Browsing by Author "Rabil, Marie Jeanne"

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    Benefits of integrated screening and vaccination for infection control
    Rabil, Marie Jeanne; Tunc, Sait; Bish, Douglas R.; Bish, Ebru K. (2021-12)
    Importance: Screening and vaccination are essential in the fight against infectious diseases, but need to be integrated and customized based on community and disease characteristics. Objective: To develop effective screening and vaccination strategies, customized for a college campus, to reduce COVID-19 infections, hospitalizations, deaths, and peak hospitalizations. Design, Setting, and Participants: We construct a compartmental model of disease spread for vaccination and routine screening, and study the efficacy of four mitigation strategies (routine screening only, vaccination only, vaccination with partial routine screening, vaccination with full routine screening), and a no-intervention strategy. The study setting is a hypothetical college campus of 5,000 students and 455 faculty members, with 11 undetected, asymptotic SARS-CoV-2 infections at the start of an 80-day semester. For sensitivity analysis, we vary the screening frequency, daily vaccination rate, initial vaccination coverage, and screening and vaccination compliance; and consider three scenarios that represent low/medium/high transmission rates and test efficacy. Model parameters come from publicly available or published sources. Results: With low initial vaccination coverage, even aggressive vaccination and screening result in a high number of infections: 1,024/2,040 (1,532/1,773) with routine daily (every other day) screening of the unvaccinated; 275/895 with daily screening extended to the newly vaccinated in base- and worst-case scenarios, with reproduction numbers 4.75 and 6.75, respectively, representative of COVID-19 Delta variant. With the emergence of the Omicron variant, the reproduction number may increase and/or effective vaccine coverage may decrease if a booster shot is needed to maximize vaccine efficacy. Conclusion: Integrated vaccination and routine screening can allow for a safe opening of a college when initial vaccination coverage is sufficiently high. The interventions need to be customized considering the initial vaccination coverage, estimated compliance, screening and vaccination capacity, disease transmission and adverse outcome rates, and the number of infections/peak hospitalizations the college is willing to tolerate.
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    Benefits of integrated screening and vaccination for infection control
    Rabil, Marie Jeanne; Tunc, Sait; Bish, Douglas R.; Bish, Ebru K. (PLOS, 2022-04-21)
    Importance: Screening and vaccination are essential in the fight against infectious diseases, but need to be integrated and customized based on community and disease characteristics. Objective: To develop effective screening and vaccination strategies, customized for a college campus, to reduce COVID-19 infections, hospitalizations, deaths, and peak hospitalizations. Design, setting, and participants: We construct a compartmental model of disease spread under vaccination and routine screening, and study the efficacy of four mitigation strategies (routine screening only, vaccination only, vaccination with partial or full routine screening), and a no-intervention strategy. The study setting is a hypothetical college campus of 5,000 students and 455 faculty members during the Fall 2021 academic semester, when the Delta variant was the predominant strain. For sensitivity analysis, we vary the screening frequency, daily vaccination rate, initial vaccine coverage, and screening and vaccination compliance; and consider scenarios that represent low/medium/high transmission and test efficacy. Model parameters come from publicly available or published sources. Results: With low initial vaccine coverage (30% in our study), even aggressive vaccination and screening result in a high number of infections: 1,020 to 2,040 (1,530 to 2,480) with routine daily (every other day) screening of the unvaccinated; 280 to 900 with daily screening extended to the newly vaccinated in base- and worst-case scenarios, which respectively consider reproduction numbers of 4.75 and 6.75 for the Delta variant. Conclusion: Integrated vaccination and routine screening can allow for a safe opening of a college when both the vaccine effectiveness and the initial vaccine coverage are sufficiently high. The interventions need to be customized considering the initial vaccine coverage, estimated compliance, screening and vaccination capacity, disease transmission and adverse outcome rates, and the number of infections/peak hospitalizations the college is willing to tolerate.
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    Effective screening strategies for safe opening of universities under Omicron and Delta variants of COVID-19
    Rabil, Marie Jeanne; Tunc, Sait; Bish, Douglas R.; Bish, Ebru K. (Springer Nature, 2022-12-09)
    As new COVID-19 variants emerge, and disease and population characteristics change, screening strategies may also need to change. We develop a decision-making model that can assist a college to determine an optimal screening strategy based on their characteristics and resources, considering COVID-19 infections/hospitalizations/deaths; peak daily hospitalizations; and the tests required. We also use this tool to generate screening guidelines for the safe opening of college campuses. Our compartmental model simulates disease spread on a hypothetical college campus under co-circulating variants with different disease dynamics, considering: (i) the heterogeneity in disease transmission and outcomes for faculty/staff and students based on vaccination status and level of natural immunity; and (ii) variant- and dose-dependent vaccine efficacy. Using the Spring 2022 academic semester as a case study, we study routine screening strategies, and find that screening the faculty/staff less frequently than the students, and/or the boosted and vaccinated less frequently than the unvaccinated, may avert a higher number of infections per test, compared to universal screening of the entire population at a common frequency. We also discuss key policy issues, including the need to revisit the mitigation objective over time, effective strategies that are informed by booster coverage, and if and when screening alone can compensate for low booster coverage.
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    Strategies for Effective Mitigation of Infectious Diseases, with Focus on COVID-19
    Rabil, Marie Jeanne (Virginia Tech, 2024-10-07)
    We present a comprehensive approach to designing and optimizing infectious disease mitigation strategies, with a focus on COVID-19 and closed communities like college campuses. By integrating vaccination and routine screening, we first develop a model to evaluate the efficacy of various strategies in reducing infections, hospitalizations, and deaths on a college campus during the Fall 2021 semester. The findings emphasize the importance of customizing interventions based on factors such as initial vaccine coverage, vaccine effectiveness, compliance rates, and disease transmission dynamics. As COVID-19 variants continue to emerge, we highlight the necessity for adaptive screening strategies that account for the existing variants and differences in transmission and outcomes among population groups, such as faculty/staff, and students, based on their vaccination status and level of natural immunity. Using the Spring 2022 academic semester as a case study, we study various routine screening strategies and find that screening faculty and staff less frequently than students, and/or screening the boosted and vaccinated less frequently than the unvaccinated, may avert a higher number of infections per test compared to universal screening of the entire population at a common frequency. We also discuss key policy issues, including the need to revisit the mitigation objectives over time and determine if and when screening alone can compensate for low booster coverage. In contexts where mandates are not feasible and vaccine hesitancy is prevalent, we explore the role of voluntary vaccination compliance, supported by monetary incentives and routine screening. We introduce an optimization framework that considers the dual role of screening as both a mitigation tool and a non-monetary incentive. This framework necessitates a novel optimization model for incentive design, integrated with a utility-based decision model that accounts for resource constraints and uncertainties in community response to mitigation efforts. We establish structural properties of Pareto sets of strategies and analyze how they adjust with community characteristics, leading to key insights. Our findings offer actionable strategies for diverse communities and underscore the substantial value of tailoring mitigation efforts to community characteristics and incorporating the incentive effect of routine screening. Overall, this research provides actionable insights into the development of targeted and adaptive mitigation strategies that can be applied in diverse community settings, ensuring safe operations and effective disease control amidst evolving epidemiological challenges. The methodologies and insights from our study are poised to inform and guide the design of mitigation strategies in a variety of institution and community settings, contributing significantly to the collective efforts against infectious diseases.