Mass vaccination of children with pertussis toxoid - Decreased incidence in both vaccinated and nonvaccinated persons

During 1979-1995, there was no vaccination against pertussis in Sweden. Wit h the aim of studying the epidemiology and transmission of pertussis, mass vaccination with pertussis toxoid of children born during the 1990s was ins tituted in the Goteborg area (population, 778,597) in 1995. Infants were of fered 3 doses of pertussis toxoid combined with diphtheria and tetanus toxo ids. Children aged greater than or equal to1 year were offered 3 doses of p ertussis toxoid alone. From June 1995 through February 1999, 167,810 doses of pertussis toxoid were given to 61,219 children born during the 1990s (56 % received 3 doses). The number of Bordetella pertussis isolates per year d eclined from 1214 (1993-1995) to 64 (January 1997 through June 1999; P<.000 1), and hospitalizations due to pertussis declined from 62 to 5 (P<.0001). Significant decreases in B. pertussis isolates and hospitalizations occurre d in all age groups, including adults and nonvaccinated infants. Thus, mass vaccination of children with pertussis toxoid decreases spread of B. pertu ssis in the population.