The latest data from Canadian Blood Services show the rapid increase in infection-induced immunity began slowing by mid-March. The data show infection-acquired seropositivity increased moderately between the end of February and mid-March, up to 27.5% from 25.3%.
CITF-funded researchers Drs. Jeff Kwong from the University of Toronto, Gaston de Serres from l'Institut national de santé publique du Québec, and Mel Krajden of the University of British Columbia, found that two doses of mRNA or viral vector (Astra Zeneca) vaccines provide excellent protection against severe outcomes (hospitalization or death) from COVID-19.
This pre-print study, not yet peer-reviewed, led by CITF-funded researcher Dr. Brian Grunau from the University of British Columbia, aimed to identify the optimal interval between mRNA vaccine doses to generate the maximum immune response.
This systemic review, released in a preprint that has not yet been peer reviewed, estimated that seroprevalence in Africa (due to infection or vaccination) rose from 3% in Q2 2020 to 65.1% in Q3 2021.
In a recent newsletter released on their website, CITF-funded researcher Dr. Prabhat Jha and his Action to beat Coronavirus (Ab-C Study) team report findings on the third phase of their study covering data up until October 2021, prior to the Omicron wave.
In a pre-print, not yet peer reviewed, the team from the STOP-CoV study, led by Dr. Sharon Walmsley from the University Health Network in Toronto, described their most recent findings: younger adults (30-50) generate higher levels of vaccine-specific antibodies compared to older adults (70 and above) after both the first and second mRNA vaccine doses.
CANVAS-COVID tracks the safety of COVID-19 vaccines through electronic surveys sent to people who have been vaccinated. Over 1.3 million individuals have contributed data so far.
To help inform vaccine safety monitoring efforts, a team 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 order to help public health authorities and clinicians to contextualize observed events of vaccine-induced immune thrombotic thrombocytopenia (VITT) - an extremely rare but serious blood clot following immunization with the AstraZeneca/Vaxzevria COVID-19 vaccine - the Canadian Immunization Research Network (CIRN), including CITF-funded researcher Dr. Jeff Kwong, sought to estimate background rates of selected thromboembolic and coagulation disorders in Ontario from 2015-2020.
A study carried out by SeroTracker (a CITF-funded project) in partnership with the World Health Organization, found global SARS-CoV-2 seroprevalence (due to infection or vaccination) was 26% in April 2021. Depending on the region, seroprevalence varied from as low as 1.6% to as high as 57%.