Reactogenicity of a three-dose pertussis acellular vaccine catch-up in children 21-40 months of age

The reactogenicity of a three-dose catch-up acellular pertussis (aP) immuni zation of children at 21-40 months of age was evaluated. Vaccination was we ll-tolerated: fever greater than or equal to 38 degrees C was reported afte r 5% of administered doses and local reactions after 14-15%. The onset of a dverse events was not associated with age at vaccination, interval between doses or previous presence of antibodies against pertussis, whereas injecti on in sites other than the buttock and presence of the same symptom after a previous dose were associated with higher reactogenicity. Because of the g ood safety profile of primary aP immunization in children > 1 year of age, catch-up vaccination campaigns could be considered in areas where pertussis whole-cell vaccination uptake has been low and where the number of suscept ible children should be reduced to control pertussis circulation. (C) 1999 Elsevier Science Ltd. All rights reserved.