Placebo-controlled trial of two acellular pertussis vaccines in Sweden--protective efficacy and adverse events. Ad Hoc Group for the Study of Pertussis Vaccines

Lancet. 1988 Apr 30;1(8592):955-60.


3801 children aged 5-11 months were entered into a blind placebo-controlled trial of pertussis vaccine. 954 were randomised to receive placebo (vaccine solvent), 1419 to receive a two-component vaccine containing formaldehyde detoxified lymphocytosis promoting factor (LPF) and filamentous haemagglutinin, and 1428 to receive an LPF-toxoid vaccine. After 7-13 weeks 3724 infants received a second dose. Immediate side-effects were mild. Small local reactions occurred more often in the vaccinated infants than in those who received placebo, especially after the second dose of the two-component vaccine. During 15 months of follow-up from 30 days after the second dose, culture-confirmed whooping cough (cough and a positive culture of Bordetella pertussis) occurred in 40 placebo, 27 LPF-toxoid vaccine, and 18 two-component vaccine recipients. The point estimate of protective efficacy was 54% (95% confidence intervals 26-72%) for the LPF-toxoid vaccine and 69% (47-82) for the two-component vaccine; protection against culture-confirmed whooping cough of over 30 days duration was 80% (59-91%) and 79% (57-90%), respectively.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antibodies, Bacterial / biosynthesis
  • Bordetella pertussis / immunology
  • Clinical Trials as Topic
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Infant
  • Pertussis Vaccine / administration & dosage
  • Pertussis Vaccine / adverse effects
  • Pertussis Vaccine / immunology*
  • Random Allocation
  • Sweden
  • Whooping Cough / prevention & control*


  • Antibodies, Bacterial
  • Pertussis Vaccine