SCORE: Serologic Evidence of COVID-19, Social, and Occupational Contacts in Healthcare Workers in a Sample of Long-Term Care and Acute Care Facilities in Southeastern Ontario (SCORE)

Purpose: Healthcare workers (HCW) have been an essential societal resource to face the COVID-19 pandemic. Early in the pandemic, they were at increased risk of contracting SARS-CoV-2 infection. We established a longitudinal cohort of HCW in an acute care hospital and four long-term care facilities in Ontario, Canada to follow the incidence of SARS-CoV-2 infection, the immune response to infection and/or vaccination, and the occupational, household and community factors related to their risk of infection.   Participants Two hundred participants were recruited between November 2020 and July 2021. They completed a baseline survey, monthly surveillance data for 9-12 months, a post-Omicron-wave survey, and provided blood samples for anti-SARS-CoV2 antibody measurements. We collected data on host-related factors (humoral response to vaccines and SARS-CoV-2 infection) and environmental factors ( social contact history, occupational, household and community conditions) to establish the main determinants of risk of SARS-CoV-2 infection.   Findings : Here, we describe the cohort demographics, occupational characteristics, SARS-CoV-2 vaccination status and COVID-19 infection risk during the cohort follow-up.   Analyses: The data from this cohort of HCW allows analyses on 1) the risk factors for SARS-CoV-2 infection, 2) the impact of the Omicron variant on the risk of infection; 3) the relationship between humoral responses and SARS-CoV-2 infection/vaccination and, 4) their relationship of SARS-CoV-2 infection and the community, household and healthcare facility-related exposures. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial NA ### Funding Statement Yes ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: This study was approved by the Queen’s Ethics Board for Research in Humans ethics reference: DEMD-2405-20. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data cannot be shared publicly because this has not been approved by our institution. Data are available once a request is done to any of the investigators and access is approved by the Ethics Committee for researchers who meet the criteria for access to confidential data.