By studying the most suitable storange conditions that maintains the efficacy and stability of improved polyvalent fowl cholera vaccine for poultry, it is
evident that all the three batches that stored at 4 °C or 28-30 °C after 30, 60, or 90 days of storage start to induce a systemic humoral antibodies after fifteen days postvaccination. The geometric mean titres (GMT) of specific anti Pasteurella multocida antibodies increase till reach a maximum GMT on the 45th postvaccination day. There is a marked decreases of GMT in speccific anti Pasteurella multocida antibodies in batches that stored at 28 30°C than those stored at 4°C especially at 30th and 45th day postvaccination. These results is further documented by potency testing in chicken and mice as acceptable protection was noted in chicken vaccinated with avain cholera vaccine stored at 4°C and 28-30°C (at room temperature). The vaccine can induce seroconversion and evoke a protection of 90% at the 6th month of srorage. The protection still gave acceptable protection (65%) at the 15th month of storage. Regarding the physical properties and sterility of examined batches, it was obvious that all batches remaind stable and sterile up to 15 months after the date of manufaeture. In conclusion, the improved polyvalent fowl cholera vaccine for poultry can be used safely and effectively up to 15 months post manufacture date when stored at 4 °C.