General vaccine surveillance

Background rates for blood clotting events in Ontario provide context for COVID-19 vaccine safety assessment

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 [...]

2022-01-10T10:43:49-05:00January 10, 2022|General vaccine surveillance|

Study measures vaccine effectiveness against Omicron infection in Ontario

In this not-yet peer reviewed pre-print, led by CITF-funded researcher Dr. Jeff Kwong on behalf of the Canadian Immunization Research Network (CIRN), researchers evaluated the effectiveness of mRNA vaccines against the Omicron variant in Ontario. They found that two doses of COVID-19 vaccines were not protective against Omicron infection. However, more than seven days [...]

2022-01-10T17:57:03-05:00January 10, 2022|General vaccine surveillance|

Global seroprevalence of SARS-CoV-2

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%. In low and middle-income countries, the ratio of seropositive blood [...]

2021-12-21T09:24:43-05:00December 20, 2021|General vaccine surveillance|

Researchers identify features associated with heightened risk of myocarditis/pericarditis following mRNA vaccination

A team that included CITF-funded researcher Dr. Jeffrey Kwong from ICES and Public Health Ontario has found that 70% of cases of myocarditis (inflammation of the heart muscle) and pericarditis (inflammation of the sac holding the heart) following COVID-19 vaccination in Ontario occurred after the second dose. From December 14, 2020, to September 4, [...]

2021-12-14T09:31:42-05:00December 13, 2021|General vaccine surveillance|

Severe adverse effects following immunization with COVID-19 vaccines exceedingly rare: CANVAS-COVID

With more than a million participants enrolled in its study, the Canadian National Vaccine Safety Network (CANVAS-COVID) shows that more than 90% of those who are vaccinated do not experience any side effects other than temporary and localized pain at the injection site. Dr. Julie Bettinger, from the British Columbia Children’s Hospital Research Institute [...]

2021-12-13T14:35:28-05:00December 13, 2021|General vaccine surveillance|

Tracking health events after vaccination: latest results from CANVAS-COVID

The CANVAS-COVID study, funded by the CITF/Vaccine Surveillance Reference Group (VSRG), has collected self-reported information on health events following vaccination in more than one million Canadians so far. The core findings indicate that the incidence of serious side effects, emergency room visits, and hospitalizations following COVID-19 vaccination remain exceedingly rare. Results from the CANVAS-COVID study [...]

2021-09-20T22:27:56-04:00September 21, 2021|General vaccine surveillance|

Poor antibody response to the first dose of the Pfizer-BioNTech vaccine for patients with chronic kidney disease

Patients with chronic kidney disease, including those on dialysis, have been prioritized for vaccination due to increased risk of severe COVID-19 outcomes such as hospitalization and death. In a CITF-funded study now published in JAMA Network Open, several CITF and VSRG-affiliated researchers, including Drs. Michelle Hladunewich and Matthew Oliver report that many dialysis patients [...]

2021-09-16T09:20:28-04:00September 14, 2021|General vaccine surveillance|

Survey offers new insight into which Canadians do not intend to get vaccinated

A national survey has found that at the start of the COVID-19 vaccine rollout, most Canadians planned to get vaccinated, but that intentions were lower among certain demographic groups, including residents of Alberta, Manitoba and Saskatchewan, individuals without a university degree, and racialized Canadians.

2021-09-01T13:29:51-04:00August 31, 2021|General vaccine surveillance, Media Releases|

Tracking health events after vaccination: latest results from CANVAS-COVID

Are you among the over 1 million Canadians asked to complete a survey after receiving the first or second dose of a COVID-19 vaccine? The CANVAS-COVID study, funded by the CITF/VSRG, has been collecting self-reported information on health events following vaccination. The most common health event following vaccination, experienced by 52% of participants enrolled, [...]

2021-08-03T10:23:44-04:00August 3, 2021|General vaccine surveillance|

Vaccine effectiveness against the Gamma variant in a long-term care home in Ontario

An Ontario long-term care home (LTC) suffered a SARS-CoV-2 outbreak attributed to the Gamma variant. Researchers from a CITF-funded study led by Dr. Allison McGeer have published results in Clinical Infectious Diseases revealing that among the residents and staff considered to be part of the outbreak, 77% and 45% respectively, were fully vaccinated. The [...]

2021-07-19T16:24:06-04:00July 20, 2021|General vaccine surveillance|
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