Cost-effectiveness analysis of the Lyme disease vaccine.

OBJECTIVE A vaccine for Lyme disease was approved in 1998 for use in the US. Given the high cost of the vaccine, the low risk of Lyme disease in many areas, and the largely curable nature of the disease, the cost-effectiveness of the vaccine in various risk groups is uncertain. This study was undertaken to examine the cost-effectiveness of the Lyme disease vaccine and the factors that influence its cost-effectiveness. METHODS We constructed a Markov decision-analysis model to evaluate the clinical effectiveness and cost-effectiveness of the Lyme disease vaccine in populations at various levels of risk for the disease. The probabilities of clinical events and costs were estimated from reports in the literature. Sensitivity analyses assessed the impact of potential variations of parameters on model results. RESULTS At the average national incidence of Lyme disease (0.0067%), the incremental cost-effectiveness of vaccination was approximately $1,600,000 per case averted when a yearly booster was given for 10 years after the standard initial vaccination regimen of 3 inoculations at 0, 1, and 12 months. For populations with an annual Lyme disease incidence of 1% (the incidence in several well-defined geographical areas of the US), the incremental cost-effectiveness was approximately $9,900 per case averted. Disease incidence had to exceed 10% before vaccination with yearly boosters became both more effective and more cost saving than no vaccination. CONCLUSION The Lyme disease vaccine is cost-effective only for individuals who live in areas where Lyme disease is endemic and who are frequently exposed to ticks.