Livestock Vaccine Safety & Immunogenicity for Veterinary Biotech
The Challenge
A veterinary biotechnology startup had developed a novel recombinant subunit vaccine targeting bovine respiratory disease complex (BRDC), the leading cause of economic loss in the North American cattle industry. The company needed to generate the safety and immunogenicity data required for a USDA Center for Veterinary Biologics (CVB) conditional license application. The vaccine platform was novel, requiring careful dose optimization and a controlled challenge study to demonstrate clinical protection. The startup had limited in-house capabilities and needed a contract research facility with large-animal housing, BSL-2 containment for challenge studies, and experience navigating the USDA licensing pathway.
Our Solution
Meramec leveraged our 200-head cattle research facility and BSL-2 large-animal containment unit to design a three-phase program. Phase 1: Dose-ranging study in 40 calves evaluating 4 antigen concentrations with and without adjuvant, measuring serum antibody titers by ELISA and virus neutralization assay at days 0, 21, 35, and 56 post-vaccination. Phase 2: Repeat-dose safety study at 2x the selected dose in 30 calves, monitoring injection site reactions, rectal temperature, clinical signs, body weight, hematology, and clinical chemistry over 60 days. Phase 3: Controlled challenge study in 60 calves (30 vaccinated, 30 controls) using virulent Mannheimia haemolytica and bovine herpesvirus-1, with daily clinical scoring, lung ultrasonography, nasal shedding quantification, and post-mortem lung lesion scoring. All studies conducted per USDA 9 CFR 113 requirements with GLP documentation.
The Results
The dose-ranging study identified an optimal antigen-adjuvant combination that induced seroconversion in 100% of animals by day 35. The safety study demonstrated excellent tolerability with only mild, transient injection site swelling in 10% of animals. In the challenge study, vaccinated calves showed an 87% reduction in clinical disease scores compared to controls (P<0.001), with 93% seroconversion durability at 6 months. Lung lesion scores at necropsy were reduced by 76% in vaccinates. The comprehensive data package exceeded USDA CVB expectations, and the conditional license was granted 3 months ahead of the projected timeline. The client successfully launched the vaccine for the fall vaccination season, generating $2.3M in first-year revenue.