Real time PCR: a rapid tool for potency estimation of live attenuated camelpox and buffalopox vaccines

In the present study, SYBR Green and TaqMan real time PCRs (rt-PCR) based on the C18L gene (encodes ankyrin repeat protein) of camelpox (CMLV) and buffalopox viruses (BPXV) were, respectively employed for potency evaluation of live attenuated camelpox and buffalopox vaccines. Cells infected with the respective vaccine viruses were harvested at critical time points and subjected to respective PCRs. The critical time points of harvests for CMLV and BPXV respectively, were 36 and 30 h post infection and were respectively determined based on maximum slopes of (-3.324) and (-3.321) standard curves. On evaluation of eight batches of camelpox and seven batches of buffalopox vaccines, the results indicated that the titres estimated by respective rt-PCRs were well comparable to the conventional TCID(50) method. The rt-PCR assays were found relatively more sensitive, specific and rapid than end point dilution assay. Thus, they could be used as additional tools for estimation of live CMLV and BPXV particles in camelpox and buffalopox vaccines.