Preparation and evaluation of haemorrhagic septicaemia oil adjuvanted vaccine with a new ready to use oil adjuvant for cattle and buffaloes

Haemorrhagic Septicaemia (HS) caused by Pasteurella multocida serotype B:2 is an economically important disease of cattle and buffaloes, which causes heavy economic losses due to sudden death of animals in developing countries like Pakistan. In this country, animals were being vaccinated by alum (adjuvant) precipitated vaccine twice a year. Immunity induced through this prophylactic measure lasts for 3 to 4 months only, which reflect an un-protective state of the animals between two vaccinations. A new HS oil based vaccine has been developed by adding an adjuvant Montanide ISA-50V2 with the ratio of 1:1. The bacterial dry weight has been adjusted to 2 mg/ml which results in to reduction of dose per animal from 5 ml (alum precipitated) to 2 ml. The addition of enrichments and aeration (sparging and vortexing) has resulted in dense bacterial growth of Pasteurella multocida. The new vaccine has passed sterility, safety and potency tests as per OIE, 2017. This new product has low viscosity and single shot is expected to confer solid immunity against HS for one year. Active Mouse Protection Test, Passive Mouse Protection test and Indirect Haem-Agglutination Tests have been used to evaluate its potency. Properties like easy to inject with no side effects such as swelling at the injection site, have motivated the livestock owners to use this new product to protect their animals against fatal HS disease which will ultimately result in the increased productivity of livestock in Punjab, Pakistan.