Hybrid immunity conferred stronger immune responses in children and adults than vaccination alone
A CITF-supported study, published in preprint and not yet peer-reviewed, found that two doses of mRNA vaccine (Pfizer or Moderna) produce robust antibody responses three months post-vaccination in both children and adults. Additionally, hybrid immunity (immunity derived from the combination of SARS-CoV-2 infection and vaccination) conferred stronger immune responses in both age groups when compared to vaccination alone.
SARS-CoV-2 antibody levels increased in Canadian healthcare workers with each vaccine dose, but this waned over time
A CITF-funded study among Canadian healthcare workers, published in preprint and not yet peer-reviewed, found that SARS-CoV-2 anti-receptor binding domain (RBD) IgG levels increased following each COVID-19 vaccine dose and after the first SARS-CoV-2 infection.
Healthcare workers had higher incidences of SARS-CoV-2 infection and mental health conditions compared to the general population
A CITF-funded study, published in preprint and not yet peer-reviewed, found that healthcare workers (HCW) in Alberta had a higher incidence of SARS-CoV-2 infection and of mental health issues compared to community members (referents) seen in pre-pandemic physician consultations who were matched on gender, age, and geographic location. Excess infection was most notable early in the pandemic and during the fifth (Omicron) wave.
Each booster dose increases vaccine effectiveness against all Omicron subvariants
A CITF-funded study, published in preprint and not yet peer-reviewed, provided evidence that individuals with hybrid immunity (a combination of infection-acquired and vaccine-induced SARS-CoV-2 immunity) had nearly 90% protection against severe outcomes (hospitalization or death) during the Omicron BA.1/BA.2 and BA.4/BA.5 predominant periods.
Vaccination helps reduce Long COVID symptoms and down-regulates systemic markers of inflammation
A CITF-funded study, published in the International Journal of Infectious Diseases, explored whether COVID-19 vaccination in people with post-COVID-19 condition (PCC), also known as Long COVID, could affect their symptoms, immune responses, and viral persistence.
CITF-funded findings on breakthroughs in laboratory and in research infrastructure
Multiple platforms and novel technologies have been created over the past three years to aid Canadian clinical and research efforts in monitoring immune responses to SARS-CoV-2.
CITF-funded findings on immune responses to SARS-CoV-2 variants and hybrid immunity
CITF-funded studies continue to monitor immune responses to SARS-CoV-2 variants and increases in hybrid immunity among Canadians.
T-cell responses against Omicron variants BA.4/5 and XBB.1.5 in solid organ transplant recipients were robust after three doses of vaccine but lower than against the ancestral strain
A CITF-funded study, published in preprint and not yet peer-reviewed, found that vaccination induced robust SARS-CoV-2-specific T-cells responses against Omicron variant BA.4/5, in solid organ transplant recipients (SOTRs).
Retail and food workers with hybrid immunity had the highest neutralizing antibody levels against all SARS-CoV-2 strains
A CITF-funded study, published in preprint and not yet peer-reviewed, found that vaccination was associated with higher neutralizing activity (the ability of antibodies to block entry of the virus into the cell) against pre-Omicron variants than against Omicron sub-lineages.