Acellular pertussis vaccines in diverse populations: a review of effectiveness, immunogenicity, and safety

Pertussis remains an important vaccine-preventable respiratory disease, particularly in young infants. Because of their lower reactogenicity, acellular pertussis vaccines have replaced whole-cell vaccines in many countries and are widely used for infant primary immunization, booster vaccination in children, adolescents and adults, and maternal immunization. However, pertussis resurgence, waning immunity, antigen-deficient circulating strains and limited effects on nasopharyngeal colonization have renewed interest in antigen composition, immune mechanisms and clinical protection. This narrative review synthesizes evidence on acellular pertussis vaccines across different populations, focusing on: clinical protection and waning after infant and childhood vaccination; immunogenicity and safety of adolescent and adult boosters; maternal vaccination and its effects on early infant protection and subsequent immune responses; and product-specific evidence on combination vaccination and coadministration. Rather than attempting an exhaustive comparison of all products and studies, this review highlights representative clinical evidence and distinguish clinical outcomes from immunogenicity and safety endpoints. Current data indicate that pertussis toxin-containing acellular vaccines induce clear antibody responses, and multicomponent formulations broaden antigenic coverage. Three-component or higher acellular vaccines have shown efficacy of approximately 84–85% against typical childhood pertussis, but protection after DTaP wanes over time. DTaP and Tdap are generally well tolerated; most adverse events are mild-to-moderate local or transient systemic reactions. Maternal Tdap improves early infant antibodies but may blunt some subsequent infant responses. Future research should define correlates of protection, evaluate antigen variation, and strengthen evidence on mucosal immunity, coadministration, real-world effectiveness and long-term safety.