Preparation of inactivated canine distemper vaccine using different inactivators

Abstract

; > Development of environmental, safe and protective vaccines against infectious pathogensremains a challenge. In consequence of its high morbidity and mortality rates caninedistemper is one of the most important diseases of young dogs. The object of the presentstudy is to develop a selected method for preparation of an inactivated canine distempervaccine. This method involved exposure of the virus to different concentrations of binaryethyleneimine (BEI), beta propiolactone (sPL) and hydrogen peroxide (H2O2). Complete virusinactivation was obtained with BEI (0.003M) for 6 hours, sPL (1/5000) for 4 hours and H2O2at a concentration of 3% rapidly inactivated a Vero cell adapted canine distemper virus strainwithin 3 h of exposure without affecting its antigenicity or immunogenicity. The safety,immunogenicity and potency induced in four groups of puppies were evaluated using thethree prepared experimental batches of inactivated canine distemper vaccine. These resultsrevealed that no residual infectious virus was detected in H2O2 inactivated CD vaccine thatproved to be safe and effective when compared with the same virus harvest that inactivatedwith the classical inactivating agents as BEI and βPL. Thus, an alternative inactivationmethod, such as H2O2 is able to maintain the integrity of the virus protein may be essentialfor improving the potency of inactivated canine distemper virus vaccine produced sufficientlevel of antibodies which measured by serum neutralization test (SNT) and was protectedwhen challenged with virulent CD virus strain. These findings reinforce the idea that H2O2can replace BEI and βPL as inactivating agents for canine distemper virus to reduce time andcost of inactivation process.