Pasteurella multocida surface antigens (serotypes A:1, A:3, A:4, A:3x4) (P. multocida surface antigens)

Pasteurella multocida surface antigens from serotypes A:1, A:3, A:4, and the cross-reactive A:3x4 (often associated with the CU strain) are the primary targets for immunoprophylaxis against pasteurellosis in livestock and poultry (Bioveta, 2025; NIH, 2023). These antigens comprise a diverse array of molecules, including outer membrane proteins (OMPs) like OmpA, OmpH, and PlpE, as well as lipopolysaccharides (LPS) and capsular polysaccharides (MDPI, 2026; NIH, 2025). Biologically, these surface components are vital for bacterial virulence, facilitating adhesion to host respiratory epithelia, nutrient acquisition, and evasion of the host's innate immune responses, such as complement-mediated killing (NIH, 2023; WOAH, 2024). In poultry, these specific serotypes are the leading cause of fowl cholera, an acute and often fatal septicemic disease, while in ruminants, they are key contributors to the bovine respiratory disease (BRD) complex, also known as shipping fever (Cornell, 2024; NIH, 2025). Vaccines utilizing these antigens, such as inactivated bacterins or subunit vaccines like ORNIVAC FC, aim to induce high titers of protective antibodies that opsonize the bacteria for phagocytosis or neutralize their toxic effects, thereby reducing clinical signs and mortality in affected flocks and herds (Bioveta, 2025; Fortune Business Insights, 2025).

Other names

Pasteurella multocida somatic antigensPasteurella multocida outer membrane proteinsP. multocida LPSP. multocida capsular antigensP. multocida serotype A antigensP. multocida OMPs

Active immunization to induce humoral and cellular immune responses against surface-exposed bacterial epitopes, leading to opsonization, phagocytosis, and neutralization of the pathogen.