Inmunogenicidad y reactogenicidad de una vacuna de difteria, tétanos, pertussis acelular de contenido antigénico reducido, dTpa, en niños de 10 a 11 años de edad y en adultos / Immunogenicity and reactogenicity of a reduced antigen content diphteria, tetanus, acellular pertussis vaccine, dTpa, in 10 to 11 years old children and in adults

RESUMO

Background: New vaccination strategies are needed to control the increasing problem of pertussis in teenagers and adults. Aim: To determine the immunogenicity and reactogenicity of a diphtheria-tetanus-acellular pertussis (dTpa) vaccine with reduced antigen content. Material and Methods: A single dose of the dTpa vaccine was administered to 60 children 10 to 11 years old and 60 healthy adults. At the moment of vaccination and one month later, antibody levels were measured against 3 B pertussis antigens anti-pertussis toxin (PT), anti-pertactin (PRN) and anti-filamentous hemagglutinin (FHA), as well as anti-tetanus and anti-diphtheria antibodies. Local and general symptoms were registered during 14 days following vaccine administration. Results: Antibody response for PT, FHA and PRN was 98.3 percent, 100 percent and 100 percent in adults and 98.2 percent, 100 percent and 98.2 percent in children. Seropositivity for all pertussis antigens was 100 percent in adults and in children one month after vaccination. Geometric mean titers (GMT) significantly increased in adults and children. The seroprotection level achieved for tetanus and diphtheria antibodies one month after vaccination was 96.7 percent for adults and 100 percent for children, respectively. No serious adverse events were reported during the study. Among local symptoms pain was the most frequent (88-90 percent), but it was mostly mild or moderate. Solicited general symptoms observed for children and adults, respectively, included headache (37 percent and 53 percent), fatigue (18 percent and 35 percent) gastrointestinal symptoms (18 percent and 25 percent) and fever (8 percent and 3 percent). Only one vaccinee had fever above 39­C. Conclusions: the dTpa vaccine showed an adequate safety profile and induced an intense immunological response to all antigens in adults and children aged 10-11