Acellular pertussis vaccine antigens (aP antigens)

Acellular pertussis vaccine antigens Overview

Acellular pertussis vaccines contain purified components of Bordetella pertussis rather than the entire inactivated organism used in whole-cell vaccines. These components include inactivated pertussis toxin either alone or in combination with other bacterial components such as filamentous hemagglutinin, fimbrial antigens, and pertactin. The vaccines vary in the number of components they contain, with some having just one component (PT) while others contain up to five (PT, FHA, PRN, FIM2, FIM3). In systematic reviews, acellular pertussis vaccines with at least three components (PT, FHA, and PRN) demonstrated higher efficacy against pertussis in clinical trials compared to vaccines with fewer components. Acellular pertussis vaccines prevent around 85% of typical whooping cough cases in children. However, their efficacy declines faster than some whole-cell pertussis vaccines, and recent evidence suggests they may have limited impact on infection and transmission, meaning vaccinated individuals could spread the disease even with mild or no symptoms. A notable concern is the emergence of pertactin-deficient B. pertussis strains, with up to 85% of isolates in the U.S. lacking this component. This is significant because antibody response to pertactin is more durable than responses to PT and fimbrae, and pertactin antibodies are believed to be more effective at blocking colonization.

Mechanism of Action

The acellular pertussis vaccine components work by: - Inducing antibody production against specific Bordetella pertussis antigens - Providing protection against pertussis disease symptoms - Potentially limiting bacterial colonization and transmission

Biological Functions

Safety Considerations

Interacting Drugs

Associated Biomarkers