Immunization schedules and avidity assay against respiratory bovine disease bacteria in cattle

DÍAZ AILÉN MAGALÍ; ALMOZNI B; SOTELO A; MANGONE F; CANELLADA AM; CASTRO MS

CABA

Congreso; Reunión Conjunta de Sociedades Biomédicas; 2017

Sociedad Argentina de Inmunología

Livestock production is exposed to many adverse conditions which threaten animal health as the Respiratory Bovine Disease (RBD). Although commercial vaccines are employed, protective immune responses are not well understood and immunodiagnostic methods are not well defined. This work aimed to employ an indirect in-house ELISA and develop an avidity assay to study bovine immune response against the bacterial agents: Pasteurella multocida (PM), Mannheimia haemolytica (MH), Histophilus somni (HS).Freshly weaned 2-month calves were employed in 2 different immunization schedules. The 1st plan (n=10) received 3 doses (every 21 days) of the commercial vaccine BiopoligenHS (CV) or an experimental vaccine (EV) formulated with inactivated culture supernatant of PM and aluminum. The 2nd plan (n=7) was immunized with 2 doses (days 0 and 21) employing the CV or an EV either with PM or MH formulated with a polymeric adjuvant, Montanide Gel01. A control cow inoculated only with adjuvant was included in both schedules. Calves were bled on days 0, 21, 42 and 60, depending the schedule. Specific IgG and IgM were measured by ELISA, and for the avidity assay an adaptation was tested employing urea as dissociating agent. In the 1st plan, IgG levels were higher for CV compared to PM supernatant and with the placebo (p