Dataset Information

Childhood varicella-zoster virus vaccination in Belgium: cost-effective only in the long run or without exogenous boosting?

ABSTRACT: AIM: To assess the effectiveness and cost-effectiveness of a universal childhood varicella-zoster vaccination programme in Belgium (1) using the most recent Belgian data on varicella-zoster burden, (2) exploring different options for the timing of the second dose, (3) obtaining results with and without exogenous natural boosting, and (4) investigating the possible additional benefit of zoster booster vaccination for adults at age 50 or 60 y. METHODS: An extensively studied and improved dynamic model is used to estimate primary and breakthrough chickenpox and zoster cases over time. For a range of vaccination options, we compared the direct costs (health care payer perspective) and health outcomes (including Quality-Adjusted Life-Years (QALYs) lost) associated with chickenpox and herpes zoster. Estimates of social contact patterns, health care use, costs and QALY losses are almost exclusively based on Belgian databases and surveys. RESULTS AND CONCLUSIONS: If exogenous natural boosting exists, a net loss in QALYs is expected for several decades after implementing a universal chickenpox vaccination programme, due to an increase in zoster mainly in persons aged 50-80 y. This result holds also for scenarios that minimise or counteract the expected increase in zoster incidence (e.g. additional booster vaccinations in adults). However, if the boosting hypothesis is not true or if costs and QALYs are cumulated over at least 33 to more than 100 y after vaccination (depending on the assumptions made), different options for universal 2-dose vaccination against chickenpox in Belgium would be cost-effective at a vaccine price of €43/dose or lower.

SUBMITTER: Bilcke J

PROVIDER: S-EPMC3903901 | biostudies-other | 2013 Apr

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Childhood varicella-zoster virus vaccination in Belgium: cost-effective only in the long run or without exogenous boosting?

Bilcke Joke J van Hoek Albert Jan AJ Beutels Philippe P

Human vaccines & immunotherapeutics 20130115 4

<h4>Aim</h4>To assess the effectiveness and cost-effectiveness of a universal childhood varicella-zoster vaccination programme in Belgium (1) using the most recent Belgian data on varicella-zoster burden, (2) exploring different options for the timing of the second dose, (3) obtaining results with and without exogenous natural boosting, and (4) investigating the possible additional benefit of zoster booster vaccination for adults at age 50 or 60 y.<h4>Methods</h4>An extensively studied and impro ...[more]

PMID: 23321955

Similar Datasets

Project description:BackgroundA controversy exists about the potential effect of childhood varicella vaccination on Herpes Zoster (HZ) incidence. Mathematical models projected temporary HZ incidence increase after vaccine introduction that was not confirmed by real-world evidence. These models assume that absence of contacts with infected children would prevent exogenous boosting of Varicella-Zoster-Virus (VZV) immunity and they do not include an endogenous VZV immunity-boosting mechanism following asymptomatic VZV reactivation. This study aims to explore the effect of various assumptions on exogenous and endogenous VZV immunity-boosting on HZ incidence in the general population after introduction of routine childhood varicella vaccination.MethodsAn age-structured dynamic transmission model was adapted and fitted to the seroprevalence of varicella in France in absence of vaccination using the empirical contact matrix. A two-dose childhood varicella vaccination schedule was introduced at 12 and 18 months. Vaccine efficacy was assumed at 65%/95% (dose 1/dose 2), and coverage at 90%/80% (dose 1/dose 2). Exogenous boosting intensity was based on assumptions regarding HZ-immunity duration, age-dependent boosting effect, and HZ reactivation rates fitted to observed HZ incidence. Endogenous boosting was the same as pre-vaccination exogenous boosting but constant over time, whilst exogenous boosting depended on the force of infection. Five scenarios were tested with different weightings of exogenous (Exo) - endogenous (Endo) boosting: 100%Exo-0%Endo, 75%Exo-25%Endo, 50%Exo-50%Endo, 25%Exo-75%Endo, 0%Exo-100%Endo.ResultsHZ incidence before varicella vaccination, all ages combined, was estimated at 3.96 per 1000 person-years; it decreased by 64% by year 80 post vaccine introduction, for all boosting assumptions. The 100%Exo-0%Endo boosting scenario, predicted an increase in HZ incidence for the first 21 years post vaccine introduction with a maximum increase of 3.7% (4.1/1000) at year 9. However, with 0%Exo-100%Endo boosting scenario an immediate HZ decline was projected. The maximum HZ incidence increases at 10, 3, and 2 years post vaccination were 1.8% (75%Exo-25%Endo), 0.8% (50%Exo-50%Endo) and 0.2% (25%Exo-75%Endo), respectively.ConclusionsAssuming modest levels of endogenous boosting, the increase in HZ incidence following childhood varicella vaccination was smaller and lasted for a shorter period compared with 100%Exo-0%Endo boosting assumption. Endogenous boosting mechanism could partly explain the divergence between previous HZ-incidence projections and real-world evidence.

Project description:BackgroundThe present study aims to evaluate the cost-effectiveness of the newly introduced varicella and herpes zoster (HZ) vaccination programmes in Italy. The appropriateness of the introduction of the varicella vaccine is highly debated because of concerns about the consequences on HZ epidemiology and the expected increase in the number of severe cases in case of suboptimal coverage levels.MethodsWe performed a cost-utility analysis based on a stochastic individual-based model that considers realistic demographic processes and two different underlying mechanisms of exogenous boosting (temporary and progressive immunity). Routine varicella vaccination is given with a two-dose schedule (15 months, 5-6 years). The HZ vaccine is offered to the elderly (65 years), either alone or in combination with an initial catch-up campaign (66-75 years). The main outcome measures are averted cases and deaths, costs per quality-adjusted life years gained, incremental cost-effectiveness ratios, and net monetary benefits associated with the different vaccination policies.ResultsDemographic processes have contributed to shaping varicella and HZ epidemiology over the years, decreasing varicella circulation and increasing the incidence of HZ. The recent introduction of varicella vaccination in Italy is expected to produce an enduring reduction in varicella incidence and, indirectly, a further increase of HZ incidence in the first decades, followed by a significant reduction in the long term. However, the concurrent introduction of routine HZ vaccination at 65 years of age is expected to mitigate this increase and, in the longer run, to reduce HZ burden to its minimum. From an economic perspective, all the considered policies are cost-effective, with the exception of varicella vaccination alone when considering a time horizon of 50 years. These results are robust to parameter uncertainties, to the two different hypotheses on the mechanism driving exogenous boosting, and to different demographic projection scenarios.ConclusionsThe recent introduction of a combined varicella and HZ vaccination programme in Italy will produce significant reductions in the burden of both diseases and is found to be a cost-effective policy. This programme will counterbalance the increasing trend of zoster incidence purely due to demographic processes.

Project description:ObjectivesComprehensive cost-effectiveness analyses of introducing varicella and/or herpes zoster vaccination in the Swedish national vaccination programme.DesignCost-effectiveness analyses based on epidemiological results from a specifically developed transmission model.SettingNational vaccination programme in Sweden, over an 85- or 20-year time horizon depending on the vaccination strategy.ParticipantsHypothetical cohorts of people aged 12 months and 65-years at baseline.InterventionsFour alternative vaccination strategies; 1, not to vaccinate; 2, varicella vaccination with one dose of the live attenuated vaccine at age 12 months and a second dose at age 18 months; 3, herpes zoster vaccination with one dose of the live attenuated vaccine at 65 years of age; and 4, both vaccine against varicella and herpes zoster with the before-mentioned strategies.Main outcome measuresAccumulated cost and quality-adjusted life years (QALY) for each strategy, and incremental cost-effectiveness ratios (ICER).ResultsIt would be cost-effective to vaccinate against varicella (dominant), but not to vaccinate against herpes zoster (ICER of EUR 200,000), assuming a cost-effectiveness threshold of EUR 50,000 per QALY. The incremental analysis between varicella vaccination only and the combined programme results in a cost per gained QALY of almost EUR 1.6 million.ConclusionsThe results from this study are central components for policy-relevant decision-making, and suggest that it was cost-effective to introduce varicella vaccination in Sweden, whereas herpes zoster vaccination with the live attenuated vaccine for the elderly was not cost-effective-the health effects of the latter vaccination cannot be considered reasonable in relation to its costs. Future observational and surveillance studies are needed to make reasonable predictions on how boosting affects the herpes zoster incidence in the population, and thus the cost-effectiveness of a vaccination programme against varicella. Also, the link between herpes zoster and sequelae need to be studied in more detail to include it suitably in health economic evaluations.

Dataset Information

Childhood varicella-zoster virus vaccination in Belgium: cost-effective only in the long run or without exogenous boosting?

Publications

Childhood varicella-zoster virus vaccination in Belgium: cost-effective only in the long run or without exogenous boosting?

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets