Acellular and whole-cell pertussis vaccines in Japan. Report of a visit by US scientists
G. R. Noble, R. H. Bernier, E. C. Esber, M. C. Hardegree, A. R. Hinman, D. Klein and A. J. Saah
Since the introduction of acellular pertussis vaccines in Japan late in
1981, more than 20 million doses have been administered, mostly to children
2 years of age and older. Clinical studies indicate that mild local and
febrile reactions are less frequent after administration of acellular
pertussis vaccines than after whole-cell vaccines. Serious adverse events
with sequelae occurred in 2-year-old children at approximately the same low
rate during the period 1975 through August 1981, when whole-cell vaccines
were used, and during August 1981 through 1984, when acellular vaccines
were used exclusively. Five household contact studies have yielded vaccine
efficacy estimates ranging from 78% to 92% in children 1 year of age or
older. In addition, there has been a continuing decrease in reported
pertussis incidence from the epidemic peak in 1979. Additional data on the
safety and efficacy of acellular pertussis vaccines administered to infants
would be useful in consideration of acellular pertussis vaccine licensure
in the United States.
