Ask Your Pharmacist

November 19, 2020

I’ve heard there is a vaccine for COVID-19 coming. What can you tell me about its development and when we might expect to see it?


Recent news regarding Pfizer’s breakthrough development of a vaccine active against COVID-19 is a potential game changer for the pandemic. I did a little digging and found some information from the World Health Organization (W.H.O) which I hope you find useful. There are currently more than 100 COVID-19 vaccine candidates under development, and as of November 14, 2020, the W.H.O lists 17 potential COVID-19 vaccines in phase III human trials.

Potential vaccines use different approaches to teach the body’s immune system to safely recognize and block the virus that causes COVID-19. Some mechanisms use inactivated or weakened forms of the virus so that it doesn’t cause disease, but still generates an immune response. Protein-based vaccines use harmless fragments of proteins or protein shells that mimic the COVID-19 virus to safely generate an immune response. Viral vector vaccines use a virus that has been genetically engineered so that it can’t cause disease, but produces coronavirus proteins to safely generate an immune response. RNA and DNA vaccines use a cutting-edge approach that uses genetically engineered RNA or DNA to generate a protein that itself safely prompts an immune response.

One such RNA vaccine, an mRNA vaccine, was developed by scientists in collaboration with Pfizer. Researchers conducted a study in Germany and the United States (at 155 sites) using an mRNA - based vaccine known as BNT162. In the study, 43,998 otherwise healthy individuals, aged 12 to 85 years of age, with COVID-19, received two intramuscular injections (21 days apart) of vaccine or placebo. Recruitment of individuals to receive the vaccine began April 22, 2020. Interim results show that the vaccine has 90 per cent efficacy with low incidence of serious side effects. The study will follow patients for two years after the last dose of vaccine, that is until December, 2022. 

While the early results for vaccine BNT162 are very promising for this vaccine, it is important to remember however that the final results of the study are some time off. There are still questions to be answered. We want to be certain that any vaccine administered to the population is safe, that the effects on immunity last over time, and that the incidence of adverse effects is low. In addition, the BNT162 vaccine has a storage temperature of minus 70 degrees Celsius. Maintaining this cold chain from manufacturer to patient will require careful logistical planning. The vaccine also requires two doses. Vaccine approval in Canada undergoes a rigorous process regulated by Health Canada under the Food and Drugs Act. Data obtained from clinical trials done on tens of thousands of individuals will be thoroughly reviewed by Health Canada scientists to confirm there are no significant safety concerns and to determine that the vaccine is able to adequately protect against disease. In a public health emergency, such as the COVID-19 pandemic, special authorizations are used expedite this process and allow emergency access to a vaccine as soon as it is safe to do so. 

In August, Canada purchased from Pfizer 20 million doses of this mRNA-based vaccine. Officials have said it is possible that the vaccine will be available to the public during the first part of 2021. Several other vaccine candidates are also in the front running to reach the Canadian market in the coming months.

When immunization is finally available, individuals at highest health risk will be prioritized to be immunized against COVID-19. It is expected that pharmacists and other health care professionals will work with Public Health on the important task of safely immunizing the public against COVID-19.

All of this news gives us hope. “Hope begins in the dark, the stubborn hope that if you just show up and try to do the right thing, the dawn will come. You wait and watch and work; you don't give up.” – Anne Lamott

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