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

Kronfli N, Dussault C, Maheu-Giroux, M, Halavrezos A, Chalifoux S, Park H, Del Balso L, Cheng MP, Cox J. Importance of occupation for SARS-CoV-2 seroprevalence and COVID-19 vaccination among correctional workers in Quebec, Canada: A cross-sectional study. Front. Public Health, 09 November 2022. DOI:

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

A CITF-funded study published in Frontiers in Public Health and led by Dr. Nadine Kronfli (McGill University Health Centre) showed that correctional officers were most likely to have acquired SARS-CoV-2 but least likely to be vaccinated when compared to all other correctional workers, underscoring the importance of addressing both occupational risks and COVID-19 vaccine hesitancy to mitigate future outbreaks in the provincial prisons in Quebec.

Key takeaways

  • In a serosurvey performed between July 14 and November 15, 2021, 105 of 600 (18%) correctional workers in three provincial prisons had a blood test that was positive for SARS-CoV-2 ¬†anti-N antibodies, indicating past infection.
  • Seropositivity was higher among:
    • Correctional officers (adjusted prevalence ratio (aPR)Prevalence Ratio indicates how large is the prevalence of an outcome in one group of individuals (with characteristics/attributes) relative to another group (without the characteristics/attributes). – 1.59, vs. all other occupationsIncludes administration, healthcare provider, kitchen, manager, and other occupations (i.e., probation agent, community workers, janitorial staff, building maintenance, teachers, pastoral, laundry, library, researchers, information technology, and students)) and;
    • Those who perceived their risk of acquiring SARS-CoV-2 in prison to be low (aPR- 1.62 vs. those who said they were somewhat or extremely worried about catching the virus in prison).
  • Based on questionnaires, seventy-six percent (76%) of all correctional workers participating in the study were fully vaccinated. Participants were less likely to be fully vaccinated (two doses or prior infection plus one dose) if they:
    • Were correctional officers (aPR – 0.82 vs. all other occupations).
    • Self-identified as a visible minorityIncludes Black, Latin America, Arab, Asian, and Indigenous (aPR – 0.86, vs. white),
  • Conversely individuals with two or more medical comorbiditiesIncludes hypertension, diabetes, obesity, asthma, chronic lung disease, chronic health disease, chronic kidney disease, liver disease, cancer, chronic blood disorder, chronic neurological disorder, immunocompromised (HIV), immunocompromised (other). (aPR 1.14, vs. none) were more likely to be fully vaccinated against COVID-19.
  • Age, sex, and education were not predictors of COVID-19 vaccine uptake among correctional workers.

A total of 600 correctional workers were enrolled in this study from three provincial prisons in Quebec, representing a participation rate of 57% (600/1,050). Overall, the median age was 43 years; 45% were male, and 75% self-identified as white. 76% had a college-level education or higher. A minority (13%) reported a history of COVID-19, 48% reported at least one comorbidity, and 12% were never vaccinated against COVID-19. More than half (53%) of correctional workers were correction officers and over one-third (38%) reported no concern about getting SARS-CoV-2 in prison (37% among COs).