Acellular pertussis vaccines: new preparation. Better tolerated but less active?

(1) In France SmithKline Beecham market a three-component acellular pertussis vaccine in the form of a tetravalent vaccine and a pentavalent vaccine. Pasteur M/erieux MSD also market in France a two-component acellular pertussis vaccine in the form of a tetravalent vaccine and a pentavalent vaccine. (2) The two pentavalent vaccines are indicated for an early booster injection at age 16-18 months; the two tetravalent vaccines are indicated for a late booster injection at age 11-13 years. (3) The published assessment file on these vaccines is limited. (4) Immunological studies show that the acellular pertussis valency does not reduce the antigenicity of the valencies with which it is combined (diphtheria, tetanus and poliomyelitis), although there is some doubt regarding the Haemophilus influenzae tybe b valency. (5) In the absence of direct comparisons with the cellular pertussis vaccine available in France in tetravalent or pentavalent vaccines, indirect evidence and data from a trial comparing the acellular two-component vaccine with the cellular vaccine (Vaxicoq degrees ) marketed in France (combined with diphtheria and tetanus valencies) suggest that clinical protection is slightly lower after primary vaccination with the two acellular vaccines. (6) In children, acellular pertussis vaccines are globally better tolerated than the cellular pertussis vaccine. (7) In adolescents, a small study has shown that the three-antigen acellular pertussis vaccine is relatively well tolerated. But the acellular vaccine was released too recently onto the international market to know the precise incidence of rare and severe adverse effects. (8) The new French vaccination schedule for pertussis now includes a booster between 11 and 13 years. Only long-term epidemiological follow-up can show if routine vaccination of adolescents against pertussis will have an impact on the incidence of pertussis in infants and adults. (9) The incidence of Haemophilus b meningitis must continue to be monitored.