Source
Larson L, Hansen J, Ramasami P, et al. Prophylactic use of canine parvovirus monoclonal antibody induces blockade of vaccinal canine parvovirus immunization similar to maternally derived passive immunity. Am J Vet Res. 2025;86(12):ajvr.25.07.0233.xml. doi:10.2460/ajvr.25.07.0233
Research Note
Effectiveness of modified-live viral (MLV) vaccines against canine parvovirus (CPV)-2 depends on the ability of the vaccinal strain to infect the vaccinated dog; antibody-mediated blockade can lead to vaccine failure. CPV monoclonal antibody (CPMA), a chimeric monoclonal antibody for treatment of CPV gastroenteritis in dogs, and maternally derived antibody both function via antibody neutralization of CPV-2. CPMA is conditionally approved by the US Department of Agriculture for prophylactic use to prevent CPV-2 in exposed puppies; however, the degradation profile and duration of passive antibody blockade of active immunization after MLV CPV-2 vaccination have not been characterized.
In this study,a 20 puppies seronegative for CPV-2 were administered CPMA (0.1 mL/kg SC) to evaluate initial CPV-2 antibody titers 24 hours after administration, to verify the CPMA degradation profile, and to determine how long vaccinal CPV-2 virus would be blocked. Results showed a mean passive hemagglutination inhibition titer of 1,674 in the CPMA-treated group and mean degradation half-life of 18.9 days. CPV-2 vaccination resulted in active immunity in 92% of puppies 15 weeks after CPMA treatment and in 100% of puppies after 18 weeks.
These results suggest extending the standard CPV-2 vaccination schedule in puppies that have received CPMA prophylactically, potentially to 17 weeks after CPMA treatment in subclinical puppies exposed to CPV-2 that have littermates definitively diagnosed with CPV; however, CPMA treatment might impact vaccinal responses in litters without known CPV-2 infection and potentially high levels of maternally derived antibody.
a This study was funded entirely by Elanco Animal Health.
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