Mark Jit
Mark Jit
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Chair and Professor of the Department of Global and Environmental Health
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Professional overview
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Mark Jit is the inaugural chair and a professor in the Department of Global and Environmental Health. He was formerly head of the Department of Infectious Disease Epidemiology & Dynamics and co-director of the Global Health Economics Centre (GHECO) at the London School of Hygiene & Tropical Medicine (LSHTM). He holds honorary appointments at LSHTM as well as the University of Hong Kong (HKU) and the National University of Singapore (NUS).
Dr. Jit’s research focuses on epidemiological and economic modeling of vaccines to support evidence-based public health decision making. He has published papers covering a range of vaccine-preventable or potentially vaccine-preventable diseases including COVID-19, measles, HPV, pneumococcus, rotavirus, influenza, Group B Streptococcus, dengue, EV71 and RSV as well as methodological papers advancing the ways vaccines are evaluated. This work has influenced many of the major changes to immunization policy in countries around the world. Dr. Jit has served on a number of expert advisory committees in the UK as well as for international organizations such as the World Health Organization. He also organises or contributes to academic and professional courses on vaccine modeling, economics and decision science around the world.
Dr. Jit received his BSc and PhD in Mathematics from University College London, specializing in mathematical biology, and a Master of Public Health degree from King’s College London.
Visit Dr. Jit's Google Scholar's page to learn more about his research portfolio.
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Education
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BSc, Mathematics, University College LondonPhD, Mathematics, University College LondonMPH, Public Health, King's College London
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Honors and awards
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Clarivate Highly Cited Researcher (20222023)Fellow of the Academy of Medical Sciences (2023)Training Fund Award, Health Protection Agency (2007)Andrew Rosen Prize, University College London (1999)Institute of Mathematics and its Applications Award (1998)Departmental Research Studentship, University College London (1998)Student Union Commendation, University College London (1997)Fillon Prize, University College London (1996)Pathfinder Award, University College London (1995)
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Publications
Publications
The cost and cost-effectiveness of novel tuberculosis vaccines in low- and middle-income countries: A modeling study
AbstractPortnoy, A., Clark, R. A., Quaife, M., Weerasuriya, C. K., Mukandavire, C., Bakker, R., Deol, A. K., Malhotra, S., Gebreselassie, N., Zignol, M., Sim, S. Y., Hutubessy, R. C., Baena, I. G., Nishikiori, N., Jit, M., White, R. G., & Menzies, N. A. (n.d.).Publication year
2023Journal title
PLoS MedicineVolume
20Issue
1AbstractBackground Tuberculosis (TB) is preventable and curable but eliminating it has proven challenging. Safe and effective TB vaccines that can rapidly reduce disease burden are essential for achieving TB elimination. We assessed future costs, cost-savings, and cost-effectiveness of introducing novel TB vaccines in low- and middle-income countries (LMICs) for a range of product characteristics and delivery strategies. Methods and findings We developed a system of epidemiological and economic models, calibrated to demographic, epidemiological, and health service data in 105 LMICs. For each country, we assessed the likely future course of TB-related outcomes under several vaccine introduction scenarios, compared to a “no-new-vaccine” counterfactual. Vaccine scenarios considered 2 vaccine product profiles (1 targeted at infants, 1 at adolescents/adults), both assumed to prevent progression to active TB. Key economic inputs were derived from the Global Health Cost Consortium, World Health Organization (WHO) patient cost surveys, and the published literature. We estimated the incremental impact of vaccine introduction for a range of health and economic outcomes. In the base-case, we assumed a vaccine price of $4.60 and used a 1× per-capita gross domestic product (GDP) cost-effectiveness threshold (both varied in sensitivity analyses). Vaccine introduction was estimated to require substantial near-term resources, offset by future cost-savings from averted TB burden. From a health system perspective, adolescent/adult vaccination was cost-effective in 64 of 105 LMICs. From a societal perspective (including productivity gains and averted patient costs), adolescent/adult vaccination was projected to be cost-effective in 73 of 105 LMICs and cost-saving in 58 of 105 LMICs, including 96% of countries with higher TB burden. When considering the monetized value of health gains, we estimated that introduction of an adolescent/adult vaccine could produce $283 to 474 billion in economic benefits by 2050. Limited data availability required assumptions and extrapolations that may omit important country-level heterogeneity in epidemiology and costs. Conclusions TB vaccination would be highly impactful and cost-effective in most LMICs. Further efforts are needed for future development, adoption, and implementation of novel TB vaccines.The effectiveness of pay-it-forward in addressing HPV vaccine delay and increasing uptake among 15–18-year-old adolescent girls compared to user-paid vaccination: a study protocol for a two-arm randomized controlled trial in China
AbstractLi, Y., Qin, C., Qiu, S., He, Y., Pang, L., Xu, X., Yim, V. W. C., Tang, S., Du, H., Gong, W., Yang, F., Tucker, J. D., Tang, W., Wang, Y., Lin, L., Jit, M., Song, W., Li, C., Smith, J., … Wu, D. (n.d.).Publication year
2023Journal title
BMC public healthVolume
23Issue
1AbstractBackground: Human papillomavirus (HPV) vaccination could prevent cervical and other HPV-associated cancers attributable to vaccine-associated HPV types. However, HPV vaccination coverage among women aged 9–18 years old is low in China. Common barriers include poor financial affordability, minimal public engagement, and low confidence in domestically produced HPV vaccines. Pay-it-forward offers an individual a free or subsidized service then an opportunity to voluntarily donate and/or create a postcard message to support future people. This study aims to assess the effectiveness of pay-it-forward as compared to standard-of-care self-paid vaccination to improve HPV vaccine uptake among adolescent girls aged 15–18 years, who are left out in the current pilot free HPV vaccination task force in some parts of China. Methods: This is a two-arm randomized controlled trial in Chengdu, China. Eligible adolescent girls (via caregivers) will be randomly selected and recruited through four community health centers (one in the most developed urban areas, one in higher middle-income and one in lower middle-income suburban areas, and one in the least developed rural areas) using the resident registration list. A total of 320 participants will be randomized into two study arms (user-paid versus pay-it-forward vaccination) in a 1:1 ratio. The intervention assignment will be blinded to recruiters and participants using envelop concealment until the research assistants open the envelop to determine which treatment to deliver to each individual. The primary outcome of the study will be HPV vaccine uptake by administrative data. Secondary outcomes include costs, vaccine hesitancy, and the completion rates of the 3-dose HPV vaccination series. Discussion: This study will investigate an innovative pay-it-forward strategy’s effectiveness and economic costs to improve HPV vaccination among 15–18-year-old adolescent girls. Study findings will have implications for increasing HPV vaccine uptake in places where HPV vaccines are provided for a fee. Trial registration: Chinese Clinical Trial Registry (ChiCTR), ChiCTR2200055542. Registered on 11 January 2022. Graphical Abstract: [Figure not available: see fulltext.].The Full Value of Vaccine Assessments (FVVA): a framework for assessing and communicating the value of vaccines for investment and introduction decision-making
AbstractHutubessy, R., Lauer, J. A., Giersing, B., Sim, S. Y., Jit, M., Kaslow, D., & Botwright, S. (n.d.). In BMC Medicine (1–).Publication year
2023Volume
21Issue
1AbstractBackground: Several economic obstacles can deter the development and use of vaccines. This can lead to limited product options for some diseases, delays in new product development, and inequitable access to vaccines. Although seemingly distinct, these obstacles are actually interrelated and therefore need to be addressed through a single over-arching strategy encompassing all stakeholders. Methods: To help overcome these obstacles, we propose a new approach, the Full Value of Vaccines Assessments (FVVA) framework, to guide the assessment and communication of the value of a vaccine. The FVVA framework is designed to facilitate alignment across key stakeholders and to enhance decision-making around investment in vaccine development, policy-making, procurement, and introduction, particularly for vaccines intended for use in low- and middle-income countries. Results: The FVVA framework has three key elements. First, to enhance assessment, existing value-assessment methods and tools are adapted to include broader benefits of vaccines as well as opportunity costs borne by stakeholders. Second, to improve decision-making, a deliberative process is required to recognize the agency of stakeholders and to ensure country ownership of decision-making and priority setting. Third, the FVVA framework provides a consistent and evidence-based approach that facilitates communication about the full value of vaccines, helping to enhance alignment and coordination across diverse stakeholders. Conclusions: The FVVA framework provides guidance for stakeholders organizing global-level efforts to promote investment in vaccines that are priorities for LMICs. By providing a more holistic view of the benefits of vaccines, its application also has the potential to encourage greater take-up by countries, thereby leading to more sustainable and equitable impacts of vaccines and immunization programmes.The impact of alternative delivery strategies for novel tuberculosis vaccines in low-income and middle-income countries: a modelling study
AbstractClark, R. A., Mukandavire, C., Portnoy, A., Weerasuriya, C. K., Deol, A., Scarponi, D., Iskauskas, A., Bakker, R., Quaife, M., Malhotra, S., Gebreselassie, N., Zignol, M., Hutubessy, R. C., Giersing, B., Jit, M., Harris, R. C., Menzies, N. A., & White, R. G. (n.d.).Publication year
2023Journal title
The Lancet Global HealthVolume
11Issue
4Page(s)
e546-e555AbstractBackground: Tuberculosis is a leading infectious cause of death worldwide. Novel vaccines will be required to reach global targets and reverse setbacks resulting from the COVID-19 pandemic. We estimated the impact of novel tuberculosis vaccines in low-income and middle-income countries (LMICs) in several delivery scenarios. Methods: We calibrated a tuberculosis model to 105 LMICs (accounting for 93% of global incidence). Vaccine scenarios were implemented as the base-case (routine vaccination of those aged 9 years and one-off vaccination for those aged 10 years and older, with country-specific introduction between 2028 and 2047, and 5-year scale-up to target coverage); accelerated scale-up similar to the base-case, but with all countries introducing vaccines in 2025, with instant scale-up; and routine-only (similar to the base-case, but including routine vaccination only). Vaccines were assumed to protect against disease for 10 years, with 50% efficacy. Findings: The base-case scenario would prevent 44·0 million (95% uncertainty range 37·2–51·6) tuberculosis cases and 5·0 million (4·6–5·4) tuberculosis deaths before 2050, compared with equivalent estimates of cases and deaths that would be predicted to occur before 2050 with no new vaccine introduction (the baseline scenario). The accelerated scale-up scenario would prevent 65·5 million (55·6–76·0) cases and 7·9 million (7·3–8·5) deaths before 2050, relative to baseline. The routine-only scenario would prevent 8·8 million (95% uncertainty range 7·6–10·1) cases and 1·1 million (0·9–1·2) deaths before 2050, relative to baseline. Interpretation: Our results suggest novel tuberculosis vaccines could have substantial impact, which will vary depending on delivery strategy. Including a one-off vaccination campaign will be crucial for rapid impact. Accelerated introduction—at a pace similar to that seen for COVID-19 vaccines—would increase the number of lives saved before 2050 by around 60%. Investment is required to support vaccine development, manufacturing, prompt introduction, and scale-up. Funding: WHO (2020/985800-0). Translations: For the French, Spanish, Italian and Dutch translations of the abstract see Supplementary Materials section.The potential cost-effectiveness of next generation influenza vaccines in England and Wales: A modelling analysis
AbstractWaterlow, N. R., Procter, S. R., Van Leeuwen, E., Radhakrishnan, S., Jit, M., & Eggo, R. M. (n.d.).Publication year
2023Journal title
VaccineVolume
41Issue
41Page(s)
6017-6024AbstractNext generation influenza vaccines are in development and have the potential for widespread health and economic benefits. Determining the potential health and economic impact for these vaccines is needed to drive investment in bringing these vaccines to the market, and to inform which groups public health policies on influenza vaccination should target. We used a mathematical modelling approach to estimate the epidemiological impact and cost-effectiveness of next generation influenza vaccines in England and Wales. We used data from an existing fitted model, and evaluated new vaccines with different characteristics ranging from improved vaccines with increased efficacy duration and breadth of protection, to universal vaccines, defined in line with the World Health Organisation (WHO) Preferred Product Characteristics (PPC). We calculated the cost effectiveness of new vaccines in comparison to the current seasonal vaccination programme. We calculated and compared the Incremental Cost-Effectiveness Ratio and Incremental Net Monetary Benefit for each new vaccine type. All analysis was conducted in R. We show that next generation influenza vaccines may result in a 21% to 77% reduction in influenza infections, dependent on vaccine characteristics. Our economic modelling shows that using any of these next generation vaccines at 2019 coverage levels would be highly cost-effective at a willingness to pay threshold of £20,000 for a range of vaccine prices. The vaccine threshold price for the best next generation vaccines in £-2019 is £230 (95%CrI £192 - £269) per dose, but even minimally-improved influenza vaccines could be priced at £18 (95%CrI £16 - £21) per dose and still remain cost-effective. This evaluation demonstrates the promise of next generation influenza vaccines for impact on influenza epidemics, and likely cost-effectiveness profiles. We have provided evidence towards a full value of vaccines assessment which bolsters the investment case for development and roll-out of next-generation influenza vaccines.The potential impact of novel tuberculosis vaccine introduction on economic growth in low- and middle-income countries: A modeling study
AbstractPortnoy, A., Arcand, J. L., Clark, R. A., Weerasuriya, C. K., Mukandavire, C., Bakker, R., Patouillard, E., Gebreselassie, N., Zignol, M., Jit, M., White, R. G., & Menzies, N. A. (n.d.).Publication year
2023Journal title
PLoS MedicineVolume
20Issue
7AbstractBackground Most individuals developing tuberculosis (TB) are working age adults living in low- and middle-income countries (LMICs). The resulting disability and death impact economic productivity and burden health systems. New TB vaccine products may reduce this burden. In this study, we estimated the impact of introducing novel TB vaccines on gross domestic product (GDP) growth in 105 LMICs. Methods and findings We adapted an existing macroeconomic model to simulate country-level GDP trends between 2020 and 2080, comparing scenarios for introduction of hypothetical infant and adolescent/adult vaccines to a no-new-vaccine counterfactual. We parameterized each scenario using estimates of TB-related mortality, morbidity, and healthcare spending from linked epidemiological and costing models. We assumed vaccines would be introduced between 2028 and 2047 and estimated incremental changes in GDP within each country from introduction to 2080, in 2020 US dollars. We tested the robustness of results to alternative analytic specifications. Both vaccine scenarios produced greater cumulative GDP in the modeled countries over the study period, equivalent to $1.6 (95% uncertainty interval: $0.8, 3.0) trillion for the adolescent/adult vaccine and $0.2 ($0.1, 0.4) trillion for the infant vaccine. These GDP gains were substantially lagged relative to the time of vaccine introduction, particularly for the infant vaccine. GDP gains resulting from vaccine introduction were concentrated in countries with higher current TB incidence and earlier vaccine introduction. Results were sensitive to secular trends in GDP growth but relatively robust to other analytic assumptions. Uncertain projections of GDP could alter these projections and affect the conclusions drawn by this analysis. Conclusions Under a range of assumptions, introducing novel TB vaccines would increase economic growth in LMICs.The potential impact of novel tuberculosis vaccines on health equity and financial protection in low-income and middle-income countries
AbstractPortnoy, A., Clark, R. A., Weerasuriya, C. K., Mukandavire, C., Quaife, M., Bakker, R., Garcia Baena, I., Gebreselassie, N., Zignol, M., Jit, M., White, R. G., & Menzies, N. A. (n.d.).Publication year
2023Journal title
BMJ Global HealthVolume
8Issue
7AbstractIntroduction One in two patients developing tuberculosis (TB) in low-income and middle-income countries (LMICs) faces catastrophic household costs. We assessed the potential financial risk protection from introducing novel TB vaccines, and how health and economic benefits would be distributed across income quintiles. Methods We modelled the impact of introducing TB vaccines meeting the World Health Organization preferred product characteristics in 105 LMICs. For each country, we assessed the distribution of health gains, patient costs and household financial vulnerability following introduction of an infant vaccine and separately for an adolescent/adult vaccine, compared with a 'no-new-vaccine' counterfactual. Patient-incurred direct and indirect costs of TB disease exceeding 20% of annual household income were defined as catastrophic. Results Over 2028-2050, the health gains resulting from vaccine introduction were greatest in lower income quintiles, with the poorest 2 quintiles in each country accounting for 56% of total LMIC TB cases averted. Over this period, the infant vaccine was estimated to avert US$5.9 (95% uncertainty interval: US$5.3-6.5) billion in patient-incurred total costs, and the adolescent/adult vaccine was estimated to avert US$38.9 (US$36.6-41.5) billion. Additionally, 3.7 (3.3-4.1) million fewer households were projected to face catastrophic costs with the infant vaccine and 22.9 (21.4-24.5) million with the adolescent/adult vaccine, with 66% of gains accruing in the poorest 2 income quintiles. Conclusion Under a range of assumptions, introducing novel TB vaccines would reduce income-based inequalities in the health and household economic outcomes of TB in LMICs.Transplacental transfer efficiency of maternal antibodies against influenza A(H1N1)pdm09 virus and dynamics of naturally acquired antibodies in Chinese children: a longitudinal, paired mother–neonate cohort study
AbstractLi, M., Wang, W., Chen, J., Zhan, Z., Xu, M., Liu, N., Ren, L., You, L., Zheng, W., Shi, H., Zhao, Z., Huang, C., Chen, X., Zheng, N., Lu, W., Zhou, X., Zhou, J., Liao, Q., Yang, J., … Yu, H. (n.d.).Publication year
2023Journal title
The Lancet MicrobeVolume
4Issue
11Page(s)
e893-e902AbstractBackground: The 2009 pandemic H1N1 influenza A virus (A(H1N1)pdm09 virus) evolves rapidly and has continued to cause severe infections in children since its emergence in 2009. We aimed to characterise the kinetics of maternally and naturally acquired antibodies against historical A(H1N1)pdm09 strains and to assess the extent to which the response to heterologous strains following infection or vaccination affects observed A(H1N1)pdm09 strain-specific antibody titres in a Chinese paediatric population. Methods: In this retrospective study, we used residual serum samples from 528 mother-neonate pairs from a non-interventional, longitudinal cohort study in southern China conducted from Sept 20, 2013, to Aug 24, 2018, from six local hospitals in Anhua County, Hunan Province, China. Mother-neonate pairs were eligible for inclusion if the neonates were born after Sept 20, 2013, and their mothers had resided in the study sites for at least 3 months. We tested samples with a haemagglutination inhibition (HAI) assay to measure antibody levels against three historical A(H1N1)pdm09 strains that were antigenically similar to the strains that circulated during the 2009 pandemic (A/Hunan-Kaifu/SWL4204/2009 [SWL4204/09 strain], A/Hunan-Daxiang/SWL1277/2016 [SWL1277/16 strain], and A/Hunan-Yanfeng/SWL185/2018 [SWL185/18 strain]). We also determined the seroprevalence, geometric mean titres (GMTs), transfer ratio of maternal antibodies, and the dynamics of maternally and naturally acquired antibodies in children, from birth to 3 years of age. Findings: 1066 mother-neonate pairs were enrolled in the original cohort between Sept 20, 2013, and Oct 14, 2015. Of these, 528 pairs (523 mothers, 528 neonates) were selected for the present study. The median age of the mothers was 25 years (IQR 23 to 29). 291 (55%) of 528 children were boys and 237 (45%) were girls, and most children (452 [86%]) were breastfed before the age of 6 months. The GMTs and the seroprevalence for the SWL4204/09 strain were higher than those for the SWL1277/16 and SWL185/18 strains among mothers (GMTs: 10·4 [95% CI 9·8 to 11·1] vs 9·3 [8·7 to 9·8] vs 8·0 [7·5 to 8·4], p<0·0001; seroprevalence: 11·1% [95% CI 8·5 to 14·1] vs 6·9% [4·9 to 9·4] vs 4·6% [3·0 to 6·8], p=0·0003) and among neonates (GMTs: 10·7 [10·0 to 11·5] vs 9·4 [8·8 to 10·0] vs 8·1 [7·6 to 8·6], p<0·0001; seroprevalence: 13·4% [10·7 to 16·7] vs 8·7% [6·5 to 11·5] vs 6·1% [4·2 to 8·5], p=0·0002). Regardless of the A(H1N1)pdm09-specific strain, maternal antibodies could be transferred efficiently via the placenta (mean transfer ratios: 1·10 for SWL4204/09 vs 1·09 for SWL1277/16 vs 1·06 for SWL185/18; p=0·93). The A(H1N1)pdm09 strain-specific antibodies waned below the protective threshold of 1:40 within 2 months after birth. After maternal antibody waning, there were periodic increases and decreases in HAI antibody titres against three A(H1N1)pdm09 strains, and such increases were all significantly associated with a higher immune response to heterologous strains. Vaccination against the SWL4204/09 strain was associated with a poor response to the SWL185/18 strain (β–0·20, 95% CI –0·28 to –0·13; p<0·0001). Interpretation: Our findings suggest low pre-existing immunity against influenza A(H1N1)pdm09 virus among unvaccinated Chinese adult female and paediatric populations. This evidence, together with the rapid decay of maternal antibodies and the observed cross-reactivity among different A(H1N1)pdm09 strains, highlights the importance of accelerating maternal and paediatric influenza vaccination in China. Funding: The Key Program of the National Natural Science Foundation of China. Translation: For the Chinese translation of the abstract see Supplementary Materials section.Using Age-Specific Values for Pediatric HRQoL in Cost-Effectiveness Analysis: Is There a Problem to Be Solved? If So, How?
AbstractDevlin, N. J., Pan, T., Sculpher, M., Jit, M., Stolk, E., Rowen, D., Van Hout, B., & Norman, R. (n.d.).Publication year
2023Journal title
PharmacoEconomicsVolume
41Issue
10Page(s)
1165-1174AbstractValue sets for the EQ-5D-Y-3L published to date appear to have distinctive characteristics compared with value sets for corresponding adult instruments: in many cases, the value for the worst health state is higher and there are fewer values < 0. The aim of this paper is to consider how and why values for child and adult health differ; and what the implications of that are for the use of EQ-5D-Y-3L values in economic evaluations to inform healthcare resource allocation decisions. We posit four potential explanations for the differences in values: (a) The wording of severity labels may mean the worst problems on the EQ-5D-Y-3L are descriptively less severe than those on the EQ-5D-5L; (b) Adults may genuinely consider that children are less badly affected than adults by descriptively similar health issues. That is, for any given health problem, adult respondents in valuation studies consider children’s overall health-related quality of life (HRQoL) on average to be higher than that for adults; (c) Values are being sought by eliciting adults’ stated preferences for HRQoL in another person, rather than in themselves (regardless of whether the ‘other person’ concerned is a child); and (d) The need to elicit preferences for child HRQoL that are anchored at dead = 0 invokes special considerations regarding children’s survival. Existing evidence does not rule out the possibility that (c) and (d) exert an upward bias in values. We consider the implications of that for the interpretation and use of values for pediatric HRQoL. Alternative methods for valuing children’s HRQoL in a manner that is not ‘age specific’ are possible and may help to avoid issues of non-comparability. Use of these methods would place the onus on health technology assessment bodies to reflect any special considerations regarding child quality-adjusted life-year gains.Vaccine Value Profiles
Giersing, B., Karron, R., Tufet-Bayona, M., Trotter, C., Lambach, P., & Jit, M. (n.d.).Publication year
2023Journal title
VaccineVolume
41Page(s)
S1-S2Value profile for respiratory syncytial virus vaccines and monoclonal antibodies
AbstractFleming, J. A., Baral, R., Higgins, D., Khan, S., Kochar, S., Li, Y., Ortiz, J. R., Cherian, T., Feikin, D., Jit, M., Karron, R. A., Limaye, R. J., Marshall, C., Munywoki, P. K., Nair, H., Newhouse, L. C., Nyawanda, B. O., Pecenka, C., Regan, K., … Sparrow, E. (n.d.).Publication year
2023Journal title
VaccineVolume
41Page(s)
S7-S40AbstractRespiratory syncytial virus (RSV) is the predominant cause of acute lower respiratory infection (ALRI) in young children worldwide, yet no licensed RSV vaccine exists to help prevent the millions of illnesses and hospitalizations and tens of thousands of young lives taken each year. Monoclonal antibody (mAb) prophylaxis exists for prevention of RSV in a small subset of very high-risk infants and young children, but the only currently licensed product is impractical, requiring multiple doses and expensive for the low-income settings where the RSV disease burden is greatest. A robust candidate pipeline exists to one day prevent RSV disease in infant and pediatric populations, and it focuses on two promising passive immunization approaches appropriate for low-income contexts: maternal RSV vaccines and long-acting infant mAbs. Licensure of one or more candidates is feasible over the next one to three years and, depending on final product characteristics, current economic models suggest both approaches are likely to be cost-effective. Strong coordination between maternal and child health programs and the Expanded Program on Immunization will be needed for effective, efficient, and equitable delivery of either intervention. This ‘Vaccine Value Profile’ (VVP) for RSV is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships and multi-lateral organizations, and in collaboration with stakeholders from the WHO headquarters. All contributors have extensive expertise on various elements of the RSV VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.What are economic costs and when should they be used in health economic studies?
AbstractTurner, H. C., Sandmann, F. G., Downey, L. E., Orangi, S., Teerawattananon, Y., Vassall, A., & Jit, M. (n.d.).Publication year
2023Journal title
Cost Effectiveness and Resource AllocationVolume
21Issue
1AbstractEconomic analyses of healthcare interventions are an important consideration in evidence-based policymaking. A key component of such analyses is the costs of interventions, for which most are familiar with using budgets and expenditures. However, economic theory states that the true value of a good/service is the value of the next best alternative forgone as a result of using the resource and therefore observed prices or charges do not necessarily reflect the true economic value of resources. To address this, economic costs are a fundamental concept within (health) economics. Crucially, they are intended to reflect the resources’ opportunity costs (the forgone opportunity to use those resources for another purpose) and they are based on the value of the resource's next-best alternative use that has been forgone. This is a broader conceptualization of a resource’s value than its financial cost and recognizes that resources can have a value that may not be fully captured by their market price and that by using a resource it makes it unavailable for productive use elsewhere. Importantly, economic costs are preferred over financial costs for any health economic analyses aimed at informing decisions regarding the optimum allocation of the limited/competing resources available for healthcare (such as health economic evaluations), and they are also important when considering the replicability and sustainability of healthcare interventions. However, despite this, economic costs and the reasons why they are used is an area that can be misunderstood by professionals without an economic background. In this paper, we outline to a broader audience the principles behind economic costs and when and why they should be used within health economic analyses. We highlight that the difference between financial and economic costs and what adjustments are needed within cost calculations will be influenced by the context of the study, the perspective, and the objective.What, how and who: Cost-effectiveness analyses of COVID-19 vaccination to inform key policies in Nigeria
AbstractRuiz, F. J., Torres-Rueda, S., Pearson, C. A., Bergren, E., Okeke, C., Procter, S. R., Madriz-Montero, A., Jit, M., Vassall, A., & Uzochukwu, B. S. (n.d.).Publication year
2023Journal title
PLOS Global Public HealthVolume
3Issue
3AbstractWhile safe and efficacious COVID-19 vaccines have achieved high coverage in high-income settings, roll-out remains slow in sub-Saharan Africa. By April 2022, Nigeria, a country of over 200 million people, had only distributed 34 million doses. To ensure the optimal use of health resources, cost-effectiveness analyses can inform key policy questions in the health technology assessment process. We carried out several cost-effectiveness analyses exploring different COVID-19 vaccination scenarios in Nigeria. In consultation with Nigerian stakeholders, we addressed three key questions: what vaccines to buy, how to deliver them and what age groups to target. We combined an epidemiological model of virus transmission parameterised with Nigeria specific data with a costing model that incorporated local resource use assumptions and prices, both for vaccine delivery as well as costs associated with care and treatment of COVID-19. Scenarios of vaccination were compared with no vaccination. Incremental cost-effectiveness ratios were estimated in terms of costs per disability- adjusted life years averted and compared to commonly used cost-effectiveness ratios. Viral vector vaccines are cost-effective (or cost saving), particularly when targeting older adults. Despite higher efficacy, vaccines employing mRNA technologies are less cost-effective due to high current dose prices. The method of delivery of vaccines makes little difference to the cost-effectiveness of the vaccine. COVID-19 vaccines can be highly effective and cost-effective (as well as cost-saving), although an important determinant of the latter is the price per dose and the age groups prioritised for vaccination. From a health system perspective, viral vector vaccines may represent most cost-effective choices for Nigeria, although this may change with price negotiation.“We usually see a lot of delay in terms of coming for or seeking care”: an expert consultation on COVID testing and care pathways in seven low- and middle-income countries
AbstractBonnet, G., Bimba, J., Chavula, C., Chifamba, H. N., Divala, T., Lescano, A. G., Majam, M., Mbo, D., Suwantika, A. A., Tovar, M. A., Yadav, P., Corbett, E. L., Vassall, A., & Jit, M. (n.d.).Publication year
2023Journal title
BMC health services researchVolume
23Issue
1AbstractBackground: Rapid diagnostic testing may support improved treatment of COVID patients. Understanding COVID testing and care pathways is important for assessing the impact and cost-effectiveness of testing in the real world, yet there is limited information on these pathways in low-and-middle income countries (LMICs). We therefore undertook an expert consultation to better understand testing policies and practices, clinical screening, the profile of patients seeking testing or care, linkage to care after testing, treatment, lessons learnt and expected changes in 2023. Methods: We organized a qualitative consultation with ten experts from seven LMICs (India, Indonesia, Malawi, Nigeria, Peru, South Africa, and Zimbabwe) identified through purposive sampling. We conducted structured interviews during six regional consultations, and undertook a thematic analysis of responses. Results: Participants reported that, after initial efforts to scale-up testing, the policy priority given to COVID testing has declined. Comorbidities putting patients at heightened risk (e.g., diabetes) mainly relied on self-identification. The decision to test following clinical screening was highly context-/location-specific, often dictated by local epidemiology and test availability. When rapid diagnostic tests were available, public sector healthcare providers tended to rely on them for diagnosis (alongside PCR for Asian/Latin American participants), while private sector providers predominantly used polymerase chain reaction (PCR) tests. Positive test results were generally taken at ‘face value’ by clinicians, although negative tests with a high index of suspicion may be confirmed with PCR. However, even with a positive result, patients were not always linked to care in a timely manner because of reluctance to receiving care or delays in returning to care centres upon clinical deterioration. Countries often lacked multiple components of the range of therapeutics advised in WHO guidelines: notably so for oral antivirals designed for high-risk mild patients. Severely ill patients mostly received corticosteroids and, in higher-resourced settings, tocilizumab. Conclusions: Testing does not always prompt enhanced care, due to reluctance on the part of patients and limited therapeutic availability within clinical settings. Any analysis of the impact or cost-effectiveness of testing policies post pandemic needs to either consider investment in optimal treatment pathways or constrain estimates of benefits based on actual practice.A global assessment of the impact of school closure in reducing COVID-19 spread
AbstractWu, J. T., Mei, S., Luo, S., Leung, K., Liu, D., Lv, Q., Liu, J., Li, Y., Prem, K., Jit, M., Weng, J., Feng, T., Zheng, X., & Leung, G. M. (n.d.).Publication year
2022Journal title
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering SciencesVolume
380Issue
2214AbstractProlonged school closure has been adopted worldwide to control COVID-19. Indeed, UN Educational, Scientific and Cultural Organization figures show that two-thirds of an academic year was lost on average worldwide due to COVID-19 school closures. Such pre-emptive implementation was predicated on the premise that school children are a core group for COVID-19 transmission. Using surveillance data from the Chinese cities of Shenzhen and Anqing together, we inferred that compared with the elderly aged 60 and over, children aged 18 and under and adults aged 19-59 were 75% and 32% less susceptible to infection, respectively. Using transmission models parametrized with synthetic contact matrices for 177 jurisdictions around the world, we showed that the lower susceptibility of school children substantially limited the effectiveness of school closure in reducing COVID-19 transmissibility. Our results, together with recent findings that clinical severity of COVID-19 in children is lower, suggest that school closure may not be ideal as a sustained, primary intervention for controlling COVID-19. This article is part of the theme issue 'Data science approach to infectious disease surveillance'.Changes in social contacts in England during the COVID-19 pandemic between March 2020 and March 2021 as measured by the CoMix survey: A repeated cross-sectional study
Failed generating bibliography.AbstractPublication year
2022Journal title
PLoS MedicineVolume
19Issue
3AbstractBackground During: the Coronavirus Disease 2019 (CAU OVID-19): pandemic, the United Kingdom government imposed public health policies in England to reduce social contacts in hopes of curbing virus transmission. We conducted a repeated cross-sectional study to measure contact patterns weekly from March 2020 to March 2021 to estimate the impact of these policies, covering 3 national lockdowns interspersed by periods of less restrictive policies. Methods and findings The repeated cross-sectional survey data were collected using online surveys of representative samples of the UK population by age and gender. Survey participants were recruited by the online market research company Ipsos MORI through internet-based banner and social media ads and email campaigns. The participant data used for this analysis are restricted to those who reported living in England. We calculated the mean daily contacts reported using a (clustered) bootstrap and fitted a censored negative binomial model to estimate age-stratified contact matrices and estimate proportional changes to the basic reproduction number under controlled conditions using the change in contacts as a scaling factor. To put the findings in perspective, we discuss contact rates recorded throughout the year in terms of previously recorded rates from the POLYMOD study social contact study. The survey recorded 101,350 observations from 19,914 participants who reported 466,710 contacts over 53 weeks. We observed changes in social contact patterns in England over time and by participants’ age, personal risk factors, and perception of risk. The mean reported contacts for adults 18 to 59 years old ranged between 2.39 (95% confidence interval [CI] 2.20 to 2.60) contacts and 4.93 (95% CI 4.65 to 5.19) contacts during the study period. The mean contacts for school-age children (5 to 17 years old) ranged from 3.07 (95% CI 2.89 to 3.27) to 15.11 (95% CI 13.87 to 16.41). This demonstrates a sustained decrease in social contacts compared to a mean of 11.08 (95% CI 10.54 to 11.57) contacts per participant in all age groups combined as measured by the POLYMOD social contact study in 2005 to 2006. Contacts measured during periods of lockdowns were lower than in periods of eased social restrictions. The use of face coverings outside the home has remained high since the government mandated use in some settings in July 2020. The main limitations of this analysis are the potential for selection bias, as participants are recruited through internet-based campaigns, and recall bias, in which participants may under- or over-report the number of contacts they have made.Comparative assessment of methods for short-term forecasts of COVID-19 hospital admissions in England at the local level
Failed generating bibliography.AbstractPublication year
2022Journal title
BMC MedicineVolume
20Issue
1AbstractBackground: Forecasting healthcare demand is essential in epidemic settings, both to inform situational awareness and facilitate resource planning. Ideally, forecasts should be robust across time and locations. During the COVID-19 pandemic in England, it is an ongoing concern that demand for hospital care for COVID-19 patients in England will exceed available resources. Methods: We made weekly forecasts of daily COVID-19 hospital admissions for National Health Service (NHS) Trusts in England between August 2020 and April 2021 using three disease-agnostic forecasting models: a mean ensemble of autoregressive time series models, a linear regression model with 7-day-lagged local cases as a predictor, and a scaled convolution of local cases and a delay distribution. We compared their point and probabilistic accuracy to a mean-ensemble of them all and to a simple baseline model of no change from the last day of admissions. We measured predictive performance using the weighted interval score (WIS) and considered how this changed in different scenarios (the length of the predictive horizon, the date on which the forecast was made, and by location), as well as how much admissions forecasts improved when future cases were known. Results: All models outperformed the baseline in the majority of scenarios. Forecasting accuracy varied by forecast date and location, depending on the trajectory of the outbreak, and all individual models had instances where they were the top- or bottom-ranked model. Forecasts produced by the mean-ensemble were both the most accurate and most consistently accurate forecasts amongst all the models considered. Forecasting accuracy was improved when using future observed, rather than forecast, cases, especially at longer forecast horizons. Conclusions: Assuming no change in current admissions is rarely better than including at least a trend. Using confirmed COVID-19 cases as a predictor can improve admissions forecasts in some scenarios, but this is variable and depends on the ability to make consistently good case forecasts. However, ensemble forecasts can make forecasts that make consistently more accurate forecasts across time and locations. Given minimal requirements on data and computation, our admissions forecasting ensemble could be used to anticipate healthcare needs in future epidemic or pandemic settings.Comparing human and model-based forecasts of COVID-19 in Germany and Poland
Failed generating bibliography.AbstractPublication year
2022Journal title
PLoS computational biologyVolume
18Issue
9AbstractForecasts based on epidemiological modelling have played an important role in shaping public policy throughout the COVID-19 pandemic. This modelling combines knowledge about infectious disease dynamics with the subjective opinion of the researcher who develops and refines the model and often also adjusts model outputs. Developing a forecast model is difficult, resource- and time-consuming. It is therefore worth asking what modelling is able to add beyond the subjective opinion of the researcher alone. To investigate this, we analysed different real-time forecasts of cases of and deaths from COVID-19 in Germany and Poland over a 1-4 week horizon submitted to the German and Polish Forecast Hub. We compared crowd forecasts elicited from researchers and volunteers, against a) forecasts from two semi-mechanistic models based on common epidemiological assumptions and b) the ensemble of all other models submitted to the Forecast Hub. We found crowd forecasts, despite being overconfident, to outperform all other methods across all forecast horizons when forecasting cases (weighted interval score relative to the Hub ensemble 2 weeks ahead: 0.89). Forecasts based on computational models performed comparably better when predicting deaths (rel. WIS 1.26), suggesting that epidemiological modelling and human judgement can complement each other in important ways.Considering equity in priority setting using transmission models: Recommendations and data needs
AbstractQuaife, M., Medley, G. F., Jit, M., Drake, T., Asaria, M., Van Baal, P., Baltussen, R., Bollinger, L., Bozzani, F., Brady, O., Broekhuizen, H., Chalkidou, K., Chi, Y. L., Dowdy, D. W., Griffin, S., Haghparast-Bidgoli, H., Hallett, T., Hauck, K., Hollingsworth, T. D., … Gomez, G. B. (n.d.).Publication year
2022Journal title
EpidemicsVolume
41AbstractObjectives: Disease transmission models are used in impact assessment and economic evaluations of infectious disease prevention and treatment strategies, prominently so in the COVID-19 response. These models rarely consider dimensions of equity relating to the differential health burden between individuals and groups. We describe concepts and approaches which are useful when considering equity in the priority setting process, and outline the technical choices concerning model structure, outputs, and data requirements needed to use transmission models in analyses of health equity. Methods: We reviewed the literature on equity concepts and approaches to their application in economic evaluation and undertook a technical consultation on how equity can be incorporated in priority setting for infectious disease control. The technical consultation brought together health economists with an interest in equity-informative economic evaluation, ethicists specialising in public health, mathematical modellers from various disease backgrounds, and representatives of global health funding and technical assistance organisations, to formulate key areas of consensus and recommendations. Results: We provide a series of recommendations for applying the Reference Case for Economic Evaluation in Global Health to infectious disease interventions, comprising guidance on 1) the specification of equity concepts; 2) choice of evaluation framework; 3) model structure; and 4) data needs. We present available conceptual and analytical choices, for example how correlation between different equity- and disease-relevant strata should be considered dependent on available data, and outline how assumptions and data limitations can be reported transparently by noting key factors for consideration. Conclusions: Current developments in economic evaluations in global health provide a wide range of methodologies to incorporate equity into economic evaluations. Those employing infectious disease models need to use these frameworks more in priority setting to accurately represent health inequities. We provide guidance on the technical approaches to support this goal and ultimately, to achieve more equitable health policies.Cost-effectiveness of Respiratory Syncytial Virus Disease Prevention Strategies: Maternal Vaccine Versus Seasonal or Year-Round Monoclonal Antibody Program in Norwegian Children
AbstractLi, X., Bilcke, J., Fernández, L. V., Bont, L., Willem, L., Wisløff, T., Jit, M., & Beutels, P. (n.d.).Publication year
2022Journal title
Journal of Infectious DiseasesVolume
226Page(s)
S95-S101AbstractBackground. Every winter, respiratory syncytial virus (RSV) disease results in thousands of cases in Norwegian children under 5 years of age. We aim to assess the RSV-related economic burden and the cost-effectiveness of upcoming RSV disease prevention strategies including year-round maternal immunization and year-round and seasonal monoclonal antibody (mAb) programs. Methods. Epidemiological and cost data were obtained from Norwegian national registries, while quality-adjusted life-years (QALYs) lost and intervention characteristics were extracted from literature and phase 3 clinical trials. A static model was used and uncertainty was accounted for probabilistically. Value of information was used to assess decision uncertainty. Extensive scenario analyses were conducted, including accounting for long-term consequences of RSV disease. Results. We estimate an annual average of 13 517 RSV cases and 1572 hospitalizations in children under 5, resulting in 79.6 million Norwegian kroner (~€8 million) treatment costs. At €51 per dose for all programs, a 4-month mAb program for neonates born in November to February is the cost-effective strategy for willingness to pay (WTP) values up to €40 000 per QALY gained. For higher WTP values, the longer 6-month mAb program that immunizes neonates from October to March becomes cost-effective. Sensitivity analyses show that year-round maternal immunization can become a cost-effective strategy if priced lower than mAb. Conclusions. Assuming the same pricing, seasonal mAb programs are cost-effective over year-round programs in Norway. The timing and duration of the cost-effective seasonal program are sensitive to the pattern of the RSV season in a country, so continued RSV surveillance data are essential.COVID-19 impact on routine immunisations for vaccine-preventable diseases: Projecting the effect of different routes to recovery
AbstractToor, J., Li, X., Jit, M., Trotter, C. L., Echeverria-Londono, S., Hartner, A. M., Roth, J., Portnoy, A., Abbas, K., Ferguson, N. M., & AM Gaythorpe, K. (n.d.).Publication year
2022Journal title
VaccineVolume
40Issue
31Page(s)
4142-4149AbstractOver the past two decades, vaccination programmes for vaccine-preventable diseases (VPDs) have expanded across low- and middle-income countries (LMICs). However, the rise of COVID-19 resulted in global disruption to routine immunisation activities. Such disruptions could have a detrimental effect on public health, leading to more deaths from VPDs, particularly without mitigation efforts. Hence, as routine immunisation activities resume, it is important to estimate the effectiveness of different approaches for recovery. We apply an impact extrapolation method developed by the Vaccine Impact Modelling Consortium to estimate the impact of COVID-19-related disruptions with different recovery scenarios for ten VPDs across 112 LMICs. We focus on deaths averted due to routine immunisations occurring in the years 2020–2030 and investigate two recovery scenarios relative to a no-COVID-19 scenario. In the recovery scenarios, we assume a 10% COVID-19-related drop in routine immunisation coverage in the year 2020. We then linearly interpolate coverage to the year 2030 to investigate two routes to recovery, whereby the immunization agenda (IA2030) targets are reached by 2030 or fall short by 10%. We estimate that falling short of the IA2030 targets by 10% leads to 11.26% fewer fully vaccinated persons (FVPs) and 11.34% more deaths over the years 2020–2030 relative to the no-COVID-19 scenario, whereas, reaching the IA2030 targets reduces these proportions to 5% fewer FVPs and 5.22% more deaths. The impact of the disruption varies across the VPDs with diseases where coverage expands drastically in future years facing a smaller detrimental effect. Overall, our results show that drops in routine immunisation coverage could result in more deaths due to VPDs. As the impact of COVID-19-related disruptions is dependent on the vaccination coverage that is achieved over the coming years, the continued efforts of building up coverage and addressing gaps in immunity are vital in the road to recovery.Date of introduction and epidemiologic patterns of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Mogadishu, Somalia: Estimates from transmission modelling of satellite-based excess mortality data in 2020
AbstractKoltai, M., Checchi, F., Warsame, A., Bashiir, F., Freemantle, T., Reeve, C., Williams, C., Jit, M., Flasche, S., Davies, N. G., Aweis, A., Ahmed, M., & Dalmar, A. (n.d.).Publication year
2022Journal title
Wellcome Open ResearchVolume
6AbstractBackground: In countries with weak surveillance systems, confirmed coronavirus disease 2019 (COVID-19) deaths are likely to underestimate the pandemic's death toll. Many countries also have incomplete vital registration systems, hampering excess mortality estimation. Here, we fitted a dynamic transmission model to satellite imagery data of cemeteries in Mogadishu, Somalia during 2020 to estimate the date of introduction and other epidemiologic parameters of the early spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in this low-income, crisis-affected setting. Methods: We performed Markov chain Monte Carlo (MCMC) fitting with an age-structured compartmental COVID-19 model to provide median estimates and credible intervals for the date of introduction, the basic reproduction number ( R 0 ) and the effect of non-pharmaceutical interventions (NPIs) up to August 2020. Results: Under the assumption that excess deaths in Mogadishu March-August 2020 were attributable to SARS-CoV-2 infections, we arrived at median estimates of November-December 2019 for the date of introduction and low R 0 estimates (1.4-1.7) reflecting the slow and early rise and long plateau of excess deaths. The date of introduction, the amount of external seeding, the infection fatality rate (IFR) and the effectiveness of NPIs are correlated parameters and not separately identifiable in a narrow range from deaths data. Nevertheless, to obtain introduction dates no earlier than November 2019 a higher population-wide IFR (≥0.7%) had to be assumed than obtained by applying age-specific IFRs from high-income countries to Somalia's age structure. Conclusions: Model fitting of excess mortality data across a range of plausible values of the IFR and the amount of external seeding suggests an early SARS-CoV-2 introduction event may have occurred in Somalia in November-December 2019. Transmissibility in the first epidemic wave was estimated to be lower than in European settings. Alternatively, there was another, unidentified source of sustained excess mortality in Mogadishu from March to August 2020.Determinants of RSV epidemiology following suppression through pandemic contact restrictions
AbstractKoltai, M., Krauer, F., Hodgson, D., Van Leeuwen, E., Treskova-Schwarzbach, M., Jit, M., & Flasche, S. (n.d.).Publication year
2022Journal title
EpidemicsVolume
40AbstractIntroduction: COVID-19 related non-pharmaceutical interventions (NPIs) led to a suppression of RSV circulation in winter 2020/21 in the UK and an off-season resurgence in Summer 2021. We explore how the parameters of RSV epidemiology shape the size and dynamics of post-suppression resurgence and what we can learn about them from the resurgence patterns observed so far. Methods: We developed an age-structured dynamic transmission model of RSV and sampled the parameters governing RSV seasonality, infection susceptibility and post-infection immunity, retaining simulations fitting the UK's pre-pandemic epidemiology by a set of global criteria consistent with likelihood calculations. From Spring 2020 to Summer 2021 we assumed a reduced contact frequency, returning to pre-pandemic levels from Spring 2021. We simulated transmission forwards until 2023 and evaluated the impact of the sampled parameters on the projected trajectories of RSV hospitalisations and compared these to the observed resurgence. Results: Simulations replicated an out-of-season resurgence of RSV in 2021. If unmitigated, paediatric RSV hospitalisation incidence in the 2021/22 season was projected to increase by 30–60% compared to pre-pandemic levels. The increase was larger if infection risk was primarily determined by immunity acquired from previous exposure rather than age-dependent factors, exceeding 90 % and 130 % in 1–2 and 2–5 year old children, respectively. Analysing the simulations replicating the observed early outbreak in 2021 in addition to pre-pandemic RSV data, we found they were characterised by weaker seasonal forcing, stronger age-dependence of infection susceptibility and higher baseline transmissibility. Conclusion: COVID-19 mitigation measures in the UK stopped RSV circulation in the 2020/21 season and generated immunity debt leading to an early off-season RSV epidemic in 2021. A stronger dependence of infection susceptibility on immunity from previous exposure increases the size of the resurgent season. The early onset of the RSV resurgence in 2021, its marginally increased size relative to previous seasons and its decline by January 2022 suggest a stronger dependence of infection susceptibility on age-related factors, as well as a weaker effect of seasonality and a higher baseline transmissibility. The pattern of resurgence has been complicated by contact levels still not back to pre-pandemic levels. Further fitting of RSV resurgence in multiple countries incorporating data on contact patterns will be needed to further narrow down these parameters and to better predict the pathogen's future trajectory, planning for a potential expansion of new immunisation products against RSV in the coming years.Differential health impact of intervention programs for time-varying disease risk: a measles vaccination modeling study
AbstractPortnoy, A., Hsieh, Y. L., Abbas, K., Klepac, P., Santos, H., Brenzel, L., Jit, M., & Ferrari, M. (n.d.).Publication year
2022Journal title
BMC MedicineVolume
20Issue
1AbstractBackground: Dynamic modeling is commonly used to evaluate direct and indirect effects of interventions on infectious disease incidence. The risk of secondary outcomes (e.g., death) attributable to infection may depend on the underlying disease incidence targeted by the intervention. Consequently, the impact of interventions (e.g., the difference in vaccination and no-vaccination scenarios) on secondary outcomes may not be proportional to the reduction in disease incidence. Here, we illustrate the estimation of the impact of vaccination on measles mortality, where case fatality ratios (CFRs) are a function of dynamically changing measles incidence. Methods: We used a previously published model of measles CFR that depends on incidence and vaccine coverage to illustrate the effects of (1) assuming higher CFR in “no-vaccination” scenarios, (2) time-varying CFRs over the past, and (3) time-varying CFRs in future projections on measles impact estimation. We used modeled CFRs in alternative scenarios to estimate measles deaths from 2000 to 2030 in 112 low- and middle-income countries using two models of measles transmission: Pennsylvania State University (PSU) and DynaMICE. We evaluated how different assumptions on future vaccine coverage, measles incidence, and CFR levels in “no-vaccination” scenarios affect the estimation of future deaths averted by measles vaccination. Results: Across 2000–2030, when CFRs are separately estimated for the “no-vaccination” scenario, the measles deaths averted estimated by PSU increased from 85.8% with constant CFRs to 86.8% with CFRs varying 2000–2018 and then held constant or 85.9% with CFRs varying across the entire time period and by DynaMICE changed from 92.0 to 92.4% or 91.9% in the same scenarios, respectively. By aligning both the “vaccination” and “no-vaccination” scenarios with time-variant measles CFR estimates, as opposed to assuming constant CFRs, the number of deaths averted in the vaccination scenarios was larger in historical years and lower in future years. Conclusions: To assess the consequences of health interventions, impact estimates should consider the effect of “no-intervention” scenario assumptions on model parameters, such as measles CFR, in order to project estimated impact for alternative scenarios according to intervention strategies and investment decisions.Dosing interval strategies for two-dose COVID-19 vaccination in 13 middle-income countries of Europe: Health impact modelling and benefit-risk analysis
Failed generating bibliography.AbstractPublication year
2022Journal title
The Lancet Regional Health - EuropeVolume
17AbstractBackground: In settings where the COVID-19 vaccine supply is constrained, extending the intervals between the first and second doses of the COVID-19 vaccine may allow more people receive their first doses earlier. Our aim is to estimate the health impact of COVID-19 vaccination alongside benefit-risk assessment of different dosing intervals in 13 middle-income countries (MICs) of Europe. Methods: We fitted a dynamic transmission model to country-level daily reported COVID-19 mortality in 13 MICs in Europe (Albania, Armenia, Azerbaijan, Belarus, Bosnia and Herzegovina, Bulgaria, Georgia, Republic of Moldova, Russian Federation, Serbia, North Macedonia, Turkey, and Ukraine). A vaccine product with characteristics similar to those of the Oxford/AstraZeneca COVID-19 (AZD1222) vaccine was used in the base case scenario and was complemented by sensitivity analyses around efficacies similar to other COVID-19 vaccines. Both fixed dosing intervals at 4, 8, 12, 16, and 20 weeks and dose-specific intervals that prioritise specific doses for certain age groups were tested. Optimal intervals minimise COVID-19 mortality between March 2021 and December 2022. We incorporated the emergence of variants of concern (VOCs) into the model and conducted a benefit-risk assessment to quantify the tradeoff between health benefits versus adverse events following immunisation. Findings: In all countries modelled, optimal strategies are those that prioritise the first doses among older adults (60+ years) or adults (20+ years), which lead to dosing intervals longer than six months. In comparison, a four-week fixed dosing interval may incur 10.1% [range: 4.3% - 19.0%; n = 13 (countries)] more deaths. The rapid waning of the immunity induced by the first dose (i.e. with means ranging 60-120 days as opposed to 360 days in the base case) resulted in shorter optimal dosing intervals of 8-20 weeks. Benefit-risk ratios were the highest for fixed dosing intervals of 8-12 weeks. Interpretation: We infer that longer dosing intervals of over six months could reduce COVID-19 mortality in MICs of Europe. Certain parameters, such as rapid waning of first-dose induced immunity and increased immune escape through the emergence of VOCs, could significantly shorten the optimal dosing intervals. Funding: World Health Organization.