Table 5.

DTaP and DTP Vaccine Efficacy Against Typical Pertussis as a Result of Bordetella pertussis Infection Using the Principal Primary Case Definition and the Modified WHO Clinical Criteria for the Secondary Case Definition*

VaccineNo. Cases/
No. Exposed
(Attack Rate)
%
Vaccine
Efficacy
95%
Confidence
Interval
Ignoring Antibiotic Use in Exposed Study Children (7–42 Day Postexposure Observation Period)
 DT14/34 (41%)
 DTP 2/65 (3%)9369 –98
 DTaP 4/61 (7%)8455 –94
Exclusion of Noncases Who Received Macrolide Antibiotics or Trimethoprim-Sulfamethoxazole During the 7–42 Day Postexposure Observation Period
 DT14/21 (67%)
 DTP 2/52 (4%)9477 –99
 DTaP 4/42 (10%)8662 –95
  • Abbreviations: DTaP, diphtheria-tetanus toxoids, acellular pertussis vaccine, adsorbed; DTP, diphtheria-tetanus toxoids, whole cell pertussis vaccine, adsorbed; WHO, World Health Organization; DT, diphtheria-tetanus toxoids vaccine.

  • * See Tables 1 and 2.