To investigate whether a tea saponin–soybean oil submicron emulsion could improve the durability, breadth, and protective efficacy of immune responses induced by an inactivated Pasteurella multocida vaccine.
Approach:
Formulation Characterization: Characterized TS-Pm for particle size, polydispersity, surface charge, morphology, and storage stability.
In Vitro Studies: Examined macrophage antigen uptake, cytokine secretion, and activation-associated surface markers.
In Vivo Studies: Evaluated antibody persistence, B-cell differentiation, splenic cellular immunity, and protection after lethal challenge in mice.
Proteomic Analysis: Conducted draining lymph-node proteomic profiles to identify immune programs associated with TS-Pm immunization.
Key Findings:
TS-Pm formed a stable oil-in-water submicron emulsion of approximately 300 nm with low polydispersity and negative surface charge.
Increased macrophage antigen uptake and pro-inflammatory cytokine production were observed.
TS-Pm maintained higher Pm-specific IgG responses and enhanced B-cell responses compared to the alum-adjuvanted vaccine.
Survival rate improved to 90% after lethal challenge, compared to 60% for Alum-Pm.
Reduced pulmonary bacterial burden and lung pathology were noted without systemic injury.
Updated 2025-2026 vaccination was linked to added protection in a CDC-funded analysis that became part of a broader debate over routine vaccine monitoring.
Federal prosecutors allege that a Florida physician and research staff fabricated clinical trial records that were submitted into database systems used to evaluate investigational drugs.
