Inactivated Newcastle disease virus (NDV) vaccines were prepared using paraffin oil, paraffin oil and
aluminum stearate (Al.St.) and Montanide oil ISA 71VG as adjuvants. All experiments gave the priority
to the inactivated NDV vaccines with paraffin oil adjuvant and Al.St. 4- 5 mg/dose including stability
(drop test, centrifugation and real time test) and viscosity (dynamic and relative) over NDV vaccine
adjuvant with paraffin oil alone that showed reduced stability, however NDV vaccine with paraffin oil
and Al.St. 6mg/dose and 7mg/dose showed high values of viscosity indicating hard injectability. Chicks
vaccinated with inactivated NDV vaccines with paraffin oil adjuvant and Al.St. (4, 5, 6 and 7 mg/dose)
gave higher cell mediated immune response (lymphocyte blastogenesis and macrophage activity),
humoral immune responses (using haemagglutination inhibition test) and 100% protection upon
challenge experiment in comparison to that vaccinated with NDV vaccine with paraffin oil adjuvant
alone that showed 93.3% and 86.66% protection for vaccines used immediately after preparation and
the others used after one year of storage at 4°C, respectively. Chicks vaccinated with NDV vaccines
with paraffin oil adjuvant and Al.St showed slightly lower values of both cellular and humoral immune
responses than that of NDV vaccine adjuvant with Montanide ™ ISA 71VG. In conclusion, inactivated
NDV vaccine prepared with paraffin oil adjuvant and aluminum stearate (4 mg/dose and 5 mg/dose)
were superior for that adjuvant on paraffin oil alone, as they improved stability and potency of the
vaccine, and were with the same quality to that of NDV vaccine adjuvant on the imported Montanide
ISA 71VG.