The original vaccine consisted of killed pertussis bacilli(B. pertussis) and was considered somewhat “dirty.” Side effectssuch as fever and convulsions were common, and healthauthorities in the United States, Japan, and the UnitedKingdom decided that the risk of the vaccine outweighedthe risk of contracting the disease. In all three of these countries,pertussis vaccine was removed from the routine immunizationschedules. Almost immediately, pertussis, which hadbeen held in check, began to occur in epidemics. In 1992, anew vaccine was developed that consists of bacterial fractions,combined with tetanus and diphtheria toxoids. Thisvaccine, called Acell-Immune, or diphtheria–tetanus–acellular pertussis (DTaP), is safe and highly effective andhas been added to the routine immunization schedule. Thevaccine is adsorbed and is used for routine immunization asthe polyvalent preparation diphtheria–tetanus–pertussis(DTP) (at 2, 4, 6, and 15 months and at 4–6 years). Pertussisvaccination is recommended for most children. There is alsoa diphtheria–tetanus whole-cell pertussis (DTwP) vaccine onthe market, but it is considered to be higher in side effectsthan DTaP. Lastly, a DTaP/Hib vaccine preparation is on themarket and is recommended for use only as the fourth dose ofthe series. At present, the only indication is induction of activeimmunity against diphtheria and tetanus toxins and pertussisfrom age 6 weeks up to the seventh birthday.
