Preparing correctional settings for the next pandemic: a modeling study of COVID-19 outbreaks in two high-income countries

Abstract

Introduction: Correctional facilities are high-priority settings for coordinated public health responses to the COVID-19 pandemic. These facilities are at high risk of disease transmission due to close contacts between people in prison and with the wider community. People in prison are also vulnerable to severe disease given their high burden of co-morbidities.

Methods: We developed a mathematical model to evaluate the effect of various public health interventions, including vaccination, on the mitigation of COVID-19 outbreaks, applying it to prisons in Australia and Canada.

Results: We found that, in the absence of any intervention, an outbreak would occur and infect almost 100% of people in prison within 20 days of the index case. However, the rapid rollout of vaccines with other non-pharmaceutical interventions would almost eliminate the risk of an outbreak.

Discussion: Our study highlights that high vaccination coverage is required for variants with high transmission probability to completely mitigate the outbreak risk in prisons.

Keywords: Australia; COVID-19; Canada; SARS-CoV-2; modeling; prison.

Figure 1

Schematic diagram of COVID-19 disease progression among people in prison and staff.

Figure 2

Interventions incorporated into the model. Each intervention and combined interventions were compared to the no response scenario (status quo). Non-pharmaceutical interventions are in light pink (NPIs) and vaccination is in dark orange.

Figure 3

Number of new infections of COVID-19 among people in prison with the existing prevention strategies at the time of the outbreak [baseline, (A,C)] and comparison with the no intervention strategies [no response scenario (B,D)] in NSW, Australia and Quebec, Canada prisons. The baseline scenario in NSW, Australia was estimated with the delta variant and Quebec, Canada was estimated with the original variant (A) and (B) NSW, Australia (C), and (D) Quebec, Canada.

Figure 4

Change in the number of people in prison infected, hospitalized, recovered and the number who have died throughout a COVID-19 outbreak (delta variant) in the (A) NSW, Australia and (B) Quebec, Canada under the no-response and intervention scenarios. Each intervention is applied separately and in combination. (A) NSW, Australia (B) Quebec, Canada.