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Acellular pertussis vaccines developed in Japan and their application for disease control
1Pediatric Department, Kawasaki Municipal Hospital, Japan.
Insights
Acellular pertussis vaccines show high efficacy and reduced reactogenicity compared to whole-cell vaccines. Expanded immunization for adults and children is recommended for effective pertussis disease control.
Area of Science:
- Immunology
- Vaccinology
- Public Health
Background:
- Acellular pertussis vaccines, containing pertussis toxin and filamentous hemagglutinin (FHA), have been used in Japan since 1981.
- Whole-cell pertussis vaccines are associated with significant reactogenicity.
- Adults are a significant source of pertussis transmission due to waning immunity.
Purpose of the Study:
- To evaluate the immunogenicity, reactogenicity, and efficacy of acellular pertussis vaccines.
- To assess the role of adults in pertussis transmission.
- To recommend strategies for pertussis disease control.
Main Methods:
- Evaluation of antibody responses (anti-pertussis toxin and anti-FHA) in children.
- Assessment of vaccine reactogenicity (fever, local reactions).
- Estimation of vaccine efficacy in children aged 2-8 years and analysis of transmission data.
Main Results:
- Antibody responses to pertussis toxin were comparable or higher than in convalescent patients; anti-FHA responses were significantly higher.
- Acellular vaccines demonstrated reduced reactogenicity compared to whole-cell vaccines, with low rates of fever and local reactions.
- Estimated efficacy was 84% in children aged 2-8 years, with adults identified as a key source of infection.
Conclusions:
- Acellular pertussis vaccines are immunogenic, well-tolerated, and efficacious in children.
- Adults play a crucial role in pertussis transmission, necessitating broader immunization strategies.
- Immunization with acellular pertussis vaccines for both adults and children is recommended for effective pertussis control.
Abstract:
Acellular pertussis vaccines, comprising mainly pertussis toxin and filamentous hemagglutinin (FHA) and used successfully in Japan since 1981, were evaluated. Anti-pertussis toxin antibody responses in children immunized with acellular pertussis vaccines were comparable or higher than in convalescent-stage patients with pertussis, while those for anti-FHA were far higher. Reactogenicity was much less than with whole cell pertussis vaccines: Fever > or = 38 degrees C occurred in 2%-4% of vaccinees; there was little redness > or = 5 cm in diameter at the vaccination site with the first dose but occurred in 7%-8% of vaccinees with subsequent doses. The estimated efficacy of acellular pertussis vaccine in children ages 2-8 years was 84% (95% confidence interval, 71%-91%). Since vaccine-induced immunity weakens after 6-10 years, adults are now a major source of pertussis transmission. The source of infection was an adult in 11.2% (10/89) of cases, and the secondary attack rate was 10.3% (19/185). Immunization with acellular pertussis vaccines for both adults and children is recommended for disease control.