The Canadian COVID-19 Cohort Study for people working in healthcare [CCCS study data contributed to the CITF Databank]

The objectives were 1) to determine the incidence of symptomatic and asymptomatic infection; 2) study the use and effectiveness of vaccines in HCWs; 3) determine the pattern of immune responses over time via serology; and 4) to measure the mental health impact of working during a pandemic.

Methods

This cohort study enrolled full and part-time HCWs between the ages of 18 and 75 in Alberta, Nova Scotia, Ontario, and Quebec recruited via internal institutional advertisements and social media. A serum or dried blood spot sample was collected at enrolment, 30 days after receipt of each COVID-19 vaccine and each positive PCR or RAT, and every six months thereafter to assess IgG antibody levels. Participants completed questionnaires at enrolment regarding risk factors, vaccinations, past infections.

Questionnaires were every 10 weeks to collect exposure data and as needed to collect vaccination and illness information. Contributed dataset contents: The datasets include 2164 participants who completed baseline questionnaires between June 2020 and March 2022. 87% of participants gave one or more blood samples for SARS-CoV-2 serology over this period. Variables include data in the following areas of information: demographics (age, gender, race-ethnicity and indigeneity, province, household, education, occupation), general health (smokes; asthma, lung disease, or other chronic disease diagnosis; height and weight; flu vaccine), SARS-CoV-2 vaccination, and serology.