Immunogenicity of the live attenuated (Smithburn) Rift Valley fever vaccine in sheep, goats, cattle, buffaloes and camels

Abstract

In the present study, the humoral immune response developed following vaccination with the live-attenuated (Smithburn) Rift Valley fever (RVF) vaccine in sheep, goats, cattle, buffaloes and camels was investigated. Results showed that, serum neutralizing antibody titers of RVF virus started to appear in the sera of all vaccinated animals with live-attenuated Rift valley fever vaccine after the first week post-vaccination and reached its peak after the third month of vaccination. It persisted to be higher than the acceptable limit of protection (>40) in the sera of sheep and goats in more than 6 months post-vaccination while it declined in the sera of cattle, buffaloes and camels to become lower than the acceptable limit of protection (<40) after the sixth month post-vaccination. On the other hand, the serum neutralizing antibody titers remained negative in the sera of non-vaccinated (control) animals throughout the study. It could be concluded that, the neutralizing antibodies following vaccination of cattle, buffaloes and camels with live attenuated RVF (Smithburn) vaccine was low and of a short duration compared with those in sheep and goats. Hence, it is important to prepare a new vaccine which is safe and gives a high immune response for long period in cattle, buffaloes and camels instead of live attenuated (Smithburn) RVF vaccine to protect these animals species against this disease.

Keywords

• immunogenicity; attenuated; smithburn; fever vaccine; sheep; goats; cattle; buffaloes; camels