Vaccine surveillance

In a study published in the Canadian Medical Association Journal (CMAJ), Dr.  Zaeema Naveed (British Columbia Centre for Disease Control) and colleagues from the CITF-funded Canadian Immunization Research Network (CIRN) found that the rates of myocarditis following a COVID-19 vaccine have been low, and that age, sex and the type of vaccine administered are important factors to consider to further reduce the risk of post-vaccination myocarditis.

A paper by Drs. Naveed Janjua and Zaeema Naveed (British Columbia Centre for Disease Control), and CITF-funded researchers from the Canadian Immunization Research Network (CIRN), including Dr. Jeff Kwong (University of Toronto), published a paper in the Journal of the American College of Cardiology that evaluated the odds of developing myocarditis or pericarditis as a result of receiving two doses of either the Pfizer or Moderna mRNA vaccines against COVID-19.

Research stemming from the CITF-funded RECOVER study, published in Frontiers in Immunology, indicates that a two-dose primary series of vaccination is paramount for protection against COVID-19, even for those who were previously infected. Individuals who did not experience symptoms during their SARS-CoV-2 infection and had no antibodies to SARS-CoV-2 (negative serostatus) prior to vaccination show weaker immune responses to each vaccine dose than their symptomatic counterparts.

A CITF and Canadian Immunization Research Network (CIRN) funded study, published in Clinical Infectious Diseases, showed that adults who had a previous moderate or severe SARS-CoV-2 infection were more likely to experience side effects from the first vaccine doses.

A CITF-funded study published in Open Forum Infectious Diseases and led by Dr. Jeffrey Kwong (University of Toronto) on behalf of the Canadian Immunization Research Network (CIRN), highlighted that – prior to Omicron - the effectiveness of two doses of COVID-19 vaccine decreased over time against infection but remained high against severe outcomes over 11 months (January to November 2021).

A CITF-funded study led by Dr. Jeff Kwong (University of Toronto), published in JAMA Network Open, estimated that two doses of any COVID-19 vaccine were highly effective against a symptomatic Delta infection, but efficacy was lower and protection was more short-lived against a symptomatic Omicron infection.

Published in Clinical Infectious Diseases, CITF-funded researchers Drs. Jeff Kwong (University of Toronto), Gaston de Serres (L’Institut national de santé publique du Québec), and Mel Krajden (University of British Columbia), found that two doses of mRNA or viral vector ChAdOx1 (AstraZeneca’s Vaxzevria or COVIDSHIELD) vaccines provided excellent protection against severe outcomes (hospitalization or death) from COVID-19 during the period before the emergence of the Omicron variant.

A manuscript from a CITF-funded study in preprint (not yet peer-reviewed) by Drs. Marc Romney (University of British Columbia), Zabrina Brumme and Mark Brockman (Simon Fraser University), demonstrated that a third dose of an mRNA vaccine significantly enhanced the magnitude and durability of antibody responses, including among older adults (>70 years old) who remained COVID-naïve.

A study now published in Vaccine and led by CITF-funded researcher Dr. Jeff Kwong from IC/ES, tracked the incidence of nine different medical conditions in the five years preceding the pandemic (2015-2019) and in the first year of the pandemic (2020).

In a paper published in Frontiers in Public Health, CITF-funded researchers Drs. Pascal Lavoie, Louise Mâsse and Allison Watts, along with colleagues from the University of British Columbia, explored the factors associated with the intention to get the COVID-19 vaccine, as well as the sense of urgency to get vaccinated, among school staff.