CITF-funded findings on vaccine safety and effectiveness
CITF-funded studies show the important role that vaccines have played in protecting Canadians and people worldwide from severe COVID-19. Here, we summarize results from the five presentations given during the breakout session “Vaccine safety and effectiveness” at the CITF Scientific Meeting in Vancouver, March 8-10, 2023.
Omicron breakthrough infection instills higher and more broadly neutralizing immune responses against SARS-CoV-2 variants than a booster dose alone
A CITF-funded study, published as a preprint and not yet peer-reviewed, found that individuals with two vaccine doses and an Omicron breakthrough infection produced higher salivary SARS-CoV-2 IgA antibodies against Spike and RBD than individuals with three vaccine doses and no breakthrough infection.
COVID-19 vaccination does not increase risk of adverse events or healthcare use in people with rheumatoid arthritis
A CITF-funded study, published in Journal of Rheumatology, provides reassurance that COVID-19 vaccination in individuals with rheumatoid arthritis (RA) does not increase overall risk of adverse events of special interest (AESI).
COVID-19 was the primary cause of hospitalization for half of hospitalized patients who tested positive for SARS-CoV-2
A CITF-funded study, published in PLos One, found that among patients admitted to hospital who tested positive for SARS-CoV-2 during the Omicron wave, 52% had a primary diagnosis of COVID-19 and the others had incidental SARS-CoV-2 infections.
Pfizer (BA.4/BA.5) and Moderna (BA.1) bivalent vaccines induce similar neutralization against Omicron subvariants
A CITF-funded study, published in Nature Communications, found that Pfizer (BNT162b2 (BA.4/BA.5)) and Moderna (mRNA-1273 (BA.1)) bivalent vaccines induced similar neutralization to each other against Omicron subvariants BA.1, BA.5, BQ.1.1, and XBB.1.5 in patients on dialysis or with a kidney transplant, despite being antigenically divergent from strains circulating at the time.
Seroprevalence due to infection continued to be stable near the 80% mark in August
The latest CITF-funded report from Canadian Blood Services suggested that seroprevalence due to infection was 79.03% among Canadian blood donors in August 2023.
CITF-funded findings on methodologic approaches to improve seroprevalence estimates
Assessing seroprevalence is the main methodology used in Canada and around the world to determine the extent and trends in SARS-CoV-2 immunity, whether from infection, vaccination, or both.
CITF-funded findings on COVID-19 and vaccine effects on pregnancy and infants
CITF-funded studies have confirmed that COVID-19 is indeed more severe in many pregnant people, and that pregnant people and their babies respond just as well as the general population to COVID-19 vaccines.
Profiling a cohort of retail workers in Quebec to study the COVID-19 immune response
A CITF-funded team studied the risk to grocery store, hardware store, bar, and restaurant workers during the COVID-19 pandemic. This cohort profile preprint article, not yet peer-reviewed, describes participant demographic, socioeconomic, behavioural, clinical, and occupational characteristics, as well as whether participants tested positive for SARS-CoV-2, experienced any COVID-19 symptoms (where applicable), and were vaccinated.