COVID-19 Vaccine FAQ

How does the vaccine work?

The Pfizer and Moderna vaccines are the ones you are most likely to receive in our area.  Both vaccines are mRNA vaccines.

Think of your immune system like a police force, trying to protect you from a criminal (the COVID virus).  The mRNA acts like a wanted poster – it shows your immune system an image of what COVID-19 looks like.  It does NOT contain any actual virus, so it is impossible to catch COVID from the vaccine.  The police (your immune system) learns what COVID-19 looks like from the mRNA wanted poster, and makes antibodies against COVID-19 based on this image.  The mRNA breaks down quickly – like the posters being taken down – so nothing from the vaccine stays in your system in the long term.  It does not affect any of your own DNA.  However, the antibody memory remains, so that if the criminal (COVID virus) breaks in, your immune system can recognize quickly and fight it off without producing serious symptoms.

I’ve heard people don’t feel well after the vaccine – is that true?

The process of recognizing the mRNA and making antibodies requires your immune system to respond to the mRNA.  An immune response can include fatigue, fever, muscle aches – this is a sign your body is reacting to the vaccine and making antibodies to protect you.  Not everyone will get noticeable symptoms, but if you do, be reassured that this is a normal temporary immune system response and will go away over the next 24-48h.  

There is a chance you could be allergic to the vaccine, which is different from the normal immune response.  Allergic reactions to the vaccine components could produce hives, swelling of the face and lips or trouble breathing. If this happens, you should seek medical attention.  You will be asked to wait for 15-30 minutes after your vaccine to monitor for any reaction.

I’m worried because it’s so new – how could they make it so fast?

When making most vaccines, scientists have to try to prevent an illness that is already rare.  You can imagine for a disease like Ebola, when there are exceedingly few cases occurring at any given time, it takes a very long time to accumulate enough cases to prove the vaccine works.  In the case of COVID, however, the number of cases was so high that it did not take long to detect that the vaccine was preventing infections.

Similarly, it is often quite difficult to recruit participants in trials for vaccines, but for COVID, many people were willing to participate in the vaccine trials, so the studies were able to be done in appropriate numbers much faster than average.

From the vast majority of existing vaccines, we also know that most side effects from a vaccine will occur within the first 6-8 weeks after receiving it.  Since this vaccine has been out longer than that, we can be reassured that common issues would likely have already been detected.

Additionally, while these vaccines are the first mRNA vaccines to be approved for widespread use, human trials of mRNA vaccines for other viruses have been conducted for at least 10 years, so the technology is not brand-new.

Why should I get vaccinated?

It can be scary to get the vaccine because it feels unknown.  

We do know, however, that the risk of acquiring COVID, both in the short-term and the long term (like long COVID), is real.  Risk factors like age and underlying conditions make serious infection and death a possibility, and for reasons we can’t always predict, even healthy young people have developed serious infections from this illness.

We also know that we will be stuck in cycles of lockdown and reopening until rates of serious infections go down and stay down.  The healthcare system capacity will continue to be threatened as long as COVID cases add burden to the emergency rooms, the wards and the ICUs.  Vaccination significantly lowers the rate of serious COVID infections, which reduces health care burden, and is the best way to make sure the health care system can re-open.  A return to normal life and normal healthcare is essentially dependent on as many people getting vaccinated as possible.  

Who shouldn’t get it?

Current recommendations state that you should NOT get the Pfizer or Moderna vaccine if:

  • You had an anaphylactic reaction to the first dose of the vaccine.
  • You have a confirmed allergy to a component of the vaccine.
  • You currently have suspected or confirmed COVID (you can get the vaccine when you have recovered).
  • You are acutely ill (as a precautionary measure).
  • You have received another vaccine in the last 14 days.
  • You are under the age of 18 (not tested yet).

You should TAKE PRECAUTION with (and consider discussing with your doctor about how to safely receive) the Pfizer or Moderna vaccine if:

  • You have a bleeding disorder or are on a blood thinner.
  • You are prone to fainting.
  • You have had a serious or anaphylactic allergic reaction to another vaccine, a medication, or a food.
  • You are pregnant or breastfeeding.
  • You are immunocompromised or on immunosuppressive medications.
  • You have a suspected allergy to a vaccine component.

Can I get the vaccine if I am pregnant or breastfeeding?

It is worth discussing this with your physician.  

The recommendations from the Society of Obstetricians and Gynecologists of Canada (SOGC) are that women who are pregnant or breastfeeding should be offered vaccination at any time if they are eligible and no contraindications exist.  

More details can be found here (

Will I still need to wear a mask and social distance after I get my vaccine?

As far as we know for now – yes.

The vaccine protects you from getting a serious case of COVID if you are exposed.  However, if you are exposed to COVID, while you are much less likely to get sick yourself, you could still transmit the virus to someone else who isn’t vaccinated.  

As such, for the time being, you will need to continue to mask and distance to avoid spreading COVID to others until a substantial number of people have been vaccinated.

How will I be notified?

The province of Ontario receives the vaccines and distributes them to the individual Public Health Units (PHUs) who then create a plan for distribution.  

Our local Public Health Unit frequently updates their vaccine information, located here:

They currently have a sign-up tool to make sure they know to notify you when you are eligible to receive a vaccine based on your age category, found here:

Our office is also in contact with the Hastings-Prince Edward PHU for updates.  We anticipate that the PHU will make announcements to the public (for example, through radio and local news sources) as vaccines become available.  It has not yet been determined where, when and how the vaccine will be distributed to the general public.  We will also update our phones and website as we know more.

Leave a Comment