Vaccines derived from the Australian V4 strain of Newcastle disease virus, permitted the control of Newcastle disease in village chickens for the first time. The problem of inactivation at environmental temperatures was countered by selecting variant strains with extreme thermostability. The aim of this small project is the production of a vaccine seed that will be suitable to produce vaccine in developing countries. It will be based on an Australian strain of Newcastle disease virus, similar to, but distinct from V4 and selected for heat-resistance, immunogenicity and ability to spread. The seed vaccine will be made available free of charge to laboratories in developing countries wishing to produce their own vaccines for use in village chickens and to Australian vaccine producers should they desire the culture. The final vaccine seed will be freeze-dried or stored frozen. A 1 mL ampoule should contain enough vaccine to inoculate at least 1000 eggs and produce 6 L of working seed.