You are not alone wondering about Covid-19 vaccines. There are two currently approved in Canada. As a retired paediatrician and former infectious disease specialist, I have been monitoring the pandemic and vaccine development with keen interest. I have looked into these vaccines, with their safety and efficacy data. Let me share this information with you.

The pandemic is caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). You may remember SARS that occurred in 2002-2004, killing many in Canada and in several other countries. That virus was called SARS- CoV-1. Because of its high mortality rate, strict isolation was enforced to prevent its spread. As a result, the epidemic was contained and stopped rather quickly, and life returned to normal in Canada. Unfortunately, a vaccine was not developed because the epidemic was very short.

SARS-CoV-2 is a much more infectious, but less lethal virus. Initially it killed mostly seniors and those with underlying health conditions, sparing young people. Over time, more young adults got sick, and required intensive care and ventilator support. Variant strains started showing up that are even more infectious.

The virus was first discovered in Wuhan, China. Within weeks, Chinese scientists were able to determine the genetic code of the virus and published it. Other scientists around the world recognized that the spike protein on the surface of this virus is crucial for infection. Teams of researchers worked around the clock, designing ways to induce immunity against this spike protein.

Two groups of scientists used the genetic code of the spike protein to produce artificial messenger ribonucleic acid (mRNA). They covered the mRNA with a fatty layer called nanoparticle that helps it to enter cells. Once inside, the cells produced spike protein based on the genetic information of the mRNA. The spike protein then goes to the surface of these cells, and stimulate our immune system to produce antibodies and other immune cells that can fight the virus. These are the first mRNA vaccines in the world, from Pfizer-BioNTech and Moderna.

In order to prove that these vaccines are safe and effective, they immunized thousands of adults in multiple countries where infection was widespread, and showed that both vaccines are more than 95% effective in preventing Covid-19 infections after two doses, with mild side effect.

When results came in, they were sent to regulatory agencies like Health Canada without delay. This reduced the normal wait time by weeks to months. No steps were skipped throughout the process. As a result, these mRNA vaccines were approved in December, and we started immunization in Canada shortly after. Since then, there were several reports of serious allergic reaction, all attributed to polyethylene glycol (PEG). PEG was used to keep the mRNA stable in the body after injection. As a result, those who have a history of severe allergic reaction to previous vaccinations are advised to wait for other Covid-19 vaccines that don’t contain PEG.

There are a number of other vaccines in development and testing, most of them employ different strategies to target the spike protein of the virus. We should see them being approved in the next while.

Because of this short timeframe, scientists were not able to involve children, pregnant women and nursing mothers, as well as those with weakened immune system in the original research. These groups are currently being tested in the same way, and we should have the answer in a few months.

I have heard rumours that these mRNA vaccines can change or harm our DNA. This is not possible. Our cells produce many mRNAs everyday from our own DNA; these mRNAs then code for the individual proteins that they are supposed to make. The process doesn’t go backwards. Although the mRNA vaccines are made artificially, it can only make the spike protein, and cannot reverse and change our DNA. These rumours are false; they are trying to scare us.

I hope this answered some of your concerns about the Covid-19 vaccines. At the present time, there is no plan to force anyone to get vaccinated. However, herd immunity requires more than 70% of the population with immunity against the virus, either through vaccination or infection. We can only get through this pandemic if most Canadians are immunized; we also need to vaccinate the rest of the world.