Mark Jit

Mark Jit
Mark Jit
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Chair and Professor of the Department of Global and Environmental Health

Professional overview

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.

Education

BSc, Mathematics, University College London
PhD, Mathematics, University College London
MPH, Public Health, King's College London

Honors and awards

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)

Publications

Publications

Cost-effectiveness of strategies for preventing paediatric lower respiratory infections associated with respiratory syncytial virus in eight Chinese cities

Liu, D., Leung, K., Jit, M., & Wu, J. T. (n.d.).

Publication year

2021

Journal title

Vaccine

Volume

39

Issue

39

Page(s)

5490-5498
Abstract
Abstract
Background: New monoclonal antibodies (mAbs) and vaccines against RSV with promising efficacy and protection duration are expected to be available in the near future. We evaluated the cost-effectiveness of the administration of maternal immunisation (MI), infant mAb (IA) and paediatric immunisation (PI) as well as their combinations in eight Chinese cities. Methods: We used a static model to estimate the impact of these preventive interventions on reducing the burden of RSV-ALRI in twelve monthly birth cohorts from a societal perspective. In addition to year-round administration, we also considered seasonal administration of MI and IA (i.e., administered only to children born in selected months). The primary outcome was threshold strategy cost (TSC), defined as the maximum costs per child for a strategy to be cost-effective. Results: With a willingness-to-pay threshold of one national GDP per capita per QALY gained for all the cities, TSC of year-round strategies was: (i) US$2.4 (95% CI: 1.9-3.4) to US$14.7 (11.6-21.4) for MI; (ii) US$19.9 (16.9-25.9) to US$144.2 (124.6-184.7) for IA; (iii) US$28.7 (22.0-42.0) to US$201.0 (156.5-298.6) for PI; (iv) US$31.1 (24.0-45.5) to US$220.7 (172.0-327.3) for maternal plus paediatric immunisation (MPI); and (v) US$41.3 (32.6-58.9) to US$306.2 (244.1-441.3) for infant mAb plus paediatric immunisation (AP). In all cities, the top ten seasonal strategies (ranked by TSC) protected infants from 5 or fewer monthly birth cohorts. Conclusions: Administration of these interventions could be cost-effective if they are suitably priced. Suitably-timed seasonal administration could be more cost-effective than their year-round counterpart. Our results can inform the optimal strategy once these preventive interventions are commercially available.

COVID-19 vaccination in Sindh Province, Pakistan: A modelling study of health impact and cost-effectiveness

Pearson, C. A., Bozzani, F., Procter, S. R., Davies, N. G., Huda, M., Jensen, H. T., Keogh-Brown, M., Khalid, M., Sweeney, S., Torres-Rueda, S., Eggo, R. M., Vassall, A., & Jit, M. (n.d.).

Publication year

2021

Journal title

PLoS Medicine

Volume

18

Issue

10
Abstract
Abstract
Background AMUult:ipPlleeaCsoercoonnafirvmiruthsaDtailslheeaasdein2g0le1v9el(sCaOreVreIpDr-e1s9e)ntveadcccoirnreecstlayp: Pear to be safe and efficacious, but only high-income countries have the resources to procure sufficient vaccine doses for most of their eligible populations. The World Health Organization has published guidelines for vaccine prioritisation, but most vaccine impact projections have focused on high-income countries, and few incorporate economic considerations. To address this evidence gap, we projected the health and economic impact of different vaccination scenarios in Sindh Province, Pakistan (population: 48 million). Methods and findings We fitted a compartmental transmission model to COVID-19 cases and deaths in Sindh from 30 April to 15 September 2020. We then projected cases, deaths, and hospitalisation outcomes over 10 years under different vaccine scenarios. Finally, we combined these projections with a detailed economic model to estimate incremental costs (from healthcare and partial societal perspectives), disability-adjusted life years (DALYs), and incremental costeffectiveness ratio (ICER) for each scenario. We project that 1 year of vaccine distribution, at delivery rates consistent with COVAX projections, using an infection-blocking vaccine at $3/dose with 70% efficacy and 2.5-year duration of protection is likely to avert around 0.9 (95% credible interval (CrI): 0.9, 1.0) million cases, 10.1 (95% CrI: 10.1, 10.3) thousand deaths, and 70.1 (95% CrI: 69.9, 70.6) thousand DALYs, with an ICER of $27.9 per DALY averted from the health system perspective. Under a broad range of alternative scenarios, we find that initially prioritising the older (65+) population generally prevents more deaths. However, unprioritised distribution has almost the same cost-effectiveness when considering all outcomes, and both prioritised and unprioritised programmes can be cost-effective for low per-dose costs. High vaccine prices ($10/dose), however, may not be cost-effective, depending on the specifics of vaccine performance, distribution programme, and future pandemic trends. The principal drivers of the health outcomes are the fitted values for the overall transmission scaling parameter and disease natural history parameters from other studies, particularly age-specific probabilities of infection and symptomatic disease, as well as social contact rates. Other parameters are investigated in sensitivity analyses. This study is limited by model approximations, available data, and future uncertainty. Because the model is a single-population compartmental model, detailed impacts of nonpharmaceutical interventions (NPIs) such as household isolation cannot be practically represented or evaluated in combination with vaccine programmes. Similarly, the model cannot consider prioritising groups like healthcare or other essential workers. The model is only fitted to the reported case and death data, which are incomplete and not disaggregated by, e.g., age. Finally, because the future impact and implementation cost of NPIs are uncertain, how these would interact with vaccination remains an open question. Conclusions COVID-19 vaccination can have a considerable health impact and is likely to be cost-effective if more optimistic vaccine scenarios apply. Preventing severe disease is an important contributor to this impact. However, the advantage of prioritising older, high-risk populations is smaller in generally younger populations. This reduction is especially true in populations with more past transmission, and if the vaccine is likely to further impede transmission rather than just disease. Those conditions are typical of many low- and middle-income countries.

COVID-19 vaccine challenges: What have we learned so far and what remains to be done?

Forman, R., Shah, S., Jeurissen, P., Jit, M., & Mossialos, E. (n.d.).

Publication year

2021

Journal title

Health policy

Volume

125

Issue

5

Page(s)

553-567
Abstract
Abstract
Developing and distributing a safe and effective SARS-CoV-2 (COVID-19) vaccine has garnered immense global interest. Less than a year after COVID-19 was declared a pandemic, several vaccine candidates had received emergency use authorization across a range of countries. Despite this scientific breakthrough, the journey from vaccine discovery to global herd immunity against COVID-19 continues to present significant policy challenges that require a collaborative, global response. We offer a framework for understanding remaining and new policy challenges for successful global vaccine campaigns against COVID-19 as well as potential solutions to address them. Decision-makers must be aware of these challenges and strategize solutions that can be implemented at scale. These include challenges around maintaining R&D incentives, running clinical trials, authorizations, post-market surveillance, manufacturing and supply, global dissemination, allocation, uptake, and clinical system adaption. Alongside these challenges, financial and ethical concerns must also be addressed.

Divergent vaccination policies could fuel mistrust and hesitancy

Forman, R., Jit, M., & Mossialos, E. (n.d.). In The Lancet (1–).

Publication year

2021

Volume

397

Issue

10292

Page(s)

2333

Effect of evidence updates on key determinants of measles vaccination impact: a DynaMICE modelling study in ten high-burden countries

Fu, H., Abbas, K., Klepac, P., Van Zandvoort, K., Tanvir, H., Portnoy, A., & Jit, M. (n.d.).

Publication year

2021

Journal title

BMC Medicine

Volume

19

Issue

1
Abstract
Abstract
Background: Model-based estimates of measles burden and the impact of measles-containing vaccine (MCV) are crucial for global health priority setting. Recently, evidence from systematic reviews and database analyses have improved our understanding of key determinants of MCV impact. We explore how representations of these determinants affect model-based estimation of vaccination impact in ten countries with the highest measles burden. Methods: Using Dynamic Measles Immunisation Calculation Engine (DynaMICE), we modelled the effect of evidence updates for five determinants of MCV impact: case-fatality risk, contact patterns, age-dependent vaccine efficacy, the delivery of supplementary immunisation activities (SIAs) to zero-dose children, and the basic reproduction number. We assessed the incremental vaccination impact of the first (MCV1) and second (MCV2) doses of routine immunisation and SIAs, using metrics of total vaccine-averted cases, deaths, and disability-adjusted life years (DALYs) over 2000–2050. We also conducted a scenario capturing the effect of COVID-19 related disruptions on measles burden and vaccination impact. Results: Incorporated with the updated data sources, DynaMICE projected 253 million measles cases, 3.8 million deaths and 233 million DALYs incurred over 2000–2050 in the ten high-burden countries when MCV1, MCV2, and SIA doses were implemented. Compared to no vaccination, MCV1 contributed to 66% reduction in cumulative measles cases, while MCV2 and SIAs reduced this further to 90%. Among the updated determinants, shifting from fixed to linearly-varying vaccine efficacy by age and from static to time-varying case-fatality risks had the biggest effect on MCV impact. While varying the basic reproduction number showed a limited effect, updates on the other four determinants together resulted in an overall reduction of vaccination impact by 0.58%, 26.2%, and 26.7% for cases, deaths, and DALYs averted, respectively. COVID-19 related disruptions to measles vaccination are not likely to change the influence of these determinants on MCV impact, but may lead to a 3% increase in cases over 2000–2050. Conclusions: Incorporating updated evidence particularly on vaccine efficacy and case-fatality risk reduces estimates of vaccination impact moderately, but its overall impact remains considerable. High MCV coverage through both routine immunisation and SIAs remains essential for achieving and maintaining low incidence in high measles burden settings.

Effect of internationally imported cases on internal spread of COVID-19: a mathematical modelling study

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Publication year

2021

Journal title

The Lancet Public Health

Volume

6

Issue

1

Page(s)

e12-e20
Abstract
Abstract
Background: Countries have restricted international arrivals to delay the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). These measures carry a high economic and social cost, and might have little effect on COVID-19 epidemics if there are many more cases resulting from local transmission compared with imported cases. Our study aims to investigate the extent to which imported cases contribute to local transmission under different epidemic conditions. Methods: To inform decisions about international travel restrictions, we calculated the ratio of expected COVID-19 cases from international travel (assuming no travel restrictions) to expected cases arising from internal spread, expressed as a proportion, on an average day in May and September, 2020, in each country. COVID-19 prevalence and incidence were estimated using a modelling framework that adjusts reported cases for under-ascertainment and asymptomatic infections. We considered different travel scenarios for May and September, 2020: an upper bound with estimated travel volumes at the same levels as May and September, 2019, and a lower bound with estimated travel volumes adjusted downwards according to expected reductions in May and September, 2020. Results were interpreted in the context of local epidemic growth rates. Findings: In May, 2020, imported cases are likely to have accounted for a high proportion of total incidence in many countries, contributing more than 10% of total incidence in 102 (95% credible interval 63–129) of 136 countries when assuming no reduction in travel volumes (ie, with 2019 travel volumes) and in 74 countries (33–114) when assuming estimated 2020 travel volumes. Imported cases in September, 2020, would have accounted for no more than 10% of total incidence in 106 (50–140) of 162 countries and less than 1% in 21 countries (4–71) when assuming no reductions in travel volumes. With estimated 2020 travel volumes, imported cases in September, 2020, accounted for no more than 10% of total incidence in 125 countries (65–162) and less than 1% in 44 countries (8–97). Of these 44 countries, 22 (2–61) had epidemic growth rates far from the tipping point of exponential growth, making them the least likely to benefit from travel restrictions. Interpretation: Countries can expect travellers infected with SARS-CoV-2 to arrive in the absence of travel restrictions. Although such restrictions probably contribute to epidemic control in many countries, in others, imported cases are likely to contribute little to local COVID-19 epidemics. Stringent travel restrictions might have little impact on epidemic dynamics except in countries with low COVID-19 incidence and large numbers of arrivals from other countries, or where epidemics are close to tipping points for exponential growth. Countries should consider local COVID-19 incidence, local epidemic growth, and travel volumes before implementing such restrictions. Funding: Wellcome Trust, UK Foreign, Commonwealth & Development Office, European Commission, National Institute for Health Research, Medical Research Council, and Bill & Melinda Gates Foundation.

Effectiveness and cost-effectiveness of eliminating cervical cancer through a tailored optimal pathway: a modeling study

Xia, C., Xu, X., Zhao, X., Hu, S., Qiao, Y., Zhang, Y., Hutubessy, R., Basu, P., Broutet, N., Jit, M., & Zhao, F. (n.d.).

Publication year

2021

Journal title

BMC Medicine

Volume

19

Issue

1
Abstract
Abstract
Background: The World Health Assembly has adopted a global strategy to eliminate cervical cancer. However, neither the optimal pathway nor the corresponding economic and health benefits have been evaluated. We take China as an example to assess the optimal pathway towards elimination and the cost-effectiveness of tailored actions. Methods: A validated hybrid model was used to assess the costs and benefits of alternative strategies combining human papillomavirus vaccination, cervical screening, and treatment of pre-invasive lesions and invasive cancer for females with different immunization history. All Chinese females living or projected to be born during 2015–2100, under projected trends in aging, urbanization, and sexual activity, were considered. Optimal strategies were determined by cost-effectiveness efficiency frontiers. Primary outcomes were cervical cancer cases and deaths averted and incremental cost-effectiveness ratios (ICERs). We employed a lifetime horizon from a societal perspective. One-way and probabilistic sensitivity analyses evaluate model uncertainty. Results: The optimal pathway represents an integration of multiple tailored strategies from females with different immunization history. If China adopts the optimal pathway, the age-standardized incidence of cervical cancer is predicted to decrease to fewer than four new cases per 100,000 women (i.e., elimination) by 2047 (95% confidence interval 2043 to 2050). Compared to the status quo, the optimal pathway would avert a total of 7,509,192 (6,922,744 to 8,359,074) cervical cancer cases and 2,529,873 (2,366,826 to 2,802,604) cervical cancer deaths in 2021–2100, with the discounted ICER being $− 339 (− 687 to − 79) per quality-adjusted life-year. Conclusions: By adopting an optimal pathway from 2021 (namely, the year of the first Chinese Centennial Goals) onwards, cervical cancer could be eliminated by the late 2040s (namely, ahead of the second Chinese Centennial Goals) while saving net economic costs in China.

Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England

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Publication year

2021

Journal title

Science

Volume

372

Issue

6538
Abstract
Abstract
A severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant, VOC 202012/01 (lineage B.1.1.7), emerged in southeast England in September 2020 and is rapidly spreading toward fixation. Using a variety of statistical and dynamic modeling approaches, we estimate that this variant has a 43 to 90% (range of 95% credible intervals, 38 to 130%) higher reproduction number than preexisting variants. A fitted two-strain dynamic transmission model shows that VOC 202012/01 will lead to large resurgences of COVID-19 cases. Without stringent control measures, including limited closure of educational institutions and a greatly accelerated vaccine rollout, COVID-19 hospitalizations and deaths across England in the first 6 months of 2021 were projected to exceed those in 2020. VOC 202012/01 has spread globally and exhibits a similar transmission increase (59 to 74%) in Denmark, Switzerland, and the United States.

Estimating the effectiveness of routine asymptomatic PCR testing at different frequencies for the detection of SARS-CoV-2 infections

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Publication year

2021

Journal title

BMC Medicine

Volume

19

Issue

1
Abstract
Abstract
Background: Routine asymptomatic testing using RT-PCR of people who interact with vulnerable populations, such as medical staff in hospitals or care workers in care homes, has been employed to help prevent outbreaks among vulnerable populations. Although the peak sensitivity of RT-PCR can be high, the probability of detecting an infection will vary throughout the course of an infection. The effectiveness of routine asymptomatic testing will therefore depend on testing frequency and how PCR detection varies over time. Methods: We fitted a Bayesian statistical model to a dataset of twice weekly PCR tests of UK healthcare workers performed by self-administered nasopharyngeal swab, regardless of symptoms. We jointly estimated times of infection and the probability of a positive PCR test over time following infection; we then compared asymptomatic testing strategies by calculating the probability that a symptomatic infection is detected before symptom onset and the probability that an asymptomatic infection is detected within 7 days of infection. Results: We estimated that the probability that the PCR test detected infection peaked at 77% (54–88%) 4 days after infection, decreasing to 50% (38–65%) by 10 days after infection. Our results suggest a substantially higher probability of detecting infections 1–3 days after infection than previously published estimates. We estimated that testing every other day would detect 57% (33–76%) of symptomatic cases prior to onset and 94% (75–99%) of asymptomatic cases within 7 days if test results were returned within a day. Conclusions: Our results suggest that routine asymptomatic testing can enable detection of a high proportion of infected individuals early in their infection, provided that the testing is frequent and the time from testing to notification of results is sufficiently fast.

Estimating the health impact of vaccination against ten pathogens in 98 low-income and middle-income countries from 2000 to 2030: a modelling study

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Publication year

2021

Journal title

The Lancet

Volume

397

Issue

10272

Page(s)

398-408
Abstract
Abstract
Background: The past two decades have seen expansion of childhood vaccination programmes in low-income and middle-income countries (LMICs). We quantify the health impact of these programmes by estimating the deaths and disability-adjusted life-years (DALYs) averted by vaccination against ten pathogens in 98 LMICs between 2000 and 2030. Methods: 16 independent research groups provided model-based disease burden estimates under a range of vaccination coverage scenarios for ten pathogens: hepatitis B virus, Haemophilus influenzae type B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, Streptococcus pneumoniae, rotavirus, rubella, and yellow fever. Using standardised demographic data and vaccine coverage, the impact of vaccination programmes was determined by comparing model estimates from a no-vaccination counterfactual scenario with those from a reported and projected vaccination scenario. We present deaths and DALYs averted between 2000 and 2030 by calendar year and by annual birth cohort. Findings: We estimate that vaccination of the ten selected pathogens will have averted 69 million (95% credible interval 52–88) deaths between 2000 and 2030, of which 37 million (30–48) were averted between 2000 and 2019. From 2000 to 2019, this represents a 45% (36–58) reduction in deaths compared with the counterfactual scenario of no vaccination. Most of this impact is concentrated in a reduction in mortality among children younger than 5 years (57% reduction [52–66]), most notably from measles. Over the lifetime of birth cohorts born between 2000 and 2030, we predict that 120 million (93–150) deaths will be averted by vaccination, of which 58 million (39–76) are due to measles vaccination and 38 million (25–52) are due to hepatitis B vaccination. We estimate that increases in vaccine coverage and introductions of additional vaccines will result in a 72% (59–81) reduction in lifetime mortality in the 2019 birth cohort. Interpretation: Increases in vaccine coverage and the introduction of new vaccines into LMICs have had a major impact in reducing mortality. These public health gains are predicted to increase in coming decades if progress in increasing coverage is sustained. Funding: Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation.

Estimating the impact of reopening schools on the reproduction number of SARS-CoV-2 in England, using weekly contact survey data

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Publication year

2021

Journal title

BMC Medicine

Volume

19

Issue

1
Abstract
Abstract
Background: Schools were closed in England on 4 January 2021 as part of increased national restrictions to curb transmission of SARS-CoV-2. The UK government reopened schools on 8 March. Although there was evidence of lower individual-level transmission risk amongst children compared to adults, the combined effects of this with increased contact rates in school settings and the resulting impact on the overall transmission rate in the population were not clear. Methods: We measured social contacts of > 5000 participants weekly from March 2020, including periods when schools were both open and closed, amongst other restrictions. We combined these data with estimates of the susceptibility and infectiousness of children compared with adults to estimate the impact of reopening schools on the reproduction number. Results: Our analysis indicates that reopening all schools under the same measures as previous periods that combined lockdown with face-to-face schooling would be likely to increase the reproduction number substantially. Assuming a baseline of 0.8, we estimated a likely increase to between 1.0 and 1.5 with the reopening of all schools or to between 0.9 and 1.2 reopening primary or secondary schools alone. Conclusion: Our results suggest that reopening schools would likely halt the fall in cases observed between January and March 2021 and would risk a return to rising infections, but these estimates relied heavily on the latest estimates or reproduction number and the validity of the susceptibility and infectiousness profiles we used at the time of reopening.

Estimation of country-level incidence of early-onset invasive Group B Streptococcus disease in infants using Bayesian methods

Gonçalves, B. P., Procter, S. R., Clifford, S., Koukounari, A., Paul, P., Lewin, A., Jit, M., & Lawn, J. (n.d.).

Publication year

2021

Journal title

PLoS computational biology

Volume

17

Issue

6
Abstract
Abstract
Neonatal invasive disease caused by Group B Streptococcus (GBS) is responsible for much acute mortality and long-term morbidity. To guide development of better prevention strategies, including maternal vaccines that protect neonates against GBS, it is necessary to estimate the burden of this condition globally and in different regions. Here, we present a Bayesian model that estimates country-specific invasive GBS (iGBS) disease incidence in children aged 0 to 6 days. The model combines different types of epidemiological data, each of which has its own limitations: GBS colonization prevalence in pregnant women, risk of iGBS disease in children born to GBS-colonized mothers and direct estimates of iGBS disease incidence where available. In our analysis, we present country-specific maternal GBS colonization prevalence after adjustment for GBS detection assay used in epidemiological studies. We then integrate these results with other epidemiological data and estimate country-level incidence of iGBS disease including in countries with no studies that directly estimate incidence. We are able to simultaneously estimate two key epidemiological quantities: the country-specific incidence of early-onset iGBS disease, and the risk of iGBS disease in babies born to GBS-colonized women. Overall, we believe our method will contribute to a more comprehensive quantification of the global burden of this disease, inform cost-effectiveness assessments of potential maternal GBS vaccines and identify key areas where data are necessary.

Evaluating the impact of a continued maternal pertussis immunisation programme in England: A modelling study and cost-effectiveness analysis

Sandmann, F., Jit, M., Andrews, N., Buckley, H. L., Campbell, H., Ribeiro, S., Sile, B., Stowe, J., Tessier, E., Ramsay, M., Amirthalingam, G., & Choi, Y. H. (n.d.).

Publication year

2021

Journal title

Vaccine

Volume

39

Issue

32

Page(s)

4500-4509
Abstract
Abstract
Introduction: An unexpected resurgence of pertussis cases and infant deaths was observed in some countries that had switched to acellular pertussis vaccines in the primary immunisation schedule. In response to the outbreaks, maternal pertussis vaccination programmes in pregnant women have been adopted worldwide, including the USA in 2011 and the UK in 2012. Following the success of the programme in England, we evaluated the health and economic impact of stopping versus continuing the maternal pertussis immunisation to inform public health policy making. Methods: We used a mathematical model to estimate the number of infant hospitalisations and deaths related to pertussis in England over 2019–2038. Losses in quality-adjusted life years, QALYs, were considered for infants (aged 0–2 months) who survived or died from pertussis, bereaved parents (of infants who died from pertussis), and women with pertussis (aged 20–44 years). Direct medical costs to the National Health Service included infant hospitalisations, maternal vaccinations, and disease in women. Costs and QALYs were discounted at 3.5%. Changes in the incremental cost-effectiveness ratio, ICER, were explored in sensitivity analyses. Results: The model supports continuing the maternal pertussis immunisation programme as a cost-effective intervention at an ICER of £14,500/QALY (2.5% and 97.5%-quantile: £7,300/QALY to £32,400/QALY). Stopping versus continuing the maternal programme results in an estimated mean of 972 (range 582 to 1489) versus 308 (184 to 471) infant hospitalisations annually. Results were most sensitive to the number of hospitalisations and deaths when stopping the maternal programme. At a cost-effectiveness threshold of £30,000/QALY, the probability of the maternal programme being cost-effective was 96.2%. Conclusion: Our findings support continuing the maternal pertussis vaccination programme as otherwise higher levels of disease activity and infant mortality are expected to return. These results have led policy makers to decide to continue the maternal programme in the UK routine immunisation schedule.

Exploring equity in health and poverty impacts of control measures for SARS-CoV-2 in six countries

Sweeney, S., Capeding, T. P. J., Eggo, R., Huda, M., Jit, M., Mudzengi, D., Naylor, N. R., Procter, S., Quaife, M., Serebryakova, L., Torres-Rueda, S., Vargas, V., & Vassall, A. (n.d.).

Publication year

2021

Journal title

BMJ Global Health

Volume

6

Issue

5
Abstract
Abstract
Background Policy makers need to be rapidly informed about the potential equity consequences of different COVID-19 strategies, alongside their broader health and economic impacts. While there are complex models to inform both potential health and macro-economic impact, there are few tools available to rapidly assess potential equity impacts of interventions. Methods We created an economic model to simulate the impact of lockdown measures in Pakistan, Georgia, Chile, UK, the Philippines and South Africa. We consider impact of lockdown in terms of ability to socially distance, and income loss during lockdown, and tested the impact of assumptions on social protection coverage in a scenario analysis. Results In all examined countries, socioeconomic status (SES) quintiles 1-3 were disproportionately more likely to experience income loss (70% of people) and inability to socially distance (68% of people) than higher SES quintiles. Improving social protection increased the percentage of the workforce able to socially distance from 48% (33%-60%) to 66% (44%-71%). We estimate the cost of this social protection would be equivalent to an average of 0.6% gross domestic product (0.1% Pakistan-1.1% Chile). Conclusions We illustrate the potential for using publicly available data to rapidly assess the equity implications of social protection and non-pharmaceutical intervention policy. Social protection is likely to mitigate inequitable health and economic impacts of lockdown. Although social protection is usually targeted to the poorest, middle quintiles will likely also need support as they are most likely to suffer income losses and are disproportionately more exposed.

Exploring surveillance data biases when estimating the reproduction number: With insights into subpopulation transmission of COVID-19 in England

Sherratt, K., Abbott, S., Meakin, S. R., Hellewell, J., Munday, J. D., Bosse, N., Jit, M., & Funk, S. (n.d.).

Publication year

2021

Journal title

Philosophical Transactions of the Royal Society B: Biological Sciences

Volume

376

Issue

1829
Abstract
Abstract
The time-varying reproduction number (R t: the average number of secondary infections caused by each infected person) may be used to assess changes in transmission potential during an epidemic. While new infections are not usually observed directly, they can be estimated from data. However, data may be delayed and potentially biased. We investigated the sensitivity of R t estimates to different data sources representing COVID-19 in England, and we explored how this sensitivity could track epidemic dynamics in population sub-groups. We sourced public data on test-positive cases, hospital admissions and deaths with confirmed COVID-19 in seven regions of England over March through August 2020. We estimated R t using a model that mapped unobserved infections to each data source. We then compared differences in R t with the demographic and social context of surveillance data over time. Our estimates of transmission potential varied for each data source, with the relative inconsistency of estimates varying across regions and over time. R t estimates based on hospital admissions and deaths were more spatio-temporally synchronous than when compared to estimates from all test positives. We found these differences may be linked to biased representations of subpopulations in each data source. These included spatially clustered testing, and where outbreaks in hospitals, care homes, and young age groups reflected the link between age and severity of the disease. We highlight that policy makers could better target interventions by considering the source populations of R t estimates. Further work should clarify the best way to combine and interpret R t estimates from different data sources based on the desired use. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.

From cervical cancer elimination to eradication of vaccine-type human papillomavirus: Feasibility, public health strategies and cost-effectiveness

Jit, M., Prem, K., Benard, E., & Brisson, M. (n.d.).

Publication year

2021

Journal title

Preventive Medicine

Volume

144
Abstract
Abstract
The Director-General of the World Health Organization has called for global action towards elimination of cervical cancer as a public health problem. Cervical cancer is caused by human papillomavirus (HPV), an infectious agent with no non-human reservoir. One way to achieve this is through very high levels of vaccine coverage that could enable global eradication of vaccine-type HPV. Using the case study of India, we show that HPV eradication can meet all the Dahlem and Strüngmann criteria for feasibility of eradication. It can be achieved with 90% gender-neutral HPV vaccine coverage together with 95% coverage in high-risk groups such as female sex workers. Such a strategy would likely be cost-effective compared to no vaccination. Although it would be more costly in the short-term than achieving cervical cancer elimination alone, it would save costs in the long-term by removing or at least sharply reducing the need for preventive measures.

Global and national estimates of the number of healthcare workers at high risk of SARS-CoV-2 infection

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Publication year

2021

Volume

111

Page(s)

205-207

How can the public health impact of vaccination be estimated?

Echeverria-Londono, S., Li, X., Toor, J., De Villiers, M. J., Nayagam, S., Hallett, T. B., Abbas, K., Jit, M., Klepac, P., Jean, K., Garske, T., Ferguson, N. M., & Gaythorpe, K. A. (n.d.).

Publication year

2021

Journal title

BMC public health

Volume

21

Issue

1
Abstract
Abstract
Background: Deaths due to vaccine preventable diseases cause a notable proportion of mortality worldwide. To quantify the importance of vaccination, it is necessary to estimate the burden averted through vaccination. The Vaccine Impact Modelling Consortium (VIMC) was established to estimate the health impact of vaccination. Methods: We describe the methods implemented by the VIMC to estimate impact by calendar year, birth year and year of vaccination (YoV). The calendar and birth year methods estimate impact in a particular year and over the lifetime of a particular birth cohort, respectively. The YoV method estimates the impact of a particular year’s vaccination activities through the use of impact ratios which have no stratification and stratification by activity type and/or birth cohort. Furthermore, we detail an impact extrapolation (IE) method for use between coverage scenarios. We compare the methods, focusing on YoV for hepatitis B, measles and yellow fever. Results: We find that the YoV methods estimate similar impact with routine vaccinations but have greater yearly variation when campaigns occur with the birth cohort stratification. The IE performs well for the YoV methods, providing a time-efficient mechanism for updates to impact estimates. Conclusions: These methods provide a robust set of approaches to quantify vaccination impact; however it is vital that the area of impact estimation continues to develop in order to capture the full effect of immunisation.

How to Prevent Vaccines Falling Victim to Their Own Success: Intertemporal Dependency of Incidence Levels on Indirect Effects in Economic Reevaluations

Sandmann, F., Ramsay, M., Edmunds, W. J., Choi, Y. H., & Jit, M. (n.d.).

Publication year

2021

Journal title

Value in Health

Volume

24

Issue

10

Page(s)

1391-1399
Abstract
Abstract
Objectives: Incremental cost-effectiveness analyses may inform the optimal choice of healthcare interventions. Nevertheless, for many vaccines, benefits fluctuate with incidence levels over time. Reevaluating a vaccine after it has successfully decreased incidences may eventually cause a disease resurgence if switching to a vaccine with lower indirect benefits. Decisions may successively alternate between vaccines alongside repeated rises and falls in incidence and when indirect effects from historic use are ignored. Our suggested proposal aims to prevent suboptimal decision making. Methods: We used a conceptual model of demand to illustrate alternating decisions between vaccines because of time-varying levels of indirect effects. Similar to the concept of subsidies, we propose internalizing the indirect effects achievable with vaccines. In a case study over 60 years, we simulated a hypothetical 10-year reevaluation of 2 oncogenic human papillomavirus vaccines, of which only 1 protects additionally against anogenital warts. Results: Our case study showed that the vaccine with additional warts protection is initially valued higher than the vaccine without additional warts protection. After 10 years, this differential decreases because of declines in warts incidence, which supports switching to the nonwarts vaccine that causes a warts resurgence eventually. Instead, pricing the indirect effects separately supports continuing with the warts vaccine. Conclusions: Ignoring how the observed incidences depend on the indirect effects achieved with a particular vaccine may lead to repeated changes in vaccines at successive reevaluations, with unintended resurgences, economic inefficiencies, and eroding vaccine confidence. We propose internalizing indirect effects to prevent vaccines falling victim to their own success.

HPV16 and HPV18 seropositivity and DNA detection among men who have sex with men: A cross-sectional study conducted in a sexual health clinic in London

King, E. M., Mesher, D., Sonnenberg, P., Linley, E., Panwar, K., Beddows, S., Soldan, K., Borrow, R., Jit, M., & Gilson, R. (n.d.).

Publication year

2021

Journal title

Sexually transmitted infections

Volume

97

Issue

5

Page(s)

382-386
Abstract
Abstract
Objectives Men who have sex with men (MSM) have an increased risk of human papillomavirus (HPV) infection and related diseases compared with men who have sex exclusively with women. From April 2018, there has been a phased roll-out of HPV vaccination offered to MSM aged up to 45 years old who are attending sexual health clinics and HIV clinics in England. The vaccine is most effective if delivered prior to HPV infection. We estimated the proportion of MSM with no current vaccine-type infection and no serological evidence of prior infection, in a study undertaken prior to vaccine introduction. Methods We conducted a cross-sectional study among 484 MSM aged 18-40 years old who attended a sexual health clinic in London between 2010 and 2012. We estimated the prevalence of current and past infection by testing for HPV DNA in anogenital samples and for serum antibodies to HPV16 and HPV18. Results The median age was 30 years (IQR 25-35). The prevalence of HPV16 and HPV18 DNA was 13.2% and 6.2%, respectively. Seropositivity for HPV16 and HPV18 was 28.5% and 17.1%, respectively, with 11.4% seropositive for both types. Seropositivity for the same HPV type was strongly associated with anogenital DNA detection. 279 MSM (57.6%) tested negative for both HPV16 and HPV18 serology and were DNA negative for these two types; only 5 MSM (1.0%) were seropositive and DNA positive for both HPV types. Conclusions This is the first study to determine both the prevalence of HPV DNA in anogenital samples and HPV seroprevalence among MSM attending a sexual health clinic in the UK. Over half of MSM in this study had no evidence of a previous or current infection with either of the high-risk HPV types included in the quadrivalent vaccine, which supports the rationale for opportunistic HPV vaccination of MSM attending sexual health clinics.

Impact of covid-19-related disruptions to measles, meningococcal a, and yellow fever vaccination in 10 countries

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Publication year

2021

Journal title

eLife

Volume

10
Abstract
Abstract
Background: Childhood immunisation services have been disrupted by COVID-19. WHO recommends considering outbreak risk using epidemiological criteria when deciding whether to conduct preventive vaccination campaigns during the pandemic. Methods: We used 2-3 models per infection to estimate the health impact of 50% reduced routine vaccination coverage and delaying campaign vaccination for measles, meningococcal A and yellow fever vaccination in 3-6 high burden countries per infection. Results: Reduced routine coverage in 2020 without catch-up vaccination may increase measles and yellow fever disease burden in the modelled countries. Delaying planned campaigns may lead to measles outbreaks and increases in yellow fever burden in some countries. For meningococcal A vaccination, short term disruptions in 2020 are unlikely to have a significant impact. Conclusion: The impact of COVID-19-related disruption to vaccination programs varies between infections and countries.

Implications of the school-household network structure on SARS-CoV-2 transmission under school reopening strategies in England

Failed generating bibliography.

Publication year

2021

Journal title

Nature communications

Volume

12

Issue

1
Abstract
Abstract
In early 2020 many countries closed schools to mitigate the spread of SARS-CoV-2. Since then, governments have sought to relax the closures, engendering a need to understand associated risks. Using address records, we construct a network of schools in England connected through pupils who share households. We evaluate the risk of transmission between schools under different reopening scenarios. We show that whilst reopening select year-groups causes low risk of large-scale transmission, reopening secondary schools could result in outbreaks affecting up to 2.5 million households if unmitigated, highlighting the importance of careful monitoring and within-school infection control to avoid further school closures or other restrictions.

Importance of patient bed pathways and length of stay differences in predicting COVID-19 hospital bed occupancy in England

Failed generating bibliography.

Publication year

2021

Journal title

BMC health services research

Volume

21

Issue

1
Abstract
Abstract
Background: Predicting bed occupancy for hospitalised patients with COVID-19 requires understanding of length of stay (LoS) in particular bed types. LoS can vary depending on the patient’s “bed pathway” - the sequence of transfers of individual patients between bed types during a hospital stay. In this study, we characterise these pathways, and their impact on predicted hospital bed occupancy. Methods: We obtained data from University College Hospital (UCH) and the ISARIC4C COVID-19 Clinical Information Network (CO-CIN) on hospitalised patients with COVID-19 who required care in general ward or critical care (CC) beds to determine possible bed pathways and LoS. We developed a discrete-time model to examine the implications of using either bed pathways or only average LoS by bed type to forecast bed occupancy. We compared model-predicted bed occupancy to publicly available bed occupancy data on COVID-19 in England between March and August 2020. Results: In both the UCH and CO-CIN datasets, 82% of hospitalised patients with COVID-19 only received care in general ward beds. We identified four other bed pathways, present in both datasets: “Ward, CC, Ward”, “Ward, CC”, “CC” and “CC, Ward”. Mean LoS varied by bed type, pathway, and dataset, between 1.78 and 13.53 days. For UCH, we found that using bed pathways improved the accuracy of bed occupancy predictions, while only using an average LoS for each bed type underestimated true bed occupancy. However, using the CO-CIN LoS dataset we were not able to replicate past data on bed occupancy in England, suggesting regional LoS heterogeneities. Conclusions: We identified five bed pathways, with substantial variation in LoS by bed type, pathway, and geography. This might be caused by local differences in patient characteristics, clinical care strategies, or resource availability, and suggests that national LoS averages may not be appropriate for local forecasts of bed occupancy for COVID-19. Trial registration: The ISARIC WHO CCP-UK study ISRCTN66726260 was retrospectively registered on 21/04/2020 and designated an Urgent Public Health Research Study by NIHR.

Incidence and disease burden of herpes zoster in the population aged ≥50 years in China: Data from an integrated health care network

Sun, X., Wei, Z., Lin, H., Jit, M., Li, Z., & Fu, C. (n.d.).

Publication year

2021

Journal title

Journal of Infection

Volume

82

Issue

2

Page(s)

253-260
Abstract
Abstract
Background: Herpes zoster (HZ) mainly affects elderly and immunocompromised individuals and is characterized by a painful vesicular rash. Data on the epidemiology of HZ, particularly in unvaccinated individuals aged ≥50 years, are still limited in China. Thus, this study aimed to evaluate the epidemiological features, disease burden, and associated risk factors of HZ in the population aged ≥50 years in China. Methods: We evaluated HZ patients who were aged ≥50 years between January 1, 2015 and December 31, 2017 in the electronic health record database of Yinzhou district. HZ and its complications were identified using ICD-10 codes. In addition, post-herpetic neuralgia (PHN) as a complication of HZ was defined as pain occurring or persisting 90 days after rash onset. The disease burden was estimated according to the duration of hospitalization, frequency of visits, pharmacological treatment cost, and examination cost. Cox proportional hazards regression was used to investigate the associated risk factors for HZ. Results: The overall incidence of HZ was 6.64 per 1000 person-years. Of the 4,313 initial episodes from 2015 to 2017, there were 99 recurrent cases. In total, 7.26% and 3.94% of the HZ patients had PHN and other complications, respectively. The average frequency of outpatient visits was significantly lower in patients with initial disease than that in patients with recurrence (3.6 vs. 6.7 per patient). The mean duration of hospital stay was longer in the recurrent episode than that in the initial episode (24.0 vs. 21.6 days). The inpatient and outpatient cost per new-onset HZ was approximately ¥8116.9 and ¥560.2 per patient, respectively. Age; female sex; suburban residency; and presence of immunocompromised disease, hypertension, or diabetes were significantly associated with the development of HZ. Conclusion: The incidence and recurrence rates of HZ showed different trends with increasing age. The presence of HZ-related complications increased the direct medical costs. Our findings help provide a basis for developing appropriate strategies for HZ prevention and control.

Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7

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Publication year

2021

Journal title

Nature

Volume

593

Issue

7858

Page(s)

270-274
Abstract
Abstract
SARS-CoV-2 lineage B.1.1.7, a variant that was first detected in the UK in September 20201, has spread to multiple countries worldwide. Several studies have established that B.1.1.7 is more transmissible than pre-existing variants, but have not identified whether it leads to any change in disease severity2. Here we analyse a dataset that links 2,245,263 positive SARS-CoV-2 community tests and 17,452 deaths associated with COVID-19 in England from 1 November 2020 to 14 February 2021. For 1,146,534 (51%) of these tests, the presence or absence of B.1.1.7 can be identified because mutations in this lineage prevent PCR amplification of the spike (S) gene target (known as S gene target failure (SGTF)1). On the basis of 4,945 deaths with known SGTF status, we estimate that the hazard of death associated with SGTF is 55% (95% confidence interval, 39–72%) higher than in cases without SGTF after adjustment for age, sex, ethnicity, deprivation, residence in a care home, the local authority of residence and test date. This corresponds to the absolute risk of death for a 55–69-year-old man increasing from 0.6% to 0.9% (95% confidence interval, 0.8–1.0%) within 28 days of a positive test in the community. Correcting for misclassification of SGTF and missingness in SGTF status, we estimate that the hazard of death associated with B.1.1.7 is 61% (42–82%) higher than with pre-existing variants. Our analysis suggests that B.1.1.7 is not only more transmissible than pre-existing SARS-CoV-2 variants, but may also cause more severe illness.

Contact

kmj7983@nyu.edu 708 Broadway New York, NY, 10003