Comparative study of antibody titers produced against two BHK rabies vaccines in field trial experimental condition in dogs by RFFIT

ABSTRACT

Rabies is acutely fatal encephalitis caused by a neurotropic virus. This virus belongs to the family of Rhabdoviridae and genus of Lyssavirus. The virus is almost always transmitted to human through infected mammalian saliva. Rabies is inoculated to a wound by an infected animal bite. Since infection is established in the CNS, the outcome is almost always fatal. According to the outstanding role of vaccination against rabies in animals, as well as post-exposure treatment regimen in human, production of cell-cultured rabies vaccine is the most common interest of researchers. Two BHK-rabies vaccines, one made in the Pasteur Institute of Iran and two in Schering-Plough Animal Health of Madrid, Spain have been tested on 12 dogs divided into two groups. Sera were taken monthly over 18 months. To evaluate the titer of the rabies-neutralizing antibody, these sera were analyzed by the rapid fluorescence focus inhibition test [RFFIT] in the end of each month. Both study groups showed a sufficient immunogenic response without any significant difference at least one year after vaccination. With respect to the effective immunization of rabies vaccines, their annual injections would be sufficient. According to the results, at the end of the study [18th month] serum titer in only one dog [No.7] was less than protective level. Two animals in group one [No.2 and No. 5] also had serum titers less than protective level. Mean of post vaccination antibody titer were not different in either groups [P=0.35]