Studies on the identity ,purity, and safety of komarov seed strain of newcastle disease virus vaccine used in egypt

The present study is concerned Id th the identity, sa£ety and purity of the Komarov seed strain of Newcastledisease virus used in Egypt for the preparation of an intramuscular vaccineThese were determined by plaque techn.ique on chicken embryo fibroblasts which revealed that all plaques produced were identical. Further investi8ations were carried outusing various physical and biological tests to determine the sa£ety of vaccine as a mesogenic virus and its proper--ties as a Newcastle disease virus strain.These tests showed the following results1 - The intracerebral pathogenic inciex for one day cId chicks was 0063.2 - The intravenous pathogenic index for 6 - 8 weeks old chickens was zero.3 - The intracerebral pathogenic index for pigeons was 2024 and the intramuscular index was 0.02.4 - The stability of the haemagglutinin at 56°C was five minutes with DROP in the titre fl’O”ll1 320 to 10.