Three doses of the two-component acellular pertussis vaccine protected infants against pertussis disease during the period before the recommended booster vaccination. For typical pertussis disease as defined by the WHO efficacy was high and similar to that of a licensed German diphtheria-tetanus toxoids-whole cell pertussis vaccine.

In comparison with a fourth dose of Biken DTaP administered at 18 to 24 months of age in the same population, the rate of local reactions increased after the fifth dose, whereas systemic reactions remained similarly low or decreased.

A booster dose of Td-IPV induced in all children seroprotection against tetanus, diphtheria and poliomyelitis. The overall safety profile of the two vaccines was acceptable.

No abstract