Effect of Freeze-Drying on I.L.T and I. B. Viral Vaccines

In the present study, dealing with the effect of freeze-drying on infectious laryngotracheitis and infectious bronchitis viral vaccines using different stabilizers and lyophilizer temperature. ePreparation of IBV and ILTV vaccines with different stabilizelaryngotracheitis vaccines at - 60°C to +20°C - 55°C to +30°C- 40°C to +40°Ce Vaccine titrations referred that starch-peptone stabilizer andskimmed milk (20%), gave the highest titre, 106.5°, 106.17 for IBVand] 05.5°, ] 05.30 for IL T at -60°C to +20°C, respectively.eSterility test of liquid and lyophilized vaccines revealed freedomfrom bacterial, fungal and mycoplasmal contamination . Suitable pH for infectious bronchitis virus was 7.8 which gavehighest titre 106.5 and for infectious laryngotracheitis virus rangedbetween 7.0-7.2, which gave highest titre 105.5 Iml. -Safety test for infectious bronchitis and infectiouslaryngotracheitis vaccinal batches were considered satisfactory . • Virulence of IL TV and IBV vaccines were not reversion with no symptoms.