Ask Your Pharmacist

March 24, 2021

If I have an opportunity to get the Astra Zeneca vaccine, should I take it? I’ve heard this vaccine causes blood clots and isn’t as effective as some of the others.


It’s normal to have these sorts of doubts. It means you are taking this decision seriously. I received my first dose of COVID-19 vaccine this weekend, and I admit I was nervous. I did feel flu-like the evening after I received the dose, but the next day, I was none the worse for wear.

Get the first vaccine offered to you. We are still very much in the midst of a public health crisis. Much of Europe is experiencing a third wave COVID-19 and case counts in Ontario are on the rise again.

We have been hoping and praying for a vaccine for a year now, and it is a true medical feat to have three effective and safe vaccines available to Canadians. I am frustrated with media coverage about vaccine safety that is not based on evidence.

Health Canada and the National Advisory Committee on Immunizations are two health advisory bodies composed of world-renowned scientists and expert clinicians. Their sole purpose is to protect public health. Every recommendation they make is the result of painstaking and rigorous examination of scientific data through the lens of public safety and medical effectiveness. If they say it’s safe, it’s safe. They say all the approved vaccines are safe.

One of the challenges in comparing the effectiveness of the different available vaccines is that the scientific outcomes of studies were not exactly the same. This makes the effectiveness of the three available vaccines appear quite different. Let’s have a closer look at important outcomes for individual New Brunswickers: serious illness, hospitalization, and death. All three vaccines are approximately equal - 80 per cent effective at preventing these outcomes.  

Now let’s look at safety and the much-reported risk of clots with the Oxford University – Astra Zeneca vaccine. The commotion began when the European Medical Agency, which regulates vaccines in Europe, put a hold on this vaccine after 25 cases of blood clots including nine deaths were reported. These cases came out of 20 million people who were immunized with the Oxford University – Astra Zeneca vaccine in Europe and Britain. Most recently, that same regulator gave the green light to continue use of the vaccine because no cause linking the blood clots to the vaccine’s administration could be found. Blood clots happen naturally in the population. It is required in Canada that any adverse event following in immunization be reported. Every day, we are watching for any sort of signal of a vaccine safety concern to the public. Over 335 million doses of COVID-19 vaccinations have been administered according to the World Health Organization (WHO).  The WHO considers the vaccines safe and effective at protecting the public against COVID-19.     

Pharmacists are happy to take the time needed to answer your questions about safety and effectiveness of COVID-19 immunizations. We will not be entertaining vaccine shopping, however. We are laser-focused on getting immunizations in the arms of New Brunswickers so that we can end this public health crisis. Every time we field a phone call about what vaccine our pharmacy is expected to receive, it takes away from time to vaccinate you, your loved ones, and our community. Given that all three vaccines are safe and effective, this is time we do not have.

I want to send a shout out to my New Brunswick pharmacist colleagues who have answered the call and are beginning to vaccinate our citizens. The task of immunizing so many New Brunswickers is daunting but we will get there one immunization at a time. To the public: we are privileged and excited to help end this pandemic through immunization. And we are tired. We are not complaining, but please remember during your interactions with us: we have been through the pandemic WITH you. It happened to us too. We have had no break. We are fully prepared and determined to do this, but your patience and kindness will help make our task easier. Get whatever vaccine is offered to you.

Dr Kevin Duplisea (PharmD BSc. Pharm, BSc. ACPR) is a pharmacist at Sharp’s Corner Drugstore in Sussex, New Brunswick. His opinions expressed in this newspaper are published for educational and informational purposes only, and are not intended as a diagnosis, treatment or as a substitute for professional medical advice, diagnosis or treatment. Send your questions to