Clone Purification, Characterization and Standardization of LaSota Strain for Developing a Live Vaccine against Newcastle Disease Virus

Abstract

Background and Aims: Newcastle disease (ND) is one of the most serious illnesses of chickens. Live vaccines are widely used to prevent chicken from the disease all over the world. Materials and Methods: To access the effective and potentiate ND vaccine, a homogenous subpopulation from LaSota strain was selected following cultivation of the virus on primary chicken embryofibroblast (CEF) cells. Pathogenicity indices and molecular characterization of a several plaques at 3rd passage were analyzed and then the selected clone was candidate for vaccine development. ND vaccine was prepared according to the standard protocols. Results: The immunogenicity of the live vaccine was examined in specific pathogen free (SPF) and commercial chickens. The geometric mean hemagglutination-inhibition (HI) titers induced in chickens vaccinated with the cloned vaccine were not significantly differ than those induced in chickens vaccinated with the similar ND clone vaccine. Conclusion: Efficacy of the ND vaccine was estimated against the virus challenge. The results indicate that the cloned vaccine could confer a complete protection against NDV.

Evaluation of the Newcastle disease virus genotype VII–mismatched vaccines in SPF chickens: A challenge efficacy study

“…This may explain variations in the immunogenicity of vaccinal strains ( Spalatin & Hanson, 1976 ). Cloned vaccines like Clone12.IR, derived from the La Sota strain, offers a uniform subpopulation with consistent genetic information, inducing high and reproducible immunity with fewer post-vaccinal reactions compared to mixed virus strain vaccines ( Ebrahimi et al, 2014 ). This also may explain the observed longer survivability time and higher odds ratio for protection in La Sota and Colne12.IR compared to the B1 vaccinal strains.…”

The Tween 80 Toxicity in Chicken Embryos and Effect on the Kinetics of Newcastle Disease Virus Replication

“…The allantoic cavity of the embryos is a widely used substrate for viral replications [12,13]. As mentioned earlier, NDV utilizes the lipid raft domains to enter the host cells during the initial stages and the subsequent replications [26][27][28].…”

“…A series of ten-fold dilutions of Clone12-IR strain of NDV [13], 10 -6 through 10 -10 was made by serially mixing 0.5 ml of the virus with 4.5 ml of sterile PBS at pH 7.2. The 9-day-old embryonated SPF eggs were inoculated with each 10 -6 -10 -10 dilution of NDV.…”