Results indicated that the modified-live virus vaccine induced a strong protective immune response in young calves, even when plasma concentrations of maternal antibody were high. In addition, all vaccinated calves were protected against viral shedding, whereas control calves vaccinated with the sham vaccine shed virus for an extended period of time.

No abstract

Results provided evidence that a pentavalent Leptospira vaccine containing L interrogans serovar hardjo type hardjoprajitno can provide protection against challenge with L borgpetersenii serovar hardjo type hardjo-bovis strain 203. It is important to demonstrate cross-protection that is vaccine specific against disease-causing strains of organisms that are prevalent under field conditions.

Results indicated that an inactivated BHV-1 vaccine can protect against abortion resulting from a substantial challenge infection, with efficacy similar to that of modified-live BHV-1 vaccines.

The vaccine administered to calves at 1 month of age prevented leptospire colonization of kidney and reproductive system tissue and significantly reduced urine shedding following challenge 12 months after vaccination. This vaccine provides an opportunity to protect calves at an early age from becoming infected and ultimately from becoming an LHB reservoir.