Clinical outcomes and cost-effectiveness of COVID-19 vaccination in South Africa

Low- and middle-income countries are implementing COVID-19 vaccination strategies in light of varying vaccine efficacies and costs, supply shortages, and resource constraints. Here, we use a microsimulation model to evaluate clinical outcomes and cost-effectiveness of a COVID-19 vaccination program in South Africa. We varied vaccination coverage, pace, acceptance, effectiveness, and cost as well as epidemic dynamics. Providing vaccines to at least 40% of the population and prioritizing vaccine rollout prevented >9 million infections and >73,000 deaths and reduced costs due to fewer hospitalizations. Model results were most sensitive to assumptions about epidemic growth and prevalence of prior immunity to SARS-CoV-2, though the vaccination program still provided high value and decreased both deaths and health care costs across a wide range of assumptions. Vaccination program implementation factors, including prompt procurement, distribution, and rollout, are likely more influential than characteristics of the vaccine itself in maximizing public health benefits and economic efficiency.

Cost-effectiveness of COVID-19 vaccination in low- and middle-income countries

Despite the advent of safe and highly effective COVID-19 vaccines1-4, pervasive inequities in global distribution persist5. In response, multinational partners have proposed programs to allocate vaccines to low- and middle-income countries (LMICs)6. Yet, there remains a substantial funding gap for such programs7. Further, the optimal vaccine supply is unknown and the cost-effectiveness of investments into global vaccination programs has not been described. We used a validated COVID-19 simulation model8 to project the health benefits and costs of reaching 20%-70% vaccine coverage in 91 LMICs. We show that funding 20% vaccine coverage over one year among 91 LMICs would prevent 294 million infections and 2 million deaths, with 26 million years of life saved at a cost of US$6.4 billion, for an incremental cost effectiveness ratio (ICER) of US$250/year of life saved (YLS). Increasing vaccine coverage up to 50% would prevent millions more infections and save hundreds of thousands of additional lives, with ICERs below US$8,000/YLS. Results were robust to variations in vaccine efficacy and hesitancy, but were more sensitive to assumptions about epidemic pace and vaccination costs. These results support efforts to fund vaccination programs in LMICs and complement arguments about health equity9, economic benefits10, and pandemic control11.

Management Strategies for People Experiencing Sheltered Homelessness during the COVID-19 Pandemic: Clinical Outcomes and Costs

ImportanceApproximately 356,000 people stay in homeless shelters nightly in the US. These individuals are at high risk for COVID-19. ObjectiveTo assess clinical outcomes, costs, and cost-effectiveness of strategies for COVID-19 prevention and management among sheltered homeless adults. DesignWe developed a dynamic microsimulation model of COVID-19. We modeled sheltered homeless adults in Boston, Massachusetts, using cohort characteristics and costs from Boston Health Care for the Homeless Program. Disease progression, transmission, and clinical outcomes data were from published literature and national databases. We examined surging, growing, and slowing epidemics (effective reproduction numbers [Re] 2.6, 1.3, and 0.9). Costs were from a health care sector perspective; time horizon was 4 months. Setting & ParticipantsSimulated cohort of 2,258 adults residing in homeless shelters in Boston. InterventionsWe assessed combinations of daily symptom screening with same-day polymerase chain reaction (PCR) testing of screen-positive individuals, universal PCR testing every 2 weeks, hospital-based COVID-19 care, alternate care sites [ACSs] for mild/moderate COVID-19 management, and moving people from shelters to temporary housing, compared to no intervention. Main OutcomesInfections, hospital-days, costs, and cost-effectiveness. ResultsCompared to no intervention, daily symptom screening with ACSs for those with pending tests or confirmed COVID-19 and mild/moderate disease leads to 37% fewer infections and 46% lower costs when Re=2.6, 75% fewer infections and 72% lower costs when Re=1.3, and 51% fewer infections and 51% lower costs when Re=0.9. Adding universal PCR testing every 2 weeks further decreases infections in all epidemic scenarios, with incremental cost per case prevented of $1,000 (Re=2.6), $27,000 (Re=1.3), and $71,000 (Re=0.9). In all scenarios, moving shelter residents to temporary housing with universal PCR testing every 2 weeks is most effective but substantially more costly than other options. Results are most sensitive to the cost and sensitivity of PCR testing and the efficacy of ACSs in preventing transmission. Conclusions & RelevanceDaily symptom screening and ACSs for sheltered homeless adults will substantially decrease COVID-19 cases and reduce costs compared to no intervention. In a surging epidemic, adding universal PCR testing every 2 weeks further decreases cases at modest incremental cost and should be considered. Key PointsO_ST_ABSQuestionC_ST_ABSWhat are the projected clinical outcomes and costs of strategies for reducing COVID-19 infections among people experiencing sheltered homelessness? FindingsIn this microsimulation modeling study, daily symptom screening with polymerase chain reaction (PCR) testing of screen-positive individuals, paired with non-hospital care site management of people with mild to moderate COVID-19, substantially reduces infections and lowers costs over 4 months compared to no intervention, across a wide range of epidemic scenarios. In a surging epidemic, adding periodic universal PCR testing to symptom screening and non-hospital care site management improves clinical outcomes at modestly increased costs. Periodic universal PCR testing paired with temporary housing further reduces infections but at much higher cost. MeaningDaily symptom screening with PCR testing of screen-positive individuals and use of alternate care sites for COVID-19 management among sheltered homeless people will substantially prevent new cases and reduce costs compared to other strategies.

Clinical Impact, Costs, and Cost-Effectiveness of Expanded SARS-CoV-2 Testing in Massachusetts

BackgroundWe projected the clinical and economic impact of alternative testing strategies on COVID-19 incidence and mortality in Massachusetts using a microsimulation model. MethodsWe compared five testing strategies: 1) PCR-severe-only: PCR testing only patients with severe/critical symptoms; 2) Self-screen: PCR-severe-only plus self-assessment of COVID-19-consistent symptoms with self-isolation if positive; 3) PCR-any-symptom: PCR for any COVID-19-consistent symptoms with self-isolation if positive; 4) PCR-all: PCR-any-symptom and one-time PCR for the entire population; and, 5) PCR-all-repeat: PCR-all with monthly re-testing. We examined effective reproduction numbers (Re, 0.9-2.0) at which policy conclusions would change. We used published data on disease progression and mortality, transmission, PCR sensitivity/specificity (70/100%) and costs. Model-projected outcomes included infections, deaths, tests performed, hospital-days, and costs over 180-days, as well as incremental cost-effectiveness ratios (ICERs, $/quality-adjusted life-year [QALY]). ResultsIn all scenarios, PCR-all-repeat would lead to the best clinical outcomes and PCR-severe-only would lead to the worst; at Re 0.9, PCR-all-repeat vs. PCR-severe-only resulted in a 63% reduction in infections and a 44% reduction in deaths, but required >65-fold more tests/day with 4-fold higher costs. PCR-all-repeat had an ICER <$100,000/QALY only when Re [≥]1.8. At all Re values, PCR-any-symptom was cost-saving compared to other strategies. ConclusionsTesting people with any COVID-19-consistent symptoms would be cost-saving compared to restricting testing to only those with symptoms severe enough to warrant hospital care. Expanding PCR testing to asymptomatic people would decrease infections, deaths, and hospitalizations. Universal screening would be cost-effective when paired with monthly retesting in settings where the COVID-19 pandemic is surging.

Cost-effectiveness of public health strategies for COVID-19 epidemic control in South Africa

BackgroundHealthcare resource constraints in low and middle-income countries necessitate selection of cost-effective public health interventions to address COVID-19. MethodsWe developed a dynamic COVID-19 microsimulation model to evaluate clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal, South Africa. Interventions assessed were Healthcare Testing (HT), where diagnostic testing is performed only for those presenting to healthcare centres; Contact Tracing (CT) in households of cases; Isolation Centres (IC), for cases not requiring hospitalisation; community health worker-led Mass Symptom Screening and diagnostic testing for symptomatic individuals (MS); and Quarantine Centres (QC), for contacts who test negative. Given uncertainties about epidemic dynamics in South Africa, we evaluated two main epidemic scenarios over 360 days, with effective reproduction numbers (Re) of 1{middle dot}5 and 1{middle dot}2. We compared HT, HT+CT, HT+CT+IC, HT+CT+IC+MS, HT+CT+IC+QC, and HT+CT+IC+MS+QC, considering strategies with incremental cost-effectiveness ratio (ICER)