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Healthcare workers from Humber River Hospital draw out doses of the Moderna Covid-19 vaccine before administering the vaccine to residents at a LOFT community housing complex in Toronto on March 26, 2021.COLE BURSTON/AFP/Getty Images

Janet Rossant is president of the Gairdner Foundation, which rewards excellence in research affecting human health. Heidi Larson is founding director of the Vaccine Confidence Project at the London School of Hygiene & Tropical Medicine. She is speaking at Gairdner’s Vaccination: Moving Forward with Confidence event on March 30.

The production of multiple effective vaccines against the COVID-19 virus in less than a year has been a remarkable success story of scientific and industry collaboration. The next vital step to address the health and economic devastation caused by the pandemic will be ensuring the broad distribution and uptake of these COVID vaccines. Mistrust in vaccines, particularly with the fast-paced development of current candidates, has been amplified by misinformation on social media and threatens to hold back successful vaccine rollouts worldwide. To move forward, the extraordinary science of the vaccines must be supported by an understanding of vaccine hesitancy and the rebuilding of trust across societies to ensure a safe and healthy post-pandemic world.

Since 2010, the Vaccine Confidence Project has mapped out trends in public opinion on vaccination. The Project has revealed large national differences in overall confidence in vaccine importance, efficacy and safety, and mapped the unique changes related to local events and government actions. For example, overall confidence levels in vaccination fell dramatically in the Philippines between 2015 and 2018 after pharmaceutical company Sanofi reported that the new vaccine being used against dengue fever in the country could increase complication risks in those experiencing their first exposure to the virus, including children. One vaccine misstep can become a threat to the vaccination system as a whole.

Tracking Canada’s COVID-19 vaccine rollout plans: A continuing guide

Fundamentally, vaccine success is not just a matter of positive trial outcomes. The best science can be derailed by issues of mistrust in the institutions that influence vaccine development and delivery, including governments, the biopharmaceutical industry, health care systems, research science and the media.

Moderna, Pfizer, AstraZeneca or Johnson & Johnson: Which COVID-19 vaccine will I get in Canada?

Canada pre-purchased millions of doses of seven different vaccine types, and Health Canada has approved four so far for the various provincial and territorial rollouts. All the drugs are fully effective in preventing serious illness and death, though some may do more than others to stop any symptomatic illness at all (which is where the efficacy rates cited below come in).


  • Also known as: Comirnaty
  • Approved on: Dec. 9, 2020
  • Efficacy rate: 95 per cent with both doses in patients 16 and older, and 100 per cent in 12- to 15-year-olds
  • Traits: Must be stored at -70 C, requiring specialized ultracold freezers. It is a new type of mRNA-based vaccine that gives the body a sample of the virus’s DNA to teach immune systems how to fight it. Health Canada has authorized it for use in people as young as 12.


  • Also known as: SpikeVax
  • Approved on: Dec. 23, 2020
  • Efficacy rate: 94 per cent with both doses in patients 18 and older, and 100 per cent in 12- to 17-year-olds
  • Traits: Like Pfizer’s vaccine, this one is mRNA-based, but it can be stored at -20 C. It’s approved for use in Canada for ages 12 and up.


  • Also known as: Vaxzevria
  • Approved on: Feb. 26, 2021
  • Efficacy rate: 62 per cent two weeks after the second dose
  • Traits: This comes in two versions approved for Canadian use, the kind made in Europe and the same drug made by a different process in India (where it is called Covishield). The National Advisory Committee on Immunization’s latest guidance is that its okay for people 30 and older to get it if they can’t or don’t want to wait for an mRNA vaccine, but to guard against the risk of a rare blood-clotting disorder, all provinces have stopped giving first doses of AstraZeneca.


  • Also known as: Janssen
  • Approved on: March 5, 2021
  • Efficacy rate: 66 per cent two weeks after the single dose
  • Traits: Unlike the other vaccines, this one comes in a single injection. NACI says it should be offered to Canadians 30 and older, but Health Canada paused distribution of the drug for now as it investigates inspection concerns at a Maryland facility where the active ingredient was made.

How many vaccine doses do I get?

All vaccines except Johnson & Johnson’s require two doses, though even for double-dose drugs, research suggests the first shots may give fairly strong protection. This has led health agencies to focus on getting first shots to as many people as possible, then delaying boosters by up to four months. To see how many doses your province or territory has administered so far, check our vaccine tracker for the latest numbers.

Mistrust of the pharmaceutical industry is another factor in the vaccine trust landscape. People question whether the profit motive and the speed of production may have compromised the safety of new vaccines. In most cases, industry has aimed to counter this by openly reporting their processes, trials and results in ways that should serve them well in future clinical trial reporting. They should also be recognized for examples of cross-company collaborations to speed up vaccine development, such as GlaxoSmithKline providing its best adjuvant to help any vaccine developer and the recent agreement by Merck to produce the Johnson & Johnson vaccine to speed up delivery in the U.S.

Health care systems sometimes forget that they, too, are not always the trusted deliverer of health interventions. Access to health care is not fully equitable across socio-economic strata, including in the Canadian universal health care system. Systemic racism is endemic and only now being appropriately recognized and responded to. Government-led mass vaccination efforts can be a source of concern to racialized and Indigenous communities with generational memories of past unethical government-sanctioned experiments, as well as current concerns in countries with poor human rights records. Rebuilding trust requires providing non-medicalized delivery systems and targeted informational content through engagement with community leaders.

Science has generally done well in public perception during the COVID crisis. The innovative vaccines developed over the past year demonstrate how creative minds can converge from different directions to tackle a major health challenge. Scientifically gathered and interpreted evidence has been behind most of the public-health recommendations that we adhere to today. But premature reports of possible treatments for COVID without supporting evidence have damaged the reputation of the field. Scientists need to promote the principles of open science by sharing data, techniques and results to provide the most robust evidence base for COVID vaccines and interventions. The remarkable global collaborations underlying our current knowledge base on the COVID virus should be an exemplar for future initiatives to tackle the next big global challenges, and a point of pride in the scientific community.

Social media is a constant source of both information and misinformation on COVID and vaccines. Groups engage through different threads and platforms, making broad counter-efforts challenging. However, that should not discourage efforts to distribute trustworthy, scientifically credible and culturally appropriate content to encourage vaccine uptake. Efforts such as Science Up First, COVID-19 Resources Canada, and 19 To Zero need to be amplified, modified and expanded toward diverse audiences to increase vaccine confidence across society.

Despite these challenges, we see the successful rollout of vaccines in an equitable manner as a real opportunity to regain broad-based trust in the individuals and institutions that affect the health and well-being of people worldwide. We can move from a medicalized perspective on public health to an integrated wellness and equity lens that will promote public confidence in the future and demonstrate our shared ability to respond effectively to the next grand challenges.

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