, which may or may not be caused by the vaccine.

Healthcare professionals should complete the Adverse Events Following Immunization (AEFI) Form and send it to the local public health unit.

Public health surveillance of AEFIs is important for timely detection of rare vaccine safety issues. For more information visit the OPH page on AEFI reporting.

Expected side effects for each vaccine product are listed on the vaccine product monograph; common side effects could be found under ‘Side effects and risks’.

National Advisory Committee on Immunization (NACI) recommends that if a risk assessment with a health care provider deems that the benefits outweigh the potential risks, and if informed consent includes discussion about the absence of evidence on the use of COVID-19 vaccine then a complete series of COVID-19 vaccine may be offered to the following populations: 

• Delay getting vaccinated if you have a fever or are sick with COVID-19 symptoms.  This helps to avoid attributing any complications from other illness with vaccine-related adverse events, and to minimize COVID-19 transmission at an immunization site
• The National Advisory Committee on Immunization (NACI) recommends that individuals delay pregnancy by at least 28 days after the completion of a two-dose series of mRNA COVID-19 vaccines. Up to date recommendation from NACI can be found here.
• The National Advisory Committee on Immunization (NACI) recommendations support that individuals who are on long-term anticoagulation are not at higher risk of bleeding complications after immunizations and can safely be immunized without stopping their anticoagulation therapy. NACI also recommends that individuals with a bleeding disorder should ensure that their condition is optimally managed before immunization which may require consultation with their treating health care provider.

The National Advisory Committee on Immunization (NACI) currently recommends that people wait for at least 14 days after being given another vaccine (e.g. the influenza vaccine) before receiving the mRNA COVID-19 vaccine. The Pfizer BioNTech and Moderna vaccines are both mRNA vaccines. NACI also recommends that people wait for 28 days after receiving an mRNA COVID-19 vaccine before getting another vaccine. In summary, the COVID-19 vaccine should be given 14 days after receiving any previous vaccine and additional vaccines should not be given for 28 days after the COVID-19 vaccine. 

Finally, NACI does not recommend that COVID-19 vaccines be given at the same time as other vaccines.