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Shahmanesh M, Chimbindi N, Cowan FM. Person-centered HIV PrEP for cisgender women. Nat Med 2023; 29:2707-2708. [PMID: 37957376 DOI: 10.1038/s41591-023-02618-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Affiliation(s)
- Maryam Shahmanesh
- Africa Health Research Institute (AHRI), Mtubatuba, KwaZulu-Natal, South Africa.
- Institute for Global Health, University College London (UCL), London, UK.
- University of KwaZulu-Natal (UKZN), Durban, South Africa.
| | - Natsayi Chimbindi
- Africa Health Research Institute (AHRI), Mtubatuba, KwaZulu-Natal, South Africa
- Institute for Global Health, University College London (UCL), London, UK
- University of KwaZulu-Natal (UKZN), Durban, South Africa
| | - Frances M Cowan
- Centre for Sexual Health and HIV AIDS Research (CeSHHAR), Harare, Zimbabwe
- Liverpool School of Tropical Medicine (LSTM), Liverpool, UK
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2
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Peebles K, Mittler JE, Goodreau SM, Murphy JT, Reid MC, Abernethy N, Gottlieb GS, Barnabas RV, Herbeck JT. Risk compensation after HIV-1 vaccination may accelerate viral adaptation and reduce cost-effectiveness: a modeling study. Sci Rep 2021; 11:6798. [PMID: 33762616 PMCID: PMC7991033 DOI: 10.1038/s41598-021-85487-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 02/22/2021] [Indexed: 11/09/2022] Open
Abstract
Pathogen populations can evolve in response to selective pressure from vaccine-induced immune responses. For HIV, models predict that viral adaptation, either via strain replacement or selection on de novo mutation, may rapidly reduce the effectiveness of an HIV vaccine. We hypothesized that behavioral risk compensation after vaccination may accelerate the transmission of vaccine resistant strains, increasing the rate of viral adaptation and leading to a more rapid decline in vaccine effectiveness. To test our hypothesis, we modeled: (a) the impact of risk compensation on rates of HIV adaptation via strain replacement in response to a partially effective vaccine; and (b) the combined impact of risk compensation and viral adaptation on vaccine-mediated epidemic control. We used an agent-based epidemic model that was calibrated to HIV-1 trends in South Africa, and includes demographics, sexual network structure and behavior, and within-host disease dynamics. Our model predicts that risk compensation can increase the rate of HIV viral adaptation in response to a vaccine. In combination, risk compensation and viral adaptation can, under certain scenarios, reverse initial declines in prevalence due to vaccination, and result in HIV prevalence at 15 years equal to or greater than prevalence without a vaccine.
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Affiliation(s)
- Kathryn Peebles
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - John E Mittler
- Department of Microbiology, University of Washington, Seattle, WA, USA
| | - Steven M Goodreau
- Center for Studies in Demography and Ecology, University of Washington, Seattle, WA, USA
- Department of Anthropology, University of Washington, Seattle, WA, USA
| | - James T Murphy
- Department of Global Health, University of Washington, Seattle, WA, USA
| | - Molly C Reid
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - Neil Abernethy
- Department of Biomedical Informatics and Medical Education, University of Washington, Seattle, WA, USA
- Department of Health Services, University of Washington, Seattle, WA, USA
| | - Geoffrey S Gottlieb
- Department of Medicine, University of Washington, Seattle, WA, USA
- Center for Emerging and Re-Emerging Infectious Diseases, University of Washington, Seattle, WA, USA
| | - Ruanne V Barnabas
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Department of Global Health, University of Washington, Seattle, WA, USA
- Department of Medicine, University of Washington, Seattle, WA, USA
- International Clinical Research Center, University of Washington, Seattle, WA, USA
| | - Joshua T Herbeck
- Department of Global Health, University of Washington, Seattle, WA, USA.
- International Clinical Research Center, University of Washington, Seattle, WA, USA.
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3
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Macicame I, Bhatt N, Matavele Chissumba R, Eller LA, Viegas E, Araújo K, Nwoga C, Li Q, Milazzo M, Hills NK, Lindan C, Michael NL, Robb ML, Jani I, Polyak CS. HIV prevalence and risk behavior among male and female adults screened for enrolment into a vaccine preparedness study in Maputo, Mozambique. PLoS One 2019; 14:e0221682. [PMID: 31527868 PMCID: PMC6748437 DOI: 10.1371/journal.pone.0221682] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2018] [Accepted: 08/13/2019] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION Mozambique continues to have a significant burden of HIV. Developing strategies to control the HIV epidemic remains a key priority for the Mozambican public health community. The primary aim of this study was to determine HIV prevalence and risk behavior among males and females screened for a HIV vaccine preparedness study in Maputo, Mozambique. METHODS Male and female participants between 18-35 years old were recruited from the general community and from female sex worker (FSW) and lesbian, gay, bisexual, and transgender (LGBT) associations in Maputo. All participants were screened for HIV and a questionnaire was administered to each participant to assess HIV risk behavior. RESULTS A total of 1125 adults were screened for HIV infection, among whom 506 (45%) were male. Among men, 5.7% reported having had sex with men (MSM) and 12% of female participants reported having exchanged sex for money, goods or favors in the past 3 months. The overall HIV prevalence was 10.4%; 10.7% of women, and 10.1% of men were HIV infected; 41.4% of MSM were seropositive. HIV infection was associated with older age (25-35 years old) (OR: 6.13, 95% CI: 3.01, 12.5), MSM (OR: 9.07, 95% CI: 3.85, 21.4), self-perception of being at high-risk for HIV (OR: 3.99, 95% CI: 1.27, 12.5) and self-report of a history of a diagnosis of sexually transmitted infection (OR: 3.75, 95% CI: 1.57, 8.98). CONCLUSION In our cohort, HIV prevalence was much higher among MSM compared to the overall prevalence. Behavioral factors were found to be more associated with HIV prevalence than demographic factors. The study findings demonstrate the critical importance of directing services to minority communities, such as MSM, when prevention strategies are being devised for the general population.
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Affiliation(s)
- Ivalda Macicame
- Instituto Nacional de Saúde, Ministério da Saúde, Mozambique
| | - Nilesh Bhatt
- Instituto Nacional de Saúde, Ministério da Saúde, Mozambique
| | | | - Leigh Anne Eller
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | - Edna Viegas
- Instituto Nacional de Saúde, Ministério da Saúde, Mozambique
| | - Khelvon Araújo
- Instituto Nacional de Saúde, Ministério da Saúde, Mozambique
| | - Chiaka Nwoga
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | - Qun Li
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | - Mark Milazzo
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | - Nancy K. Hills
- University of California San Francisco, San Francisco, California, United States of America
| | - Christina Lindan
- University of California San Francisco, San Francisco, California, United States of America
| | - Nelson L. Michael
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
| | - Merlin L. Robb
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
| | - Ilesh Jani
- Instituto Nacional de Saúde, Ministério da Saúde, Mozambique
| | - Christina S. Polyak
- Military HIV Research Program, Walter Reed Army Institute of Research, Silver Spring, Maryland, United States of America
- Henry Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, United States of America
- * E-mail:
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4
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Adamson B, Garrison L, Barnabas RV, Carlson JJ, Kublin J, Dimitrov D. Competing biomedical HIV prevention strategies: potential cost-effectiveness of HIV vaccines and PrEP in Seattle, WA. J Int AIDS Soc 2019; 22:e25373. [PMID: 31402591 PMCID: PMC6689690 DOI: 10.1002/jia2.25373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Accepted: 07/21/2019] [Indexed: 11/12/2022] Open
Abstract
INTRODUCTION Promising HIV vaccine candidates are steadily progressing through the clinical trial pipeline. Once available, HIV vaccines will be an important complement but also potential competitor to other biomedical prevention tools such as pre-exposure prophylaxis (PrEP). Accordingly, the value of HIV vaccines and the policies for rollout may depend on that interplay and tradeoffs with utilization of existing products. In this economic modelling analysis, we estimate the cost-effectiveness of HIV vaccines considering their potential interaction with PrEP and condom use. METHODS We developed a dynamic model of HIV transmission among the men who have sex with men population (MSM), aged 15-64 years, in Seattle, WA offered PrEP and HIV vaccine over a time horizon of 2025-2045. A healthcare sector perspective with annual discount rate of 3% for costs (2017 USD) and quality-adjusted life years (QALYs) was used. The primary economic endpoint is the incremental cost-effectiveness ratio (ICER) when compared to no HIV vaccine availability. RESULTS HIV vaccines improved population health and increased healthcare costs. Vaccination campaigns achieving 90% coverage of high-risk men and 60% coverage of other men within five years of introduction are projected to avoid 40% of new HIV infections between 2025 and 2045. This increased total healthcare costs by $30 million, with some PrEP costs shifted to HIV vaccine spending. HIV vaccines are estimated to have an ICER of $42,473/QALY, considered cost-effective using a threshold of $150,000/QALY. Results were most sensitive to HIV vaccine efficacy and future changes in the cost of PrEP drugs. Sensitivity analysis found ranges of 30-70% HIV vaccine efficacy remained cost-effective. Results were also sensitive to reductions in condom use among PrEP and vaccine users. CONCLUSIONS Access to an HIV vaccine is desirable as it could increase the overall effectiveness of combination HIV prevention efforts and improve population health. Planning for the rollout and scale-up of HIV vaccines should carefully consider the design of policies that guide interactions between vaccine and PrEP utilization and potential competition.
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Affiliation(s)
- Blythe Adamson
- Department of PharmacyThe Comparative Health Outcomes, Policy, and Economics (CHOICE) InstituteUniversity of WashingtonSeattleWAUSA
- Vaccine and Infectious Diseases DivisionFred Hutchinson Cancer Research CenterSeattleWAUSA
- Flatiron HealthNew YorkNYUSA
| | - Louis Garrison
- Department of PharmacyThe Comparative Health Outcomes, Policy, and Economics (CHOICE) InstituteUniversity of WashingtonSeattleWAUSA
| | - Ruanne V Barnabas
- Vaccine and Infectious Diseases DivisionFred Hutchinson Cancer Research CenterSeattleWAUSA
- Division of Allergy and Infectious DiseasesDepartment of Global HealthUniversity of WashingtonSeattleWAUSA
| | - Josh J Carlson
- Department of PharmacyThe Comparative Health Outcomes, Policy, and Economics (CHOICE) InstituteUniversity of WashingtonSeattleWAUSA
| | - James Kublin
- Division of Allergy and Infectious DiseasesDepartment of Global HealthUniversity of WashingtonSeattleWAUSA
- HIV Vaccine Trials NetworkFred Hutchinson Cancer Research CenterSeattleWAUSA
| | - Dobromir Dimitrov
- Vaccine and Infectious Diseases DivisionFred Hutchinson Cancer Research CenterSeattleWAUSA
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Selinger C, Dimitrov DT, Welkhoff PA, Bershteyn A. The future of a partially effective HIV vaccine: assessing limitations at the population level. Int J Public Health 2019; 64:957-964. [PMID: 30982082 PMCID: PMC6614161 DOI: 10.1007/s00038-019-01234-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 03/02/2019] [Accepted: 03/12/2019] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVES Mathematical models have unanimously predicted that a first-generation HIV vaccine would be useful and cost-effective to roll out, but that its overall impact would be insufficient to reverse the epidemic. Here, we explore what factors contribute most to limiting the impact of such a vaccine. METHODS Ranging from a theoretical ideal to a more realistic regimen, mirroring the one used in the currently ongoing trial in South Africa (HVTN 702), we model a nested hierarchy of vaccine attributes such as speed of scale-up, efficacy, durability, and return rates for booster doses. RESULTS The predominant reasons leading to a substantial loss of vaccine impact on the HIV epidemic are the time required to scale up mass vaccination, limited durability, and waning of efficacy. CONCLUSIONS A first-generation partially effective vaccine would primarily serve as an intermediate milestone, furnishing correlates of immunity and platforms that could serve to accelerate future development of a highly effective, durable, and scalable next-generation vaccine capable of reversing the HIV epidemic.
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Affiliation(s)
- Christian Selinger
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005 USA
| | - Dobromir T. Dimitrov
- Fred Hutchinson Cancer Research Center, 1100 Fairview Ave N, Seattle, WA 98109 USA
| | - Philip A. Welkhoff
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005 USA
| | - Anna Bershteyn
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005 USA
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6
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Selinger C, Bershteyn A, Dimitrov DT, Adamson BJS, Revill P, Hallett TB, Phillips AN, Bekker LG, Rees H, Gray G. Targeting and vaccine durability are key for population-level impact and cost-effectiveness of a pox-protein HIV vaccine regimen in South Africa. Vaccine 2019; 37:2258-2267. [PMID: 30890385 PMCID: PMC6684280 DOI: 10.1016/j.vaccine.2019.02.073] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Revised: 01/31/2019] [Accepted: 02/25/2019] [Indexed: 11/16/2022]
Abstract
BACKGROUND RV144 is to date the only HIV vaccine trial to demonstrate efficacy, albeit rapidly waning over time. The HVTN 702 trial is currently evaluating in South Africa a similar vaccine formulation to that of RV144 for subtype C HIV with additional boosters (pox-protein regimen). Using a detailed stochastic individual-based network model of disease transmission calibrated to the HIV epidemic, we investigate population-level impact and maximum cost of an HIV vaccine to remain cost-effective. METHODS Consistent with the original pox-protein regimen, we model a primary series of five vaccinations meeting the goal of 50% cumulative efficacy 24 months after the first dose and include two-yearly boosters that maintain durable efficacy over 10 years. We simulate vaccination programs in South Africa starting in 2027 under various vaccine targeting and HIV treatment and prevention assumptions. RESULTS Our analysis shows that this partially effective vaccine could prevent, at catch-up vaccination with 60% coverage, up to 941,000 (15.6%) new infections between 2027 and 2047 assuming current trends of antiretroviral treatment. An impact of up to 697,000 (11.5%) infections prevented could be achieved by targeting age cohorts of highest incidence. Economic evaluation indicates that, if treatment scale-up was achieved, vaccination could be cost-effective at a total cost of less than $385 and $62 per 10-year series (cost-effectiveness thresholds of $5,691 and $750). CONCLUSIONS While a partially effective, rapidly waning vaccine could help to prevent HIV infections, it will not eliminate HIV as a public health priority in sub-Saharan Africa. Vaccination is expected to be most effective under targeted delivery to age groups of highest HIV incidence. Awaiting results of trial, the introduction of vaccination should go in parallel with continued innovation in HIV prevention, including studies to determine the costs of delivery and feasibility and further research into products with greater efficacy and durability.
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Affiliation(s)
| | - Anna Bershteyn
- Institute for Disease Modeling, Bellevue, WA, United States
| | - Dobromir T Dimitrov
- Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | - Blythe J S Adamson
- Comparative Health Outcomes, Policy, and Economics (CHOICE) Institute, University of Washington, WA, United States; Vaccine and Infectious Diseases Division, Fred Hutchinson Cancer Research Center, Seattle, WA, United States
| | | | | | | | | | - Helen Rees
- Wits RHI, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Glenda Gray
- Perinatal HIV Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; South African Medical Research Council, Cape Town, South Africa
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7
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Hartnell F, Brown A, Capone S, Kopycinski J, Bliss C, Makvandi-Nejad S, Swadling L, Ghaffari E, Cicconi P, Del Sorbo M, Sbrocchi R, Esposito I, Vassilev V, Marriott P, Gardiner CM, Bannan C, Bergin C, Hoffmann M, Turner B, Nicosia A, Folgori A, Hanke T, Barnes E, Dorrell L. A Novel Vaccine Strategy Employing Serologically Different Chimpanzee Adenoviral Vectors for the Prevention of HIV-1 and HCV Coinfection. Front Immunol 2019; 9:3175. [PMID: 30713538 PMCID: PMC6346592 DOI: 10.3389/fimmu.2018.03175] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/24/2018] [Indexed: 12/21/2022] Open
Abstract
Background: Nearly 3 million people worldwide are coinfected with HIV and HCV. Affordable strategies for prevention are needed. We developed a novel vaccination regimen involving replication-defective and serologically distinct chimpanzee adenovirus (ChAd3, ChAd63) vector priming followed by modified vaccinia Ankara (MVA) boosts, for simultaneous delivery of HCV non-structural (NSmut) and HIV-1 conserved (HIVconsv) region immunogens. Methods: We conducted a phase I trial in which 33 healthy volunteers were sequentially enrolled and vaccinated via the intramuscular route as follows: 9 received ChAd3-NSmut [2.5 × 1010 vp] and MVA-NSmut [2 × 108 pfu] at weeks 0 and 8, respectively; 8 received ChAdV63.HIVconsv [5 × 1010 vp] and MVA.HIVconsv [2 × 108 pfu] at the same interval; 16 were co-primed with ChAd3-NSmut [2.5 × 1010 vp] and ChAdV63.HIVconsv [5 × 1010 vp] followed at week 8 by MVA-NSmut and MVA.HIVconsv [both 1 × 108 pfu]. Immunogenicity was assessed using peptide pools in ex vivo ELISpot and intracellular cytokine assays. Vaccine-induced whole blood transcriptome changes were assessed by microarray analysis. Results: All vaccines were well tolerated and no vaccine-related serious adverse events occurred. Co-administration of the prime-boost vaccine regimens induced high magnitude and broad T cell responses that were similar to those observed following immunization with either regimen alone. Median (interquartile range, IQR) peak responses to NSmut were 3,480 (2,728–4,464) and 3,405 (2,307–7,804) spot-forming cells (SFC)/106 PBMC for single and combined HCV vaccinations, respectively (p = 0.8). Median (IQR) peak responses to HIVconsv were 1,305 (1,095–4,967) and 1,005 (169–2,482) SFC/106 PBMC for single and combined HIV-1 vaccinations, respectively (p = 0.5). Responses were maintained above baseline to 34 weeks post-vaccination. Intracellular cytokine analysis indicated that the responding populations comprised polyfunctional CD4+ and CD8+ T cells. Canonical pathway analysis showed that in the single and combined vaccination groups, pathways associated with antiviral and innate immune responses were enriched for upregulated interferon-stimulated genes 24 h after priming and boosting vaccinations. Conclusions: Serologically distinct adenoviral vectors encoding HCV and HIV-1 immunogens can be safely co-administered without reducing the immunogenicity of either vaccine. This provides a novel strategy for targeting these viruses simultaneously and for other pathogens that affect the same populations. Clinical trial registration:https://clinicaltrials.gov, identifier: NCT02362217
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Affiliation(s)
- Felicity Hartnell
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Anthony Brown
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Jakub Kopycinski
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Carly Bliss
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Leo Swadling
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Emma Ghaffari
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Paola Cicconi
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | | | - Ilaria Esposito
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | | | - Paula Marriott
- Centre for Clinical Vaccinology and Tropical Medicine, Jenner Institute, University of Oxford, Oxford, United Kingdom
| | - Clair M Gardiner
- School of Biochemistry and Immunology, Trinity College, Dublin, Ireland
| | | | | | - Matthias Hoffmann
- Division of Infectious Diseases and Hospital Epidemiology, Kantonsspital St Gallen, St Gallen, Switzerland
| | - Bethany Turner
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Alfredo Nicosia
- Keires AG, Basel, Switzerland.,Department of Molecular Medicine and Medical Biotechnology, University of Naples Federico II, Naples, Italy.,CEINGE-Biotecnologie Avanzate, Naples, Italy
| | | | - Tomáš Hanke
- Jenner Institute Laboratories, University of Oxford, Oxford, United Kingdom.,International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan
| | - Eleanor Barnes
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Oxford NIHR Biomedical Research Centre, Headington, United Kingdom
| | - Lucy Dorrell
- Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Oxford NIHR Biomedical Research Centre, Headington, United Kingdom
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8
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de Montigny S, Adamson BJS, Mâsse BR, Garrison LP, Kublin JG, Gilbert PB, Dimitrov DT. Projected effectiveness and added value of HIV vaccination campaigns in South Africa: A modeling study. Sci Rep 2018; 8:6066. [PMID: 29666455 PMCID: PMC5904131 DOI: 10.1038/s41598-018-24268-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 03/26/2018] [Indexed: 01/14/2023] Open
Abstract
Promising multi-dose HIV vaccine regimens are being tested in trials in South Africa. We estimated the potential epidemiological and economic impact of HIV vaccine campaigns compared to continuous vaccination, assuming that vaccine efficacy is transient and dependent on immune response. We used a dynamic economic mathematical model of HIV transmission calibrated to 2012 epidemiological data to simulate vaccination with anticipated antiretroviral treatment scale-up in South Africa. We estimate that biennial vaccination with a 70% efficacious vaccine reaching 20% of the sexually active population could prevent 480,000-650,000 HIV infections (13.8-15.3% of all infections) over 10 years. Assuming a launch price of $15 per dose, vaccination was found to be cost-effective, with an incremental cost-effectiveness ratio of $13,746 per quality-adjusted life-year as compared to no vaccination. Increasing vaccination coverage to 50% will prevent more infections but is less likely to achieve cost-effectiveness. Campaign vaccination is consistently more effective and costs less than continuous vaccination across scenarios. Results suggest that a partially effective HIV vaccine will have substantial impact on the HIV epidemic in South Africa and offer good value if priced less than $105 for a five-dose series. Vaccination campaigns every two years may offer greater value for money than continuous vaccination reaching the same coverage level.
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Affiliation(s)
- Simon de Montigny
- CHU Sainte-Justine Research Centre, Montreal, Canada
- School of Public Health, University of Montreal, Montreal, Canada
| | - Blythe J S Adamson
- The Comparative Health Outcomes, Policy, and Economics (CHOICE) Institute, School of Pharmacy, University of Washington, Seattle, WA, USA
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, USA
| | - Benoît R Mâsse
- CHU Sainte-Justine Research Centre, Montreal, Canada
- School of Public Health, University of Montreal, Montreal, Canada
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, USA
| | - Louis P Garrison
- The Comparative Health Outcomes, Policy, and Economics (CHOICE) Institute, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - James G Kublin
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, USA
| | - Peter B Gilbert
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, USA
| | - Dobromir T Dimitrov
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, USA.
- Department of Applied Mathematics, University of Washington, Seattle, Washington, USA.
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9
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Bernard CL, Brandeau ML. Structural Sensitivity in HIV Modeling: A Case Study of Vaccination. Infect Dis Model 2017; 2:399-411. [PMID: 29532039 PMCID: PMC5844493 DOI: 10.1016/j.idm.2017.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Accepted: 08/23/2017] [Indexed: 01/04/2023] Open
Abstract
Structural assumptions in infectious disease models, such as the choice of network or compartmental model type or the inclusion of different types of heterogeneity across individuals, might affect model predictions as much as or more than the choice of input parameters. We explore the potential implications of structural assumptions on HIV model predictions and policy conclusions. We illustrate the value of inference robustness assessment through a case study of the effects of a hypothetical HIV vaccine in multiple population subgroups over eight related transmission models, which we sequentially modify to vary over two dimensions: parameter complexity (e.g., the inclusion of age and HCV comorbidity) and contact/simulation complexity (e.g., aggregated compartmental vs. individual/disaggregated compartmental vs. network models). We find that estimates of HIV incidence reductions from network models and individual compartmental models vary, but those differences are overwhelmed by the differences in HIV incidence between such models and the aggregated compartmental models (which aggregate groups of individuals into compartments). Complexities such as age structure appear to buffer the effects of aggregation and increase the threshold of net vaccine effectiveness at which aggregated models begin to overestimate reductions. The differences introduced by parameter complexity in estimated incidence reduction also translate into substantial differences in cost-effectiveness estimates. Parameter complexity does not appear to play a consistent role in differentiating the projections of network models.
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Affiliation(s)
- Cora L. Bernard
- Department of Management Science and Engineering, Stanford University, Stanford, CA, USA
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10
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Adamson BJS, Carlson JJ, Kublin JG, Garrison LP. The Potential Cost-Effectiveness of Pre-Exposure Prophylaxis Combined with HIV Vaccines in the United States. Vaccines (Basel) 2017; 5:vaccines5020013. [PMID: 28538691 PMCID: PMC5492010 DOI: 10.3390/vaccines5020013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Revised: 05/07/2017] [Accepted: 05/19/2017] [Indexed: 11/16/2022] Open
Abstract
This economic evaluation aims to support policy-making on the combined use of pre-exposure prophylaxis (PrEP) with HIV vaccines in development by evaluating the potential cost-effectiveness of implementation that would support the design of clinical trials for the assessment of combined product safety and efficacy. The target study population is a cohort of men who have sex with men (MSM) in the United States. Policy strategies considered include standard HIV prevention, daily oral PrEP, HIV vaccine, and their combination. We constructed a Markov model based on clinical trial data and the published literature. We used a payer perspective, monthly cycle length, a lifetime horizon, and a 3% discount rate. We assumed a price of $500 per HIV vaccine series in the base case. HIV vaccines dominated standard care and PrEP. At current prices, PrEP was not cost-effective alone or in combination. A combination strategy had the greatest health benefit but was not cost-effective (ICER = $463,448/QALY) as compared to vaccination alone. Sensitivity analyses suggest a combination may be valuable for higher-risk men with good adherence. Vaccine durability and PrEP drug prices were key drivers of cost-effectiveness. The results suggest that boosting potential may be key to HIV vaccine value.
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Affiliation(s)
- Blythe J S Adamson
- Pharmaceutical Outcomes Research and Policy, Department of Pharmacy, University of Washington, Seattle, WA 98115, USA.
| | - Josh J Carlson
- Pharmaceutical Outcomes Research and Policy, Department of Pharmacy, University of Washington, Seattle, WA 98115, USA.
| | - James G Kublin
- HIV Vaccine Trials Network, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
- Department of Global Health, University of Washington, Seattle, WA 98115, USA.
| | - Louis P Garrison
- Pharmaceutical Outcomes Research and Policy, Department of Pharmacy, University of Washington, Seattle, WA 98115, USA.
- Department of Global Health, University of Washington, Seattle, WA 98115, USA.
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