IVIT   27842
INSTITUTO DE VIROLOGIA E INNOVACIONES TECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Field trial of a BLV attenuated vaccine under productive conditions
Autor/es:
PETERSEN, M; ABDALA, A; JACQUES, JR; TRONO, K; FRANCO, L; ALVAREZ, I; SAFARI, R; SUAREZ ARCHILLA, G; CALVINHO, L; RUIZ, V; WILLEMS, L
Lugar:
Lima
Reunión:
Conferencia; 19th International Conference on Human Retrovirology HTLV and Related Viruses; 2019
Resumen:
- IntroductionBovine leukemia virus (BLV) is highly endemic in intensive dairy productive areas where fatal lymphosarcoma kills around 10% of infected cattle each year. No treatment or vaccine is still available. Using reverse genetics, we have developed a BLV attenuated strain that replicates at reduced rates and that induces a strong immune response able to protect against wild type virus challenge. - ObjectivesWith the purpose to reduce BLV prevalence, we are conducting a large trial under field conditions in a dairy facility under the supervision of animal health authorities. The objectives are to evaluate protection against wild type BLV and safety (transmission between animals, viral recombination, disease onset).- MethodsA cohort study was designed according to natural BLV dynamics assumptions. Ninety-nine young female cattle were enrolled, where 28 were vaccinated with the attenuated strain. Serological reactivity, provirus identification and proviral loads were followed up at different time points. - ResultsThe vaccinated group has completed 15 months follow-up without evidence of wild type infection or transmission of the vaccine strain to controls. In comparison with natural infected cattle, proviral loads in the vaccinated group were extremely low or even undetectable. Serology in vaccinated animals showed a natural profile of BLV infection. No signs of tumors were detected.- ConclusionThe intermediate time point within the field trial suggests that BLV vaccination strategy using the attenuated strain is effective and safe to protect against BLV.