Safety follow-up in a cohort of Biken acellular DPT vaccine recipients in Japan.

In October 1984 in Sweden, a phase II trial of Biken acellular Pertussis vaccine was started and in 1986, a phase III trial of the same vaccine was begun. During the phase III trial, there were three cases of deaths out of 1,385 of study children at two, four and ten weeks after the second dose of the vaccine, due to severe invasive bacterial infections such as H. influenzae, Pneumococcus, or Meningococcus infection. A number of arguments arose about the results of the Phase III trial. No one can either prove or disprove the association between invasive bacterial infection and administration of acellular pertussis vaccine. The purpose of this paper is to discuss the side effects of Biken acellular DPT vaccine. The pediatricians inquired about the physical status of the children who received Biken acellular DPT vaccine. During the observation period, three out of 940 infants suffered from infectious diseases. One suffered from measles, the other from varicella and the last from mumps. Our retrospective study did not reveal any severe invasive bacterial infection cases cases such as the ones experienced in Sweden.