Seroprevalence provides an accurate measure of SARS-CoV-2 infection compared to PCR testing
A CITF-funded study, published in the CMAJ Open, found that seroprevalence data is a very useful mechanism to obtain accurate measures of the prevalence of SARS-CoV-2 infection in the population, and when compared to PCR testing which under detects the number of infections was more reflective of the true burden.
Fourth vaccine dose helps protect solid organ transplant recipients from circulating Omicron subvariants
A CITF-funded study, published in Clinical Infectious Diseases, reported that a fourth vaccine dose significantly increases BA.4/5-specific neutralizing antibodies, as well as CD4+ T cell responses in solid organ transplant recipients (SOTR).
Youngest blood donors (aged 17-24) and people who are racialized continue to have higher seroprevalence
The latest CITF-funded seroprevalence report from Canadian Blood Services showed that seroprevalence due to natural infection was 77.6% at the end of February.
Different modelling approaches able to predict SARS-CoV-2 cases
In a preprint, not yet peer-reviewed, CITF-funded researchers found that machine learning and epidemic transmission modelling could accurately predict cases of SARS-CoV-2 infection during the Omicron wave.
Protocol: strength and duration of immune responses to COVID-19 vaccines in people living with chronic kidney disease (CKD)
This paper, published in the Canadian Journal of Kidney Health and Disease by CITF-funded researchers Drs. Matthew Oliver and Michelle Hladunewich (Sunnybrook Health Sciences Centre), presents the protocol for a new study aimed at characterizing the strength and duration of immune responses to COVID-19 vaccines in people living with chronic kidney disease (CKD).
Seroprevalence studies are important for assessing the occupational risk of COVID-19
A systematic review published in BMJ Open, drawing on data from the CITF-funded Serotracker initiative led by Dr. Rahul Arora (University of Calgary), highlights that SARS-CoV-2 seroprevalence varied widely across occupations during the first year of the pandemic.
Vaccinated mothers protect infants to a greater degree against Delta than Omicron
A CITF-funded study published in JAMA Pediatrics found that the infants of mothers who were vaccinated postpartum had moderately effective protection against Delta infection (73%), but little protection against the Omicron variant (13%). The study applied to infants below the age of six months.
Establishing an immune protection threshold is essential to optimize and individualize SARS-CoV-2 vaccination
A CITF-funded study published in Transplantation aims to identify correlates of protection that would be necessary to safeguard against various SARS-CoV-2 variants. Researchers found that a binding antibody concentration of less than 752 binding antibody units (BAU/mL) resulted in poor immune protection against Omicron, whereas levels over 1357 BAU/ml resulted in 100% neutralization against Omicron.
Third and fourth vaccine doses broaden and prolong immunity to SARS-CoV-2 in adults with IMIDs
A CITF-funded study, published in preprint and not yet peer-reviewed, demonstrates that third and fourth doses of vaccine sustain and broaden immune responses to SARS-CoV-2 in adults with immune-mediated inflammatory diseases (IMIDs). The authors conclude that this supports the recommendation for three- and four-dose primary series vaccine regimens in this population.