Motile aeromonad septicaemia (MAS) mostly caused by Aeromonas hydrophila is a disease of high economic impact in freshwater organism. This study examined the seroconversion and seroprotection of formalinised local isolates of Aeromonas hydrophila in the Clarias gariepinus administered via different routes. Highly virulent Aeromonas hydrophila was treated with 40v/v formalin for 24 h. Bacterin was suspended to 0.5 McFarland standard and utilized to immunize Clarias gariepinus of 400±20 g in three groups with 50 samples each via three routes of administration. Antibody measurement taken at regular intervals before and after vaccination revealed a significantly higher antibody values in all routes compared to the control and difference was noticed at all intervals. Relative percent survival was 71.43, 62.86 and 57.14 intraperitoneal, intramuscular and immersion routes, respectively. Correlation analysis established a strong and direct relationship in the antibody generation through route of administration and efficacy of vaccine. This local vaccine was able to confer a high degree of immunity on Clarias gariepinus and can therefore be used to vaccinate against MAS.

Abstract
INTRODUCTION
METHODS
    Bacterial strain
    Preparation of vaccines
    Experimental Set-up
    Fish vaccination
    Collection of blood samples
    ELISA Protocol
    Challenge test
    Experimental Set-up
RESULTS
    Histological changes and gross lesions
DISCUSSION
REFERENCES

• Saka Babatunde Akeem(Department of Veterinary Public Health and Preventive Medicine, University of Ibadan) Corresponding Author.
• Adeyemo Olanike Kudirat(Department of Veterinary Public Health and Preventive Medicine, University of Ibadan)
• Odeniyi Olubusola Ayoola(Department of Microbiology, University of Ibadan)
• Alarape Selim Adewale(Department of Veterinary Public Health and Preventive Medicine, University of Ibadan)
• Odeseye Adebola Olayemi(Nigerian Institute of Science Laboratory Technology Ibadan)