Was the COVID-19 vaccine rushed and what are the side effects? CBC asked an expert

Was the COVID-19 vaccine rushed and what are the side effects? Matthew Miller, an associate professor of infectious diseases and immunology at McMaster University in Hamilton explains. For the full interview watch the video at the bottom of the story.

Was the COVID-19 vaccine rushed and what are the side effects?

Matthew Miller:

So, the reality isthat although the development timeline for this specific vaccine against COVID has been very rapid, the nature of the clinical trials and what's expected from a safety perspective is the same as any other vaccine.

Another important consideration that I don't think has been, really, sufficiently discussed is that these vaccines have also been tested in early phase clinical trials for lots and lots of other indications. So, whilethis is the first MRNAvaccine that will be widely available to the public it's not like our experience with these vaccines is limited to the last 11 months in terms of our understanding of safety. Another important thing to know about vaccines is thatthe vast majority of adverse reactions that happen in response to vaccines are acute adverse reactions. So, that means they happen in close proximity to getting the dose itself. And the vast majority of those are are allergic or inflammatory.

So, some people have allergies to the components of vaccines. They break out with a rash. In very, very, very rare cases people may experience a serious anaphylactic allergy. And so those extremely rare events happen almost right after you get the vaccine. Long term consequences are extremely rare, and the reason for that is because vaccines are intrinsically different from other drugs in that after the dose is administered, all the vaccine does is teach our immune system to do what it does every day in response to the literally millions of of microbes and pathogens that we're exposed to in the environment.

Some some long term consequences that you hear about, although they're very, very rare in response to vaccines, are things like Guillain-Barre syndrome and sometimes Bell's Palsy. While we don't fully understand how those conditions happen in in even outside of the context of vaccines, the evidence so far suggests that essentially there are shapes on pathogens which look like shapes in our body.

Our immune system essentially works by recognizing shapes. And so in response to a vaccine, sometimesthe pathogen against which were vaccinated has a shape that looks like a shape in our own body and so our body gets confused and can mount a response against our own cells. But what's critically important to remember is that this same response happens if you were to be infected by the pathogen itself. And it's almost always the case that the rate of those adverse events like Guillain-Barre syndrome or Bell's Palsy are much, much higher in infected individuals.

So, although vaccines can in very rare instances cause these these side effects, in the long term, those rates are much lower than if you were to be infected, which is to say that essentially the vaccine lowers your risk relative to having been infected.

Watch the full interview with Matthew Miller below.

How does the COVID-19 vaccine work and how safe is it? CBC Asks an infectious disease scientist

4 years ago

Duration 27:57

Matthew Miller, an associate professor of infectious diseases and immunology at McMaster University in Hamilton, takes your questions about the COVID-19 vaccine.