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These data and analyses support the research article “Re-evaluating the LD50 requirements in the codified potency testing of veterinary vaccines containing Leptospira serogroups Icterohaemorrhagiae and Canicola in the United States” (Walker et al., 2018). Validity and disposition requirements submitted to the Center for Veterinary Biologics (CVB) are provided for serials (numbered lots) of commercial product potency tested for serogroups Canicola and Icterohaemorrhagiae in support of the Virus-Serum-Toxin Act (VSTA). Time course data for hamster loss after challenge with various concentrations of Leptospira during codified potency testing are also presented. The dose of Leptospira lethal to 50% of hamsters (LD50) was calculated by the Dragstedt-Behrens method for the in vivo data collected, and the equation is described here.

An enzyme-linked immunosorbent assay (ELISA) procedure was developed to assay the cytopathic and noncytopathic bovine viral diarrhea (BVD) virus strains used in inactivated vaccines licensed by the United States Department of Agriculture. The assay uses a biotin-labeled, staphylococcal protein A purified polyclonal BVD antibody (Bab) from a calf hyperimmuned against NADL, Singer, C24v, New York-1 (NY-1) strains and a field isolate. The Bab recognized the following reference strains of BVD virus: NADL; NY-1; C24v; Singer; and a field isolate. Monoclonal antibodies (Mab) directed against gp48 and gp53 of the Singer strain of BVD could detect only the Singer and the NY-1 strains. None of the Mab tested could differentiate between cytopathic and noncytopathic BVD virus strains. In vaccines containing multiple viral and bacterial components, the Bab was specific for the BVD fraction. Two vaccines not recognized by the Bab differed from the others in the type of adjuvant. The formation of antigen-adjuvant complexes during vaccine production may inhibit the ability of Bab to detect BVD antigens in an ELISA format. This ELISA procedure enables the detection of BVD antigens and demonstrates the potential for in vitro testing of inactivated BVD vaccines in place of the currently required host animal testing.