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
Cross-protective efficacy of two human papillomavirus vaccines : A systematic review and meta-analysis
AbstractMalagón, T., Drolet, M., Boily, M. C., Franco, E. L., Jit, M., Brisson, J., & Brisson, M. (n.d.).Publication year
2012Journal title
The Lancet Infectious DiseasesVolume
12Issue
10Page(s)
781-789AbstractBackground: The extent of cross-protection is a key element in the choice of human papillomavirus (HPV) vaccine to use in vaccination programmes. We compared the cross-protective efficacy of the bivalent vaccine (HPV 16 and 18; Cervarix, GlaxoSmithKline Biologicals, Rixensart, Belgium) and quadrivalent vaccine (HPV 6, 11, 16, and 18; Gardasil, Merck, Whitehouse Station, NJ, USA) against non-vaccine type HPVs. Methods: We searched Medline and Embase databases, conference abstracts, and manufacturers' websites for randomised clinical trials assessing the efficacy of bivalent and quadrivalent vaccines against persistent infections (lasting ≥6 months) and cervical intraepithelial neoplasia (CIN) associated with the non-vaccine type HPVs (types 31, 33, 45, 52, and 58). We included studies of participants who were HPV DNA negative before vaccination for all HPV types assessed. We assessed heterogeneity in vaccine efficacy estimates between trials with I2 and χ2 statistics. Findings: We identified two clinical trials (Females United to Unilaterally Reduce Endo/Ectocervical Disease [FUTURE] I and II) of the quadrivalent vaccine and three (Papilloma Trial Against Cancer In Young Adults [PATRICIA], HPV007, and HPV-023) of the bivalent vaccine. Analysis of the most comparable populations (pooled FUTURE I/II data vs PATRICIA) suggested that cross-protective vaccine efficacy estimates against infections and lesions associated with HPV 31, 33, and 45 were usually higher for the bivalent vaccine than the quadrivalent vaccine. Vaccine efficacy in the bivalent trial was higher than it was in the quadrivalent trial against persistent infections with HPV 31 (77·1% [95% CI 67·2 to 84·4] for bivalent vaccine vs 46·2% [15·3 to 66·4] for quadrivalent vaccine; p=0·003) and HPV 45 (79·0% [61·3 to 89·4] vs 7·8% [-67·0 to 49·3]; p=0·0003), and against CIN grade 2 or worse associated with HPV 33 (82·3% [53·4 to 94·7] vs 24·0% [-71·2 to 67·2]; p=0·02) and HPV 45 (100% [41·7 to 100] vs -51·9% [-1717·8 to 82·6]; p=0·04). We noted substantial heterogeneity between vaccine efficacy in bivalent trials against persistent infections with HPV 31 (I2=69%, p=0·04) and HPV 45 (I2=70%, p=0·04), with apparent reductions in cross-protective efficacy with increased follow-up. Interpretation: The bivalent vaccine seems more efficacious against non-vaccine HPV types 31, 33, and 45 than the quadrivalent vaccine, but the differences were not all significant and might be attributable to differences in trial design. Efficacy against persistent infections with types 31 and 45 seemed to decrease in bivalent trials with increased follow-up, suggesting a waning of cross-protection; more data are needed to establish duration of cross-protection. Funding: Public Health Agency of Canada.Economic evaluations of childhood influenza vaccination : A critical review
AbstractNewall, A. T., Jit, M., & Beutels, P. (n.d.).Publication year
2012Journal title
PharmacoEconomicsVolume
30Issue
8Page(s)
647-660AbstractThe potential benefits of influenza vaccination programmes targeted at children have gained increasing attention in recent years.We conducted a literature search of economic evaluations of influenza vaccination in those aged ≤18 years. The search revealed 20 relevant articles, which were reviewed. The studies differed widely in terms of the costs and benefits that were included. The conclusions were generally favourable for vaccination, but often applied a wider perspective (i.e. including productivity losses) than the reference case for economic evaluations used in many countries. Several evaluations estimated outcomes from a single-year epidemiological study, which may limit their validity given the year-to-year variation in influenza transmissibility, virulence, vaccine match and prior immunity. Only one study used a dynamic transmission model able to fully incorporate the indirect herd protection to the wider community.The use of dynamic models offers great scope to capture the population-wide implications of seasonal vaccination efforts, particularly those targeted at children. AdisEnzymes provide demographers with food for thought
AbstractJit, M., & Gerland, P. (n.d.).Publication year
2012Journal title
eLifeVolume
2012Issue
1Abstract~Health and economic impact of the seasonal influenza vaccination programme in England
AbstractBaguelin, M., Jit, M., Miller, E. A., & Edmunds, W. J. (n.d.).Publication year
2012Journal title
VaccineVolume
30Issue
23Page(s)
3459-3462AbstractBackground: The seasonal influenza vaccination programme in England targets individuals over 65. years old and in clinical risk groups. Methods: A model of influenza transmission and disease was fitted to weekly primary care consultations due to influenza in a typical pre-pandemic season (2006/2007). Different scenarios were constructed about influenza severity and how well vaccines match circulating strains to assess the impact and cost-effectiveness of the current vaccination programme. Results: A well-matched vaccine may reduce the incidence of laboratory-confirmed influenza illness from 8.2% (95% range 4.3-13%) to 5.9% (95% range 2.9-9.7%), with 56-73% of this due to indirect protection. The programme is likely to be cost-effective unless both low severity and poor matching is assumed. Conclusion: The current seasonal influenza vaccination programme appears to substantially reduce disease burden and provides good value for money.Mathematical modelling long-term effects of replacing prevnar7 with prevnar13 on invasive pneumococcal diseases in england and wales
AbstractChoi, Y. H., Jit, M., Flasche, S., Gay, N., & Miller, E. A. (n.d.).Publication year
2012Journal title
PloS oneVolume
7Issue
7AbstractIntroduction: England and Wales recently replaced the 7-valent pneumococcal conjugate vaccine (PCV7) with its 13-valent equivalent (PCV13), partly based on projections from mathematical models of the long-term impact of such a switch compared to ceasing pneumococcal conjugate vaccination altogether. Methods: A compartmental deterministic model was used to estimate parameters governing transmission of infection and competition between different groups of pneumococcal serotypes prior to the introduction of PCV13. The best-fitting parameters were used in an individual based model to describe pneumococcal transmission dynamics and effects of various options for the vaccination programme change in England and Wales. A number of scenarios were conducted using (i) different assumptions about the number of invasive pneumococcal disease cases adjusted for the increasing trend in disease incidence prior to PCV7 introduction in England and Wales, and (ii) a range of values representing serotype replacement induced by vaccination of the additional six serotypes in PCV13. Results: Most of the scenarios considered suggest that ceasing pneumococcal conjugate vaccine use would cause an increase in invasive pneumococcal disease incidence, while replacing PCV7 with PCV13 would cause an overall decrease. However, the size of this reduction largely depends on the level of competition induced by the additional serotypes in PCV13. The model estimates that over 20 years of PCV13 vaccination, around 5000-62000 IPD cases could be prevented compared to stopping pneumococcal conjugate vaccination altogether. Conclusion: Despite inevitable uncertainty around serotype replacement effects following introduction of PCV13, the model suggests a reduction in overall invasive pneumococcal disease incidence in all cases. Our results provide useful evidence on the benefits of PCV13 to countries replacing or considering replacing PCV7 with PCV13, as well as data that can be used to evaluate the cost-effectiveness of such a switch.Potential overestimation of HPV vaccine impact due to unmasking of non-vaccine types : Quantification using a multi-type mathematical model
AbstractChoi, Y. H., Chapman, R., Gay, N., & Jit, M. (n.d.).Publication year
2012Journal title
VaccineVolume
30Issue
23Page(s)
3383-3388AbstractIntroduction: Estimates of human papillomavirus (HPV) vaccine impact in clinical trials and modelling studies rely on DNA tests of cytology or biopsy specimens to determine the HPV type responsible for a cervical lesion. DNA of several oncogenic HPV types may be detectable in a specimen. However, only one type may be responsible for a particular cervical lesion. Misattribution of the causal HPV type for a particular abnormality may give rise to an apparent increase in disease due to non-vaccine HPV types following vaccination (" unmasking" ). Methods: To investigate the existence and magnitude of unmasking, we analysed data from residual cytology and biopsy specimens in English women aged 20-64 years old using a stochastic type-specific individual-based model of HPV infection, progression and disease. The model parameters were calibrated to data on the prevalence of HPV DNA and cytological lesion of different grades, and used to assign causal HPV types to cervical lesions. The difference between the prevalence of all disease due to non-vaccine HPV types, and disease due to non-vaccine HPV types in the absence of vaccine HPV types, was then estimated. Results: There could be an apparent maximum increase of 3-10% in long-term cervical cancer incidence due to non-vaccine HPV types following vaccination. Conclusion: Unmasking may be an important phenomenon in HPV post-vaccination epidemiology, in the same way that has been observed following pneumococcal conjugate vaccination.Systematic review of studies evaluating the broader economic impact of vaccination in low and middle income countries
AbstractDeogaonkar, R., Hutubessy, R., Van Der Putten, I., Evers, S., & Jit, M. (n.d.).Publication year
2012Journal title
BMC public healthVolume
12Issue
1AbstractBackground: Most health economic evaluations of childhood vaccination only capture the health and short-term economic benefits. Measuring broader, long-term effects of vaccination on productivity and externalities could provide a more complete picture of the value of vaccines. Method. MEDLINE, EconLit and NHS-EED databases were searched for articles published between January 1990 and July 2011, which captured broader economic benefits of vaccines in low and middle income countries. Studies were included if they captured at least one of the following categories on broader economic impact: outcome-related productivity gains, behaviour-related productivity gains, ecological externalities, equity gains, financial sustainability gains or macroeconomic benefits. Results: Twenty-six relevant studies were found, including observational studies, economic models and contingent valuation studies. Of the identified broader impacts, outcome-related productivity gains and ecological externalities were most commonly accounted for. No studies captured behaviour-related productivity gains or macroeconomic effects. There was some evidence to show that vaccinated children 8-14 years of age benefit from increased cognitive ability. Productivity loss due to morbidity and mortality was generally measured using the human capital approach. When included, herd immunity effects were functions of coverage rates or based on reduction in disease outcomes. External effects of vaccines were observed in terms of equitable health outcomes and contribution towards synergistic and financially sustainable healthcare programs. Conclusion: Despite substantial variation in the methods of measurement and outcomes used, the inclusion of broader economic impact was found to improve the attractiveness of vaccination. Further research is needed on how different tools and techniques can be used in combination to capture the broader impact of vaccination in a way that is consistent with other health economic evaluations. In addition, more country level evidence is needed from low and middle income countries to justify future investments in vaccines and immunization programs. Finally, the proposed broader economic impact framework may contribute towards better communication of the economic arguments surrounding vaccine uptake, leading to investments in immunization by stakeholders outside of the traditional health care sector such as ministries of finance and national treasuries.The cost-effectiveness of a 13-valent pneumococcal conjugate vaccination for infants in England
Abstractvan Hoek, A. J., Choi, Y. H., Trotter, C., Miller, E. A., & Jit, M. (n.d.).Publication year
2012Journal title
VaccineVolume
30Issue
50Page(s)
7205-7213AbstractBackground: In the immunisation schedule in England and Wales, the 7-valent pneumococcal conjugate vaccine (PCV-7) was replaced by the 13-valent vaccine (PCV-13) in April 2010 after having been used since September 2006. The introduction of PCV-7 was informed by a cost effectiveness analysis using an infectious disease model which projected herd immunity and serotype replacement effects based on the post-vaccine experience in the United States at that time. Aim: To investigate the cost effectiveness of the introduction of PCV-13. Method: Invasive disease incidence following vaccination was projected from a dynamic infectious disease model, and combined with serotype specific disease outcomes obtained from a large hospital dataset linked to laboratory confirmation of invasive pneumococcal disease. The economic impact of replacing PCV-7 with PCV-13 was compared to stopping the use of pneumococcal conjugate vaccination altogether. Results: Discontinuing PCV-7 would lead to a projected increase in invasive pneumococcal disease, costs and loss of quality of life compared to the introduction of PCV-13. However under base case assumptions (assuming no impact on non-invasive disease, maximal competition between vaccine and non-vaccine types, time horizon of 30. years, vaccine price of £49.60 a dose. +. £7.50 administration costs and discounting of costs and benefits at 3.5%) the introduction of PCV-13 is only borderline cost effective compared to a scenario of discontinuing of PCV-7. The intervention becomes more cost-effective when projected impact of non-invasive disease is included or the discount factor for benefits is reduced to 1.5%. Conclusion: To our knowledge this is the first evaluation of a transition from PCV-7 to PCV-13 based on a dynamic model. The cost-effectiveness of such a policy change depends on a number of crucial assumptions for which evidence is limited, particularly the impact of PCV-13 on non-invasive disease.7-valent pneumococcal conjugate vaccination in england and wales : Is it still beneficial despite high levels of serotype replacement?
AbstractChoi, Y. H., Jit, M., Gay, N., Andrews, N., Waight, P. A., Melegaro, A., George, R., & Miller, E. A. (n.d.).Publication year
2011Journal title
PloS oneVolume
6Issue
10AbstractBackground: The UK introduced the 7-valent pneumococcal conjugate vaccine (PCV7) into the national vaccination program in September 2006. Previous modelling assumed that the likely impact of PCV7 on invasive pneumococcal disease (IPD) would be similar to the US experience with PCV7. However, recent surveillance data show a more rapid replacement of PCV7 IPD cases by non-PCV7 IPD cases than was seen in the US. Methods and Findings: A previous model of pneumococcal vaccination was re-parameterised using data on vaccine coverage and IPD from England and Wales between 2006 and 2009. Disease incidence was adjusted for the increasing trend in reported IPD cases prior to vaccination. Using this data we estimated that individuals carrying PCV7 serotypes have much higher protection (96%;95% CI 72%-100%) against acquisition of NVT carriage than the 15% previously estimated from US data, which leads to greater replacement. However, even with this level of replacement, the annual number of IPD cases may be 560 (95% CI, -100 to 1230) lower ten years after vaccine introduction compared to what it may have been without vaccination. A particularly marked fall of 39% in children under 15 years by 2015/6 is predicted. Conclusion: Our model suggests that PCV7 vaccination could result in a decrease in overall invasive pneumococcal disease, particularly in children, even in an environment of rapid replacement with non-PCV7 serotypes within 5 years of vaccine introduction at high coverage.Accounting for methodological, structural, and parameter uncertainty in decision-analytic models : A practical guide
AbstractBilcke, J., Beutels, P., Brisson, M., & Jit, M. (n.d.).Publication year
2011Journal title
Medical Decision MakingVolume
31Issue
4Page(s)
675-692AbstractAccounting for uncertainty is now a standard part of decision-analytic modeling and is recommended by many health technology agencies and published guidelines. However, the scope of such analyses is often limited, even though techniques have been developed for presenting the effects of methodological, structural, and parameter uncertainty on model results. To help bring these techniques into mainstream use, the authors present a step-by-step guide that offers an integrated approach to account for different kinds of uncertainty in the same model, along with a checklist for assessing the way in which uncertainty has been incorporated. The guide also addresses special situations such as when a source of uncertainty is difficult to parameterize, resources are limited for an ideal exploration of uncertainty, or evidence to inform the model is not available or not reliable. Methods for identifying the sources of uncertainty that influence results most are also described. Besides guiding analysts, the guide and checklist may be useful to decision makers who need to assess how well uncertainty has been accounted for in a decision-analytic model before using the results to make a decision.Comparative review of three cost-effectiveness models for rotavirus vaccines in national immunization programs; a generic approach applied to various regions in the world
AbstractPostma, M. J., Jit, M., Rozenbaum, M. H., Standaert, B., Tu, H. A., & Hutubessy, R. C. (n.d.).Publication year
2011Journal title
BMC MedicineVolume
9AbstractBackground: This study aims to critically review available cost-effectiveness models for rotavirus vaccination, compare their designs using a standardized approach and compare similarities and differences in cost-effectiveness outcomes using a uniform set of input parameters.Methods: We identified various models used to estimate the cost-effectiveness of rotavirus vaccination. From these, results using a standardized dataset for four regions in the world could be obtained for three specific applications.Results: Despite differences in the approaches and individual constituting elements including costs, QALYs Quality Adjusted Life Years and deaths, cost-effectiveness results of the models were quite similar. Differences between the models on the individual components of cost-effectiveness could be related to some specific features of the respective models. Sensitivity analysis revealed that cost-effectiveness of rotavirus vaccination is highly sensitive to vaccine prices, rotavirus-associated mortality and discount rates, in particular that for QALYs.Conclusions: The comparative approach followed here is helpful in understanding the various models selected and will thus benefit (low-income) countries in designing their own cost-effectiveness analyses using new or adapted existing models. Potential users of the models in low and middle income countries need to consider results from existing studies and reviews. There will be a need for contextualization including the use of country specific data inputs. However, given that the underlying biological and epidemiological mechanisms do not change between countries, users are likely to be able to adapt existing model designs rather than developing completely new approaches. Also, the communication established between the individual researchers involved in the three models is helpful in the further development of these individual models. Therefore, we recommend that this kind of comparative study be extended to other areas of vaccination and even other infectious disease interventions.Comparing bivalent and quadrivalent human papillomavirus vaccines : Economic evaluation based on transmission model
AbstractJit, M., Chapman, R., Hughes, O., & Choi, Y. H. (n.d.).Publication year
2011Journal title
BMJ (Online)Volume
343Issue
7825AbstractObjectives: To compare the effect and cost effectiveness of bivalent and quadrivalent human papillomavirus (HPV) vaccination, taking into account differences in licensure indications, protection against non-vaccine type disease, protection against disease related to HPV types 6 and 11, and reported long term immunogenicity. Design: A model of HPV transmission and disease previously used to inform UK vaccination policy, updated with recent evidence and expanded to include scenarios where the two vaccines differ in duration of protection, cross protection, and end points prevented. Setting: United Kingdom. Population: Males and females aged 12-75 years. Main outcome measure: Incremental cost effectiveness ratios for both vaccines and additional cost per dose for the quadrivalent vaccine to be equally cost effective as the bivalent vaccine. Results: The bivalent vaccine needs to be cheaper than the quadrivalent vaccine to be equally cost effective, mainly because of its lack of protection against anogenital warts. The price difference per dose ranges from a median of £19 (interquartile range £12-£27) to £35 (£27-£44) across scenarios about vaccine duration, cross protection, and end points prevented (assuming one quality adjusted life year (QALY) is valued at £30 000 and both vaccines can prevent all types of HPV related cancers). Conclusions: The quadrivalent vaccine may have an advantage over the bivalent vaccine in reducing healthcare costs and QALYs lost. The bivalent vaccine may have an advantage in preventing death due to cancer. However, considerable uncertainty remains about the differential benefit of the two vaccines.Cost-effectiveness of universal rotavirus vaccination in reducing rotavirus gastroenteritis in Ireland
AbstractTilson, L., Jit, M., Schmitz, S., Walsh, C., Garvey, P., McKeown, P., Barry, M., & Jit, M. (n.d.).Publication year
2011Journal title
VaccineVolume
29Issue
43Page(s)
7463-7473AbstractWe evaluated the cost-effectiveness of universal infant rotavirus (RV) vaccination compared to current standard of care of "no vaccination". Two RV vaccines are currently licensed in Ireland: Rotarix™ and RotaTeq™. A cohort model used in several European countries was adapted using Irish epidemiological, resource utilisation and cost data. The base case model considers the impact of Rotarix vaccination on health-related quality of life of children under five years old from a healthcare payer perspective. Other scenarios explored the use of RotaTeq, impact on one caregiver, on societal costs and on cases that do not seek medical attention. Cost was varied between the vaccine list price (€100/course) in the base case and an assumed tender price (€70/course). One-way and probabilistic sensitivity analyses were conducted. Implementing universal RV vaccination may prevent around 1970 GP visits, 3280 A&E attendances and 2490 hospitalisations. A vaccination programme was estimated to cost approximately €6.54 million per year but €4.65 million of this would be offset by reducing healthcare resource use. The baseline ICER was €112,048/QALY and €72,736/QALY from the healthcare payer and societal perspective, respectively, falling to €68,896 and €43,916/QALY, respectively, if the impact on one caregiver was considered. If the price fell to €70 per course, universal RV vaccination would be cost saving under all scenarios. Results were sensitive to vaccination costs, incidence of RV infection and direct medical costs. Universal RV vaccination would not be cost-effective under base case assumptions. However, it could be cost-effective at a lower vaccine price or from a wider societal perspective.Dedicated outreach service for hard to reach patients with tuberculosis in London : Observational study and economic evaluation
AbstractJit, M., Stagg, H. R., Aldridge, R. W., White, P. J., & Abubakar, I. (n.d.).Publication year
2011Journal title
BMJ (Online)Volume
343Issue
7826AbstractObjective: To assess the cost effectiveness of the Find and Treat service for diagnosing and managing hard to reach individuals with active tuberculosis. Design: Economic evaluation using a discrete, multiple age cohort, compartmental model of treated and untreated cases of active tuberculosis. Setting: London, United Kingdom. Population: Hard to reach individuals with active pulmonary tuberculosis screened or managed by the Find and Treat service (48 mobile screening unit cases, 188 cases referred for case management support, and 180 cases referred for loss to follow-up), and 252 passively presenting controls from London's enhanced tuberculosis surveillance system. Main outcome measures Incremental costs, quality adjusted life years (QALYs), and cost effectiveness ratios for the Find and Treat service. Results The model estimated that, on average, the Find and Treat service identifies 16 and manages 123 active cases of tuberculosis each year in hard to reach groups in London. The service has a net cost of £1.4 million/year and, under conservative assumptions, gains 220 QALYs. The incremental cost effectiveness ratio was £6400-£10 000/QALY gained (about €7300-€11 000 or $10 000-$16 000 in September 2011). The two Find and Treat components were also cost effective, even in unfavourable scenarios (mobile screening unit (for undiagnosed cases), £18 000-£26 000/QALY gained; case management support team, £4100-£6800/QALY gained).Human papillomavirus vaccine introduction in low-income and middle-income countries : Guidance on the use of cost-effectiveness models
AbstractJit, M., Demarteau, N., Elbasha, E., Ginsberg, G., Kim, J., Praditsitthikorn, N., Sinanovic, E., & Hutubessy, R. (n.d.).Publication year
2011Journal title
BMC MedicineVolume
9AbstractBackground: The World Health Organization (WHO) recommends that the cost effectiveness of introducing human papillomavirus (HPV) vaccination is considered before such a strategy is implemented. However, developing countries often lack the technical capacity to perform and interpret results of economic appraisals of vaccines. To provide information about the feasibility of using such models in a developing country setting, we evaluated models of HPV vaccination in terms of their capacity, requirements, limitations and comparability.Methods: A literature review identified six HPV vaccination models suitable for low-income and middle-income country use and representative of the literature in terms of provenance and model structure. Each model was adapted by its developers using standardised data sets representative of two hypothetical developing countries (a low-income country with no screening and a middle-income country with limited screening). Model predictions before and after vaccination of adolescent girls were compared in terms of HPV prevalence and cervical cancer incidence, as was the incremental cost-effectiveness ratio of vaccination under different scenarios.Results: None of the models perfectly reproduced the standardised data set provided to the model developers. However, they agreed that large decreases in type 16/18 HPV prevalence and cervical cancer incidence are likely to occur following vaccination. Apart from the Thai model (in which vaccine and non-vaccine HPV types were combined), vaccine-type HPV prevalence dropped by 75% to 100%, and vaccine-type cervical cancer incidence dropped by 80% to 100% across the models (averaging over age groups). The most influential factors affecting cost effectiveness were the discount rate, duration of vaccine protection, vaccine price and HPV prevalence. Demographic change, access to treatment and data resolution were found to be key issues to consider for models in developing countries.Conclusions: The results indicated the usefulness of considering results from several models and sets of modelling assumptions in decision making. Modelling groups were prepared to share their models and expertise to work with stakeholders in developing countries.Please see related article: http://www.biomedcentral.com/1741-7007/9/55.Modelling borderline and mild dysplasia associated with HPV 6 and 11 infection
AbstractChapman, R., Soldan, K., & Jit, M. (n.d.).Publication year
2011Journal title
VaccineVolume
29Issue
16Page(s)
2881-2886AbstractIntroduction: Low risk HPV types 6/11 are responsible for some low-grade cytological abnormalities. Most economic analyses of HPV vaccination have estimated the additional benefit of HPV 6/11 protection by the quadrivalent vaccine, over the bivalent, based on reduction of genital warts but have not included reduction in repeat smears and colposcopies due to low-grade abnormalities. We investigate the contribution of HPV types 6/11 to abnormal smears and associated costs in England. Methods: The risk of borderline or mild dysplasia due to HPV 6/11 infection was estimated from a study of type-specific HPV DNA in cervical screening specimens collected throughout England. A Markov model representing 10 million women with HPV 6/11 or with no HPV infection from 24 to 64 years was developed to estimate the number of abnormal smears, subsequent repeat smears and colposcopies due to HPV 6/11 associated with borderline or mild dysplasia. Fitting was achieved by varying the force of infection, probability of borderline or mild dysplasia if HPV-uninfected or infected with HPV 6/11 and the duration of infection. Results: The relative risks of borderline or mild dysplasia when infected with HPV 6/11 compared to not being HPV infected were 6.32 (95% credible interval 1.56-25.6) and 17.5 (1.02-300) respectively. Using best fitting parameters we find the costs incurred are between £170 and £195 per abnormal smear due to infection with HPV 6/11. Conclusions: In England, the impact of cytological abnormalities due to HPV 6/11 is relatively small, but not negligible. A vaccine that protects against HPV 6/11 infections could reduce costs associated with borderline and mild dysplasia, and associated colposcopies. These benefits should be considered when formulating immunisation policy, if possible. Smears and colposcopies in those uninfected with HPV far outnumber those in women infected with HPV 6/11.Modelling the epidemiology of infectious diseases for decision analysis : A primer
AbstractJit, M., & Brisson, M. (n.d.).Publication year
2011Journal title
PharmacoEconomicsVolume
29Issue
5Page(s)
371-386AbstractThe number of economic evaluations related to infectious disease topics has increased over the last 2 decades. However, many such evaluations rely on models that do not take into account unique features of infectious diseases that can affect the estimated value of interventions against them. These include their transmissibility from infected to susceptible individuals, the possibility of acquiring natural immunity following recovery from infection and the uncertainties that arise as a result of their complex natural history and epidemiology. Modellers conducting economic evaluations of infectious disease interventions need to know the main features of different types of infectious disease models, the situations in which they should be applied and the effects of model choices on the cost effectiveness of interventions.Prevalence of human papillomavirus antibodies in males and females in England
AbstractDesai, S., Chapman, R., Jit, M., Nichols, T., Borrow, R., Wilding, M., Linford, C., Lowndes, C. M., Nardone, A., Pebody, R., & Soldan, K. (n.d.).Publication year
2011Journal title
Sexually Transmitted DiseasesVolume
38Issue
7Page(s)
622-629AbstractBackground: Most studies of human papillomavirus (HPV) epidemiology have employed DNA testing, which measures current infections. Serum antibodies offer a longer-term marker of infection in individuals who seroconvert and can therefore provide additional information about the exposure of populations to HPV. Methods: Sera from a population-based sample of males and females aged 10 to 49 years, in England, were tested for type-specific HPV antibodies using a multiplexed competitive Luminex assay and previously defined cutoffs of 20, 16, 20, and 24 mMU mL -1 for HPV 6, 11, 16, and 18, respectively. Seropositivity and geometric mean titers of seropositives were analyzed by HPV type, gender, and age. Catalytic models were developed to explore potential effects of antibody waning over time and changing risk of infection by age-cohort. Results: Seroprevalence for HPV 6, 11, 16, and 18 was 16.4%, 5.7%, 14.7%, and 6.3%, respectively, among females and 7.6%, 2.2%, 5.0%, and 2.0%, respectively, among males. Seroprevalence in females was significantly higher than males (P < 0.001 for all types) and showed a decline in older ages that was not seen in males. There was no evidence of declining antibody titers with increasing age. Model results suggest that cohort effects mediated through changes in sexual behavior better explain the observed trend in seroprevalence than waning antibodies over time. Conclusions: Preimmunization HPV seroprevalence in England shows similar trends to reports from other developed countries. We find the lower seroprevalence in older females probably reflects changes in sexual behavior over the last few decades. This study provides baseline data to monitor the impact of the immunization programme.Response to comment on article by Jit et al. "The cost effectiveness of rotavirus vaccination : Comparative analyses for five European countries and transferability in Europe"
AbstractJit, M., Bilcke, J., Mangen, M. J., Salo, H., Melliez, H., Edmunds, W. J., Yazdanpanah, Y., & Beutels, P. (n.d.).Publication year
2011Journal title
VaccineVolume
29Issue
21Page(s)
3732-3733Abstract~The cost-effectiveness of rotavirus vaccination in Armenia
AbstractJit, M., Yuzbashyan, R., Sahakyan, G., Avagyan, T., & Mosina, L. (n.d.).Publication year
2011Journal title
VaccineVolume
29Issue
48Page(s)
9104-9111AbstractThe cost-effectiveness of introducing infant rotavirus vaccination in Armenia in 2012 using Rotarix(R) was evaluated using a multiple birth cohort model. The model considered the cost and health implications of hospitalisations, primary health care consultations and episodes not leading to medical care in children under five years old. Rotavirus vaccination is expected to cost the Ministry of Health $220,000 in 2012, rising to $830,000 in 2016 following termination of GAVI co-financing, then declining to $260,000 in 2025 due to vaccine price maturity. It may reduce health care costs by $34,000 in the first year, rising to $180,000 by 2019. By 2025, vaccination may be close to cost saving to the Ministry of Health if the vaccine purchase price declines as expected. Once coverage has reached high levels, vaccination may prevent 25,000 cases, 3000 primary care consultations, 1000 hospitalisations and 8 deaths per birth cohort vaccinated. The cost per disability-adjusted life year (DALY) saved is estimated to be about $650 from the perspective of the Ministry of Health, $850 including costs accrued to both the Ministry and to GAVI, $820 from a societal perspective excluding indirect costs and $44 from a societal perspective including indirect costs. Since the gross domestic product per capita of Armenia in 2008 was $3800, rotavirus vaccination is likely to be regarded as " very cost-effective" from a WHO standpoint. Vaccination may still be " very cost-effective" if less favourable assumptions are used regarding vaccine price and disease incidence, as long as DALYs are not age-weighted.The impact of genital warts : Loss of quality of life and cost of treatment in eight sexual health clinics in the UK
AbstractWoodhall, S. C., Jit, M., Soldan, K., Kinghorn, G., Gilson, R., Nathan, M., Ross, J. D., Lacey, C. J., & Jit, M. (n.d.).Publication year
2011Journal title
Sexually transmitted infectionsVolume
87Issue
6Page(s)
458-463AbstractObjectives: To estimate the loss of quality of life and cost of treatment associated with genital warts seen in sexual health clinics. Methods: A cross-sectional questionnaire study and case note review of individuals with genital warts, carried out in eight sexual health clinics in England and Northern Ireland. Individuals with genital warts attending the participating clinics were invited to take part in the questionnaire study. 895 participants were recruited. A separate sample of 370 participants who had attended a participating clinic with a first visit for a first or recurrent episode of genital warts between April and June 2007 was included in the case note review. Quality of life was measured using the EQ-5D questionnaire and the cost of an episode of care was derived from the case note review. Results: The weighted mean EQ-5D index score was 0.87 (95% CI 0.85 to 0.89). The weighted mean disutility was 0.056 (95% CI 0.038 to 0.074). The estimated mean loss of quality-adjusted life-years associated with an episode of genital warts was 0.018 (95% CI 0.0079 to 0.031), equivalent to 6.6 days of healthy life lost per episode. The weighted mean cost per episode of care was £94 (95% CI £84 to £104), not including the cost of a sexually transmitted infection screen. Conclusions: Genital warts have a substantial impact on the health service and the individual. This information can be utilised for economic evaluation of human papillomavirus vaccination.The impact of pandemic influenza H1N1 on health-related quality of life : A prospective population-based study
Abstractvan Hoek, A. J., Underwood, A., Jit, M., Miller, E. A., & Edmunds, W. J. (n.d.).Publication year
2011Journal title
PloS oneVolume
6Issue
3AbstractBackground: While the H1N1v influenza pandemic in 2009 was clinically mild, with a low case-fatality rate, the overall disease burden measured in quality-adjusted life years (QALY) lost has not been estimated. Such a measure would allow comparison with other diseases and assessment of the cost-effectiveness of pandemic control measures. Methods and Findings: Cases of H1N1v confirmed by polymerase chain reaction (PCR) and PCR negative cases with similar influenza-like illness (ILI controls) in 7 regions of England were sent two questionnaires, one within a week of symptom onset and one two weeks later, requesting information on duration of illness, work loss and antiviral use together with EQ-5D questionnaires. Results were compared with those for seasonal influenza from a systematic literature review. A total QALY loss for the 2009 pandemic in England was calculated based on the estimated total clinical cases and reported deaths. A total of 655 questionnaires were sent and 296 (45%) returned. Symptoms and average illness duration were similar between confirmed cases and ILI controls (8.8 days and 8.7 days respectively). Days off work were greater for cases than ILI controls (7.3 and 4.9 days respectively, p = 0.003). The quality-adjusted life days lost was 2.92 for confirmed cases and 2.74 for ILI controls, with a reduction in QALY loss after prompt use of antivirals in confirmed cases. The overall QALY loss in the pandemic was estimated at 28,126 QALYs (22,267 discounted) of which 40% was due to deaths (24% with discounting). Conclusion: Given the global public health significance of influenza, it is remarkable that no previous prospective study of the QALY loss of influenza using standardised and well validated methods has been performed. Although the QALY loss was minor for individual patients, the estimated total burden of influenza over the pandemic was substantial when compared to other infectious diseases.What types of contacts are important for the spread of infections? Using contact survey data to explore European mixing patterns
AbstractMelegaro, A., Jit, M., Gay, N., Zagheni, E., & Edmunds, W. J. (n.d.).Publication year
2011Journal title
EpidemicsVolume
3Issue
3-4Page(s)
143-151AbstractKnowledge of the determinants of infectious disease transmission is a public health priority as it allows the design of optimal control strategies for endemic or emerging infections. We analyse a detailed dataset on contact patterns across five European countries and use available serological profiles for varicella and parvovirus B19 infections to identify the types of contact that may be most relevant for transmission. We show that models informed by contact data fit well the observed serological profiles of both infections. We find that intimate types of contacts explain the pattern of acquisition of serological markers by age better than other types of social contacts. We observe similar patterns in each of the countries analysed, suggesting that there are consistent biological mechanisms at work.A brief history of economic evaluation for human papillomavirus vaccination policy
AbstractBeutels, P., & Jit, M. (n.d.).Publication year
2010Journal title
Sexual HealthVolume
7Issue
3Page(s)
352-358AbstractBackground: This commentary discusses key issues for health economic evaluation and modelling, applied to human papillomavirus (HPV) vaccine programs. Methods: We outline some of the specific features of HPV disease and vaccination, and associated policy questions in light of a literature search for economic evaluations on HPV vaccination. Results: We observe that some policy questions could not be reliably addressed by many of the 43 published economic evaluations we found. Despite this, policy making on universal HPV vaccination followed shortly after vaccine licensure in many developed countries, so the role economic evaluation played in informing these decisions (pre-dating 2008) seems to have been fairly limited. For more recent decisions, however, economic evaluation is likely to have been used more widely and more intensively. Conclusions: We expect future cost-effectiveness analyses to be more instrumental in policy making regarding vaccines covering more HPV types, therapeutic HPV vaccines, and novel diagnostic tests for biomarkers of HPV infection and disease integrated with cervical screening programs.An update to " The cost-effectiveness of rotavirus vaccination : Comparative analyses for five European countries and transferability in Europe"
AbstractJit, M., Mangen, M. J., Melliez, H., Yazdanpanah, Y., Bilcke, J., Salo, H., Edmunds, W. J., & Beutels, P. (n.d.).Publication year
2010Journal title
VaccineVolume
28Issue
47Page(s)
7457-7459AbstractA cost-effectiveness analysis of rotavirus vaccination in Belgium, England and Wales, Finland, France and the Netherlands published in 2009 was updated based on recent studies on rotavirus burden of disease and vaccine efficacy. All the qualitative conclusions in the previous study were found to remain valid. Vaccination remains cost-effective in Finland only when using plausible tender prices.