Economic evaluation of universal BCG vaccination of Japanese infants

Background The international controversy surrounding the use and effectiven ess of the Bacillus Calmette-Guerin (BCG) vaccine and the low incidence of tuberculosis (TB) among Japanese children prompted this study. Methods We compared 'universal BCG vaccination' with 'no vaccination at all ' using a cost-effectiveness analysis. The study population was a hypotheti cal cohort comprising a total of 1.2 million infants born in 1996 at locati ons all over Japan. A model was developed to calculate the number of TB cas es prevented by the vaccination programme. Assuming 40-80% overall vaccine efficacy (64-86% for TB-meningitis) and 10 years of protection, we calculat ed the cost and number of immunizations required to prevent one child from developing TB, the total number of TB cases averted by vaccination and tota l costs required for the programme. Results Based on an assumption of flexible vaccine efficacy (40-80%), we es timated that 111-542 TB cases including 10-27 of TB-meningitis would be pre vented during the 10 years after BCG vaccination among the cohort of infant s born in 1996. About US$35 950-175 862 or 2125-10 399 immunizations would be required to prevent one child from developing TB. Sensitivity analyses c overing a wide duration of protection, incidence of TB, vaccine coverage an d discount rate, revealed that other than vaccine efficacy, the cost of pre venting a single case of TB is highly sensitive to the duration of BCG prot ection and TB incidence. Conclusion The cost per case of TB prevented is heavily dependent on vaccin e efficacy and the duration of protection, and is high compared with the co st of treating one child who has developed TB.