Lifecycle model-based evaluation of infant 4CMenB vaccination in the UK.

OBJECTIVES: Invasive meningococcal disease, an uncommon but severe disease, imposes catastrophic health and economic burdens. Cost-utility analysis (CUA) assumes separability in lifetime health and economic variables and cannot capture the full value of preventing such burdens. We overcome these limitations with a retrospective societal perspective cost-benefit analysis (CBA) of meningococcal serogroup B vaccination (4CMenB) of one infant cohort in the United Kingdom using a health-augmented lifecycle model (HALM) incorporating health's interactions with consumption, earnings, non-market time and financial risk. METHODS: We used a static Markov model of vaccination's health impact and an HALM to estimate the private willingness to pay (PWTP) for the intrinsic and instrumental value of health under perfect capital markets, financial risk protection in the absence of insurance against permanent disability, parental spillovers, and acute phase disability. We estimated social WTP (SWTP) incorporating social severity preferences. We estimated rates of return that inform health payer reimbursement decisions, finance ministry budgeting decisions, and legislature taxation decisions. An expert Advisory Board investigated the validity of applying the HALM to infant 4CMenB. RESULTS: The PWTP for a 2 + 1 vaccination schedule is £395, comprising £166 of disability insurance value, £79 of positive parental spillover value, £28 in the value of averting acute phase disability, and £122 in residual intrinsic and instrumental value of health. SWTP is £969. CONCLUSIONS: HALM-based CBA provides an empirically richer, more utility-theoretically grounded approach to vaccine evaluation than CUA, demonstrating good value for money for legislatures (based on private values) and for all decision-makers (based on social values).

Long-Term Mortality and State Financial Support in Invasive Meningococcal Disease-Real-World Data Analysis Using the French National Claims Database (SNIIRAM).

OBJECTIVES: Invasive meningococcal disease (IMD) is an uncommon disease known for its acute phase mortality and long-term sequelae. The objective was to assess the impact of IMD on post-discharge mortality risk and dependence on the French state for financial aid. METHODS: A 6-year retrospective analysis in the national insurance database (SNIIRAM) assessed mortality in IMD cases (both during acute phase and post-discharge) and matched controls as well as benefit claims (i.e., for salary loss compensation [SLC], long-term sickness [ALD] and complementary health insurance [CMUc]). Observed survival data were extrapolated to estimate lifetime life expectancy following IMD. RESULTS: Between 2012 and 2017, 3532 incident IMD cases were hospitalised in France (peak in < 2 years and 15-24 year olds), of which 23.3% developed sequelae. With an average follow-up of 2.8 years, 12.9% of cases vs. 3.2% of controls died (p < 0.0001), with significantly more cases than controls dying both during the acute phase and post-discharge. Around a third of these deaths occurred post-discharge. Extrapolation to lifetime life expectancy estimated that having IMD at any age significantly reduces life expectancy in survivors of the acute disease phase, e.g., by around 16 years for cases aged 0-50 years. IMD cases in France were significantly more likely to receive state-funded SLC (relative risk [RR] 3.9, 95% confidence interval [95% CI] 2.3-6.4) and ALD benefits (RR 1.85, 95% CI 1.71-2.00). CONCLUSIONS: IMD has a significant impact on mortality post-discharge, expected to persist over a lifetime. In addition to long-term sequelae, the financial burden extends beyond the healthcare sector. These results highlight the importance of IMD prevention (e.g., vaccination).

Invasive meningococcal disease (IMD) is an uncommon disease mainly affecting children, with severe consequences such as a risk of dying within hours of symptoms and a risk of developing long-term conditions affecting health, learning and ability to work. Little is known of the risk of dying in survivors after discharge from hospital or of survivors' financial support needs. The French national insurance claims database (SNIIRAM) was reviewed for data on IMD patients hospitalised between 2012 and 2017 and matched controls without IMD. Data, available following IMD hospitalisation for an average of around 3 years, were extrapolated to estimate the lifelong impact of the disease. Among 3532 hospitalised IMD cases, the study found that nearly 13% died, of which a third of deaths occurred post-discharge. The cases who survived the acute disease phase were also more likely to require government funds because of loss of salary or to cover long-term healthcare costs. In addition to the well-known acute phase burden of IMD, this study has shown that there is a long-term effect on risk of dying and on need for government support. This demonstrates the importance of prevention, for example, by vaccination.

A Data-Driven Simulation of HIV Spread Among Young Men Who Have Sex With Men: Role of Age and Race Mixing and STIs.

OBJECTIVE: Young men who have sex with men (YMSM) in the United States have a high HIV incidence with substantial racial disparities that are poorly understood. We use a data-driven simulation model to understand the impact of network-level mechanisms and sexually transmitted infections on the spread of HIV among YMSM. METHODS: We designed and parameterized a stochastic agent-based network simulation model using results of a longitudinal cohort study of YMSM in Chicago. Within this model, YMSM formed and dissolved partnerships over time, and partnership types were stratified by length of partnership, sex, and age of the partner. In each partnership, HIV, gonorrhea, and chlamydia could be transmitted. Counterfactual scenarios were run to examine drivers of HIV. RESULTS: Over a 15-year simulation, the HIV epidemic among YMSM continued to rise, with Latino/white YMSM facing a steeper increase in the HIV burden compared with black YMSM. YMSM in partnerships with older MSM, in particular black YMSM with older black MSM, were at highest risk for HIV, and 1 infection prevented with an older partner would prevent 0.8 additional infections among YMSM. Additionally, racial disparities in HIV were driven by differences in the HIV prevalence of YMSM partners. Finally, of all HIV infections among YMSM, 14.6% were attributable to NG and CT infections. CONCLUSION: Network-level mechanisms and sexually transmitted infections play a significant role in the spread of HIV and in racial disparities among YMSM. HIV prevention efforts should target YMSM across race, and interventions focusing on YMSM partnerships with older MSM might be highly effective.

The importance of extended high viremics in models of HIV spread in South Africa.

Recent studies found a substantial fraction of 'extended high viremics' among HIV-1 subtype C, the most common subtype in southern Africa. Extended high viremics are HIV infected individuals who maintain a high viral load for a longer time period than usual after the initial infection. They are more infectious during this period, and their infection progresses to full-blown AIDS and death much faster than usual. This study investigates the impact of extended high viremics on the spread of the HIV epidemic in South Africa. We develop a simple deterministic compartmental model for HIV infection that includes extended high viremics. As the available data on extended high viremics are limited, we parameterize this model using only the fraction of extended high viremics among new infections and the reduced life-span of extended high viremics. We find that without extended high viremics, the HIV prevalence in South Africa would have remained close to its 1990 level, instead of increasing to the current epidemic levels. We also find that the greater the fraction of extended high viremics among susceptibles, the greater the steady-state HIV prevalence and the more sensitive the steady-state prevalence is to the HIV transmission probability. These results suggest that extended high viremics have an impact on the HIV epidemic in South Africa; justify the need for comprehensive epidemiological studies since the current data is limited; and suggest that future models of HIV for southern Africa should explicitly model extended high viremics.