Cost-effectiveness of adult pertussis vaccination in Germany.

Background: The incidence of pertussis in adults is high despite good childhood vaccination coverage. An adult formulation of an acellular pertussis vaccine is licensed and available for use in Germany.
Objective: To evaluate the potential health benefits, risks, costs and cost-effectiveness of routine pertussis vaccination programs for German adults.
Methods: A Markov model was used to simulate health states and immunity levels associated with pertussis disease and vaccination. The following strategies were evaluated: (1) no adult pertussis vaccination, (2) one-time adult vaccination at 20-64 years, and (3) adult vaccination with decennial boosters. Our main outcome measures were costs (2006 Euros), cases prevented, incremental cost per case prevented and incremental cost per quality-adjusted life year (QALY) saved. We performed sensitivity analyses for key assumptions in the model including disease incidence, vaccine cost, vaccine efficacy, disease costs and frequency of adverse events. Future costs and benefits were discounted at 3%.
Results: At a disease incidence of 165 per 100,000, the one-time adult vaccination strategy would prevent 498,000 cases, and the decennial adult vaccination strategy would prevent 1 million cases. Approximately 31 million adults ( approximately 62% of the cohort) would be vaccinated with a one-time adult vaccination strategy for a total program cost of 366 million Euros, while a decennial vaccination strategy would cost 687 million Euros. The one-time adult vaccination strategy resulted in CE ratios of 5800 Euros per QALY saved, or 160 Euros per pertussis case prevented. The decennial booster strategy cost 7200 Euros per QALY saved, or 200 Euros per case prevented. The results were most sensitive to assumptions about disease incidence and vaccine cost.
Conclusions: Routine vaccination of German adults aged 20-64 years with Tdap is cost-effective.