Information for the Public: Everything You Need to Know About the COVID Vaccines

Gabrielle Busque

January 14, 2021

A reliable and up to date information source about the COVID vaccine.

Which COVID vaccines are available in Canada?

As of January 12th, 2021, the Pfizer-BioNTech and Moderna COVID vaccines have been approved for use in Canada. Two additional COVID vaccines are under review by Health Canada, they are vaccines by AstraZeneca-Oxford and the Janssen.

How do the COVID vaccines work?

mRNA vaccines: Pfizer-BioNTech & Moderna

mRNA vaccines are made of genetic material called messenger RNA (mRNA) surrounded by a fatty outer layer. This mRNA contains instructions for your cells to make a piece of the spike protein found on the novel coronavirus. When you are vaccinated, this mRNA code enters the muscle cells in your arm where you were injected. Your cells can then use this code to make the coronavirus spike protein and show it to the immune system by displaying it on their cell surface. The immune system begins activating processes to fight off what it believes is an infection, including producing antibodies. Since these antibodies are specific for the novel coronavirus spike protein, the immune system will know how to protect you against the virus if you become infected later on.  


Viral vector vaccines: Oxford-AstraZeneca & Janssen


Viral vector vaccines consist of genetic material (double stranded DNA) for the novel coronavirus spike protein which has been inserted into a safe virus which can infect humans without causing disease. The safe virus carries the DNA for the coronavirus spike protein into muscle cells of the vaccinated arm, which can be read by the cell to build the spike protein. Your cells can then use this code to make the coronavirus spike protein and show it to the immune system by displaying it on their cell surface. The immune system begins activating processes to fight off what it believes is an infection, including producing antibodies. Since these antibodies are specific for the novel coronavirus spike protein, the immune system will know how to protect you against the virus if you become infected later on.  

How many doses are required?

  • Pfizer-BioNTech: 2 doses
  • Moderna: 2 doses
  • AstraZeneca: 2 doses
  • Janssen: 1 or 2 doses (trials ongoing) 

Why do most of the COVID vaccines need a second dose?

The Pfizer-BioNTech, Moderna, and AstraZeneca vaccines all require two doses to fully prepare the immune system to protect against COVID-19. The first dose primes the immune system to recognize the coronavirus, and the second dose boosts the immune response against the coronavirus. The first dose provides some protection, but the second dose provides the highest, most durable immunity against COVID-19 shown in the vaccine studies.  

It is important to note that it is not uncommon for vaccines to require more than 1 dose. Several childhood immunizations require two or more doses to be effective. In fact, when a child gets their first influenza vaccine, or flu shot, they need two doses to ensure that they are protected since their immune system has not seen the influenza virus before. The first dose primes the immune system to recognize the influenza virus, and the second dose boosts the immune response against influenza virus. 


How effective are the vaccines currently available in Canada?

The Pfizer-BioNTech and Moderna vaccines demonstrated excellent efficacy against COVID-19 in the two-dose vaccine trials. Additional data analyses have also demonstrated considerable efficacy after a single dose of these vaccines. However, both doses remain highly important to ensure the most robust and lasting immunity against COVID-19.

How soon will I be protected?

After you are vaccinated, it will take 1 to 2 weeks for your body to build an immune response against the virus, meaning that you will not be protected right away. Your first dose will confer some immunity against the coronavirus, and your second dose will confer the highest, most durable immunity. However, no vaccine is 100% effective. It is therefore extremely important to continue wearing a mask and practice social distancing to prevent yourself or others from getting sick. 


What side effects can I expect from the COVID-19 vaccine?

Side effects may vary depending on which vaccine you get. With the currently available data, the most common side effects to the COVID-19 vaccines include injection site pain, redness at injection site, fatigue, headache, muscle pain, chills, joint pain, and fever. These side effects are all symptoms of the immune system kicking into gear, which means the vaccine is working. Side effects are usually mild to moderate, but they tend to be a bit more common and intense after the second dose since the body’s immune system is already primed against the vaccine. Vaccine side effects subside within a few days and can be managed with acetaminophen (Tylenol). 

Why should I get vaccinated?

COVID-19 is a highly contagious disease which can have serious, life-threatening complications. There is no way to know how it will affect you or those in close contact to you. By wearing masks and practicing social distancing, you decrease your chance of being exposed to the virus or spreading it to others, but these measures are not always effective. Getting vaccinated helps your body build immunity to the virus and decreases the likelihood that you get sick. 


Should I still get vaccinated if I already had COVID-19?

At this time, we are unsure how long someone is protected after getting sick and recovering from COVID-19. Natural immunity varies from person to person, and it may not last very long. Due to the possibility of re-infection and the severe health risks associated with COVID-19, people who have gotten sick with COVID-19 may still benefit from getting vaccinated.


I already received the COVID-19 vaccine. Do I still need to wear a mask, practice social distancing, and wash my hands frequently?

We all hope that the world will eventually return back to normal. However, it is highly important that you keep wearing a mask, practicing social distancing, and washing your hands as you were prior to getting vaccinated. After getting the vaccine, it will take some time for your immune system to mount a response against the coronavirus, which means that you will not be protected against the virus right away. Whether vaccinated individuals can still contribute to the spread of the virus to others is still largely unknown. It will take some time for the population to get vaccinated, so it is important to continue these practices to prevent the spread of COVID-19 to those who have not been vaccinated.

Can I get COVID-19 from the vaccine?

No, the COVID vaccines do not contain the live coronavirus and therefore cannot give you COVID-19.


Illustrations by: Gabrielle Busque


References:

WRITTEN BY:

Gabrielle Busque

Gabrielle is a 4th year pharmacy student at the University of Toronto. At MedMe, Gabrielle is heavily involved in drug/medical information and design. She is passionate about optimizing the delivery of clinical services in pharmacies to advance patient care.

MedMe is a thought leader and software provider in pharmacy care

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