DTP vaccine

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A vaccine containing diphtheria and tetanus toxoids and antigenic components of the bacterium that causes pertussis, administered intramuscularly to immunize children against diphtheria, tetanus, and pertussis infections. Since 2002 in the United States, the whole-cell pertussis component has been replaced with a safer acellular component, designated aP.