The use of live vaccines in poultry and other food animals to control economically significant livestock diseases is associated with many risks to the animals and the environment. Inactivated and subunit vaccines are relatively safer alternatives to the currently live vaccines used widely in the poultry industry and other farm animals. However, they require potent adjuvants and injection methods of administration for them to be effective. The overall goal of this project is to evaluate the potential of generally regarded as safe (GRAS) microbes (probiotics), to act as immune-enhancing carriers of non-living infectious disease vaccine antigens across the respiratory mucosa (intranasal) in food animals without the need to inject the animals.

Some probiotics strains have been shown to have a free benefit in the host that indicates they can enhance vaccination outcomes. The project aims to screen for probiotic strains that can stimulate desirable innate immune response indicative of improved immunity potential in the avian respiratory mucosa and potentially enhance an immune response to avian inactivated or subunit viral vaccines delivered through the intranasal route. The initial objective is to use molecular, cellular, and immunological methods to characterize the immune effects induced by select probiotics strains in the avian respiratory mucosa after intranasal administration. This will be followed by administering viral inactivated or subunit vaccines together with the identified probiotics intranasally and evaluating viral-specific immune response comparing between chicken receiving vaccines mixed with and without probiotics.

This project’s primary goal is to evaluate the potential of select probiotic strains to act as adjuvants or carriers of infectious disease vaccine antigens across the respiratory mucosa surfaces in poultry. Future studies will determine the probiotics’ ability to act as broad vaccine adjuvants to contagious diseases of farm animals.

The benefits of antibiotics in animal health have been well documented, especially as alternatives to antibiotcpromoters and in enhancing immunity to infectious diseases. The immunomodulating potential is a field that remains to be explored, especially as adjuvants to boost immunity in farm animals during vaccinations. This project is investigating the possibility of probiotics increasing the treatment outcome in animals, primarily when used with killed, inactivated, and subunit vaccines. A demonstrated adjuvant potential with non-living vaccine antigens especially beneficial as it reduces the need for the use of live vaccine material, which potentially has inherent safety risks.