Lower risk of myocarditis observed after mRNA vaccine booster dose
A CITF-funded study published in the International Journal of Infectious Diseases reaffirmed that myocarditis following a mRNA COVID-19 vaccine is rare. Furthermore, the myocarditis rate following a third mRNA dose is lower than after the second dose.
Kids’ time spent on screens and outdoor activity affected by lockdown stages of the COVID-19 pandemic
A CITF-funded study, published in the Journal of Physical Activity and Health, found that children under 5 years of age had greater increases in screen use, but lower increases in physical activity and outdoor play time compared to children between the ages of 5 and 12 during COVID-19 lockdowns. This study was led by Dr. Jonathan Maguire (University of Toronto).
Risk of myocarditis or pericarditis remains low in adolescents after Pfizer-BioNTech vaccination
A CITF-funded study, published in JAMA Pediatrics, reported that among adolescents the risk of myocarditis or pericarditis after receiving the monovalent Pfizer-BioNTech mRNA vaccine varies according to age and sex. There is some evidence to suggest an increased risk with shorter intervals between doses 1 and 2.
In children, longer dosing intervals increase the effectiveness of vaccines but protection wanes fast
In this CITF-funded study published in Pediatrics, Drs. Jeffrey Kwong (University of Toronto) and Kumanan Wilson (University of Ottawa) highlighted that two doses of the monovalent Pfizer-BioNtech mRNA vaccine yielded moderate protection against symptomatic SARS-CoV-2 infection, while protection against severe COVID-19 outcomes was much higher among children between the ages of 5 and 11.
In people aged 50 years or older, booster doses sustain the protection against Omicron-related severe outcomes for at least three months
In this CITF-funded study, published in Nature Communications, Dr. Jeffrey Kwong (University of Toronto), along with Drs. Kumanan Wilson and Deshayne Fell (University of Ottawa) found that a third and fourth dose of mRNA vaccine sustained the protection conferred against severe Omicron-related outcomes for at least three months in people aged 50 years or older.
Blood donors aged 17-24 years old and racialized groups continue to have higher seroprevalence
In its latest CITF-funded seroprevalence report, Canadian Blood Services suggest that 77.3% of blood donors had infection-acquired antibodies by mid-February.
Characteristics of Quebec plasma donors used to study COVID-19 immunity
CITF-funded researchers at Héma-Québec, led by Drs. Marc Germain and Renée Bazin, published a paper in BMJ Open reporting on the characteristics of the plasma donors whose samples are used to study COVID-19 immunity in Quebec. More than 86,000 plasma samples have been collected from more than 15,500 individual donors in its COVID-19-focused PlasCOV biobank.
Vaccine hesitancy among parents of children and teens 5-18 years old
A CITF-funded study published in the Canadian Medical Association Journal (CMAJ) discussed how parents’ experiences making decisions regarding SARS-CoV-2 vaccines for their children were complex, even for those who were supportive of vaccination. The study was led by Drs. Jonathan Maguire and Janet Parsons (University of Toronto). This research is part of the TARGet Kids! (Applied Research Group for Kids) Study.
Booster doses are efficient at mounting strong T-cell immune responses in people living with HIV
In a peer-reviewed paper published in Viruses, a CITF-funded study led by Dr Mohammad-Ali Jenabian (Université du Québec à Montréal, UQAM), along with Dr. Aslam Anis (University of British Columbia) found that a third dose of COVID-19 vaccines induced robust cellular immune responses in people living with HIV that are comparable to what is observed in individuals without HIV.