Bordetella pertussis fimbriae type 2 (Fim2) (Fim2)

Bordetella pertussis fimbriae type 2 (Fim2) is a major structural protein and surface appendage of the Gram-negative bacterium Bordetella pertussis, the causative agent of whooping cough [1, 5]. These filamentous structures, classified as type I pili, are essential for the initial stages of infection by mediating the attachment of the bacteria to the ciliated epithelial cells of the human respiratory tract [2, 16]. Fim2 acts as a key virulence factor that facilitates bacterial colonization and biofilm formation, enabling the pathogen to resist host clearance mechanisms [1, 12]. In clinical practice, Fim2 is a critical component of several multi-component acellular pertussis (aP) vaccines, including DTaP and Tdap formulations such as Infanrix and Adacel [3, 11]. Vaccination with Fim2 induces the production of neutralizing antibodies that block bacterial adhesion and prevent the establishment of infection [8, 9]. Although Fim2 is highly immunogenic, B. pertussis can undergo phase variation or serotype switching between Fim2 and Fim3 to evade the host immune response, which poses a challenge for maintaining long-term vaccine-induced immunity [13, 14]. The protein is also known as Agglutinogen 2 and is often co-purified with Fim3 in vaccine preparations to provide broader protection against circulating strains [7, 9].

Other names

Fim2Serotype 2 fimbriaeSerotype 2 fimbrial subunitAgglutinogen 2B. pertussis Fimbriae 2

Induction of neutralizing antibodies to prevent bacterial adhesion and colonization