Cost effectiveness of pertussis vaccination in adults.

BACKGROUND

Prior economic analyses have reached disparate conclusions about whether vaccinating adults against pertussis would be cost effective. Newly available data on pertussis incidence were used to evaluate the cost effectiveness of one-time adult vaccination and adult vaccination with decennial boosters.

METHODS

A Markov model was used to calculate the health benefits, risks, costs, and cost effectiveness of the following strategies: (1) no adult pertussis vaccination, (2) one-time adult vaccination at 20-64 years, and (3) adult vaccination with decennial boosters. The impact of the severity of pertussis illness, vaccine adverse events, and herd immunity on model outcomes were also examined.

RESULTS

At a disease incidence of 360 per 100,000, the one-time adult vaccination strategy would prevent 2.8 million cases, and the decennial vaccination strategy would prevent 8.3 million cases. As disease incidence varied from 10 to 500 per 100,000, the one-time adult vaccination strategy was projected to prevent 79,000 to 3.8 million adult pertussis cases, while the decennial vaccination program would prevent 239,000 to 11.4 million cases. A one-time adult vaccination strategy would result in 106 million people vaccinated, or approximately 64% of the adult cohort, for a total program cost of $2.1 billion, while a decennial vaccination strategy would cost $6.7 billion. The one-time and decennial booster vaccination strategies result in cost-effectiveness ratios of <$50,000 per quality-adjusted life year saved if disease incidence in adults were greater than 120 cases per 100,000 population.

CONCLUSIONS

Routine vaccination of adults aged 20 to 64 years with combined tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis is cost effective if pertussis incidence in this age group is greater than 120 per 100,000 population.