Preparation of Tissue Culture Vaccine from Velogenic Viscerotropic Virus Strain of Newcastie Disease Virus

A mammalian tissue c~lture attenuated strain was developed from the locally isolated VVNDV of high immunogenicity to replace the egg propagated vaccinal strains in order to avoid the possibility of introducing egg borne infections to the poultry flocks th3 - Virulence determinatioli of VVNDV strain harvestwas performed every 10 successive passages in MScells.