This is a summary, written by members of the CITF Secretariat, of:

The Ku-gaa-gii pimitizi-win study – Investigating COVID-19 in a cohort of people experiencing homelessness in Toronto. Study updates up to 6 months follow-up October 2023.

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

In this study update presented as an infographic to the CITF, the research team reported the prevalence of SARS-CoV-2 infection at baseline, incidence of first SARS-CoV-2 infections by six months of follow-up, and the rate of vaccination among people experiencing homelessness in Toronto. The study was led by Dr. Stephen Hwang (University of Toronto).

Key findings:

  • 30% of participants had a SARS-CoV-2 infection at the time of their baseline interview (summer 2021).
  • 17% of participants experienced their first SARS-CoV-2 infection within six months after the baseline interview. 75% of infections were unknown to the participant and only discovered through study-administered serologic assay testing or a PCR test.
  • 40% of participants had no history of infection (as of the six-month interview) and 13% were lost to follow-up.
  • Among participants without a history of SARS-CoV-2 infection at baseline, 84% of incident infections occurred after Omicron variants became dominant, after December 2021. Factors positively associated with incident infection were the onset of Omicron and recent immigration to Canada (within 10 years).
  • The vast majority of participants were vaccinated for COVID-19. 28% of participants had four or more doses; 41% had three doses; 19% two doses; 2% one dose; and 10% were unvaccinated.
  • Individual-level factors associated with not receiving vaccination at baseline included younger age, self-identification as Black, self-identification as female, and moderate to low adherence to masking according to public health guidelines.
  • Among people who had not had a vaccine at baseline, the top three reasons included:
    • Concerns about risks and side effects,
    • Lack of confidence in the safety of the vaccines, and
    • Prefer to wait until it seems safe to get the vaccine.

Between June and September 2021, 736 individuals randomly selected from 62 shelters, physical distancing hotels and urban encampments were interviewed about the individual and system-level factors associated with SARS-CoV-2 infection and previous COVID-19 history. They provided saliva and blood biological samples to test for current and past SARS-CoV-2 infection. Participants were interviewed at recruitment (baseline) and re-contacted after three, six, nine, and 12 months for follow-up interviews.