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Table 1 Model parameters, including distributions used in the probabilistic sensitivity analysis

From: The impact of COVID-19 vaccination in prisons in England and Wales: a metapopulation model

Parameter Mean (SE) Distribution Source and notes
R0 5.08 (1.41) log-normal [23]
Percentage reduction in R0 due to shielding and cohorting 40% beta [17]
Vaccine efficacy against infection – first dose 60% (10–70%) beta [24, 25]
Vaccine efficacy against infection – second dose 80% (10–90%) beta
Vaccine efficacy against disease – first dose 60% (50–90%) beta
Vaccine efficacy against disease – second dose 85% (50–95%) beta
Waning of vaccine immunity Vaccine efficacy falls by 19% (95%CI 8%-34%) over six months beta [26]
Duration of natural immunity 16% (95%CI 13–19%) reduction in immunity over one year beta [27]
Staff turnover 8.4% per year (0.1%) beta [28]. In-migration assumed to be equal to out-migration
New people incarcerated 0.60% per day (0.17%) beta [29]. Based on new receptions into local male prisons. In-migration assumed to be equal to out-migration
Number vaccinated per day 20 fixed Assumption based on insights of author from HMPPS (O’Mara)
Community incidence 0.001 per 10,000 people per day (0.0015) fixed [30]
    [31]
Population size of those incarcerated 820 fixed [29]. HMPPS Prison Population Tool. Mean for local male prisons
Staff population size – Staff Group 1 70 fixed [28]. Mean for local male prisons
Staff population size – Staff Group 2 315 fixed [28]. Mean for local male prisons
Age distribution of people who are incarcerated   fixed [29]. HMPPS Prison Population Data Tool, December 2020. Mean for local male prisons
Age distribution of staff   fixed [32]
Contact patterns—Staff Group 1 80% of contacts with other staff in Group 1; 20% with Staff Group 2 fixed Internal HMPPS correspondence
Contact patterns—Staff Group 2 20% of contacts with Staff Group 1; 40% with other staff in Group 2; 40% with people who are incarcerated fixed Internal HMPPS correspondence
Contact patterns—individuals who are incarcerated 40% of contacts with Staff Group 1; 60% of contacts with other people who are incarcerated fixed Internal HMPPS correspondence
Quality-Adjusted Life Year (QALY) loss per symptomatic case 0.008 (4.7 × 10–5) beta [33]
QALY loss per non-fatal hospitalisation 0.018 (0.0018) beta [34]
QALY loss per non-fatal ICU admission 0.154 (0.0304) beta [35]
QALY loss per fatality—staff Age-dependent (SMR = 2, qCM = 0.9, discount rate = 0.35)   [36]
QALY loss per fatality – people who are incarcerated Age-dependent (SMR = 2.3, qCM = 0.9, discount rate = 0.35)   [36, 37]
QALY loss per Adverse Event Following Immunisation (AEFI)—minor 1/365.25 fixed [20]
Frequency of AEFI—minor Age-dependent fixed [38]
QALY loss per AEFI—fatal Age-dependent (SMR = 2, qCM = 0.9, discount rate = 0.35) fixed [36]
Frequency of AEFI—fatal 0.18 × 3/1000000 fixed [39, 40]
Lateral Flow Device (LFD) sensitivity 0.8 (0.125) beta [41]
LFD uptake among prison staff 0.508 (0.107) beta [9]
Vaccine coverage 0.675 (0.148) beta [42]