Cost-Effectiveness of Adolescent Pertussis Vaccination for The Netherlands: Using an Individual-Based Dynamic Model

BACKGROUND: Despite widespread immunization programs, a clear increase in pertussis incidence is apparent in many developed countries during the last decades. Consequently, additional immunization strategies are considered to reduce the burden of disease. The aim of this study is to design an individual-based stochastic dynamic framework to model pertussis transmission in the population in order to predict the epidemiologic and economic consequences of the implementation of universal booster vaccination programs. Using this framework, we estimate the cost-effectiveness of universal adolescent pertussis booster vaccination at the age of 12 years in the Netherlands. METHODS/PRINCIPAL FINDINGS: We designed a discrete event simulation (DES) model to predict the epidemiological and economic consequences of implementing universal adolescent booster vaccination. We used national age-specific notification data over the period 1996-2000--corrected for underreporting--to calibrate the model assuming a steady state situation. Subsequently, booster vaccination was introduced. Input parameters of the model were derived from literature, national data sources (e.g. costing data, incidence and hospitalization data) and expert opinions. As there is no consensus on the duration of immunity acquired by natural infection, we considered two scenarios for this duration of protection (i.e. 8 and 15 years). In both scenarios, total pertussis incidence decreased as a result of adolescent vaccination. From a societal perspective, the cost-effectiveness was estimated at €4418/QALY (range: 3205-6364 € per QALY) and €6371/QALY (range: 4139-9549 € per QALY) for the 8- and 15-year protection scenarios, respectively. Sensitivity analyses revealed that the outcomes are most sensitive to the quality of life weights used for pertussis disease. CONCLUSIONS/SIGNIFICANCE: To our knowledge we designed the first individual-based dynamic framework to model pertussis transmission in the population. This study indicates that adolescent pertussis vaccination is likely to be a cost-effective intervention for The Netherlands. The model is suited to investigate further pertussis booster vaccination strategies

Busy Period Analysis of Multi-Server Retrial Queueing Systems

The literature on the busy period analysis in queueing theory is very limited due to the inherent complexity in its study. Recently, using the simulation approach the busy period for the classical multi-server queueing systems was studied by this author and some interesting observations were reported. In this paper we carry out a similar analysis but on a smaller scale in the case of multi-server retrial queueing systems. It should be pointed out that while the literature on retrial queueing system is vast, the same cannot be said about the busy period analysis in retrial queueing systems. Only a few papers with restricted assumptions are available in the literature. This paper is an attempt to fill the void

Queues with Markovian Arrivals, Phase Type Services, Breakdowns, and Repairs

In service sectors, the server interruptions occur naturally and are studied using queueing models with interruptions. Such models have been studied extensively in the literature. The server interruptions may occur due to external events such as shocks and negative customers, or due to internal events which are dictated by a timer or a clock which when expired may result in an interruption. In this paper, we analyze models of MAP/PH/1-type with phase type breakdowns and phase type repairs analytically. The breakdowns are modeled using internal clocks. The study of such breakdowns in the context of MAP/PH/c-type models is carried out via simulation. Some illustrative examples are discussed