Prime Vaccination with Chitosan-Coated Phipps BCG and Boosting with CFP-PLGA against Tuberculosis in a Goat Model

Abstract

Attempts to improve the immune response and efficacy of vaccines against tuberculosis in cattle, goats, and other animal species have been the focus of research in this field during the last two decades. Improving the vaccine efficacy is essential prior to running long-lasting and expensive field trials. Studies have shown that vaccine protocols utilizing boosting with proteins improve the vaccine efficacy. The use of polymers such as chitosan and PolyLactic-co-Glycolic Acid (PLGA) improves the immune response against different diseases by improving the interaction of antigens with the cellular immune system and modulating the host immune response. This study shows that the prime BCG vaccination, boosted with a culture filtrate protein (CFP), alone or in combination with chitosan and PolyLactic-co-Glycolic Acid (PLGA), have the potential to reduce tuberculosis (TB) dissemination by reducing the number of animals with lesions, the number of lesions per animal, and the size of the lesions in vaccinated animals, compared with those not vaccinated or those vaccinated with BCG alone. The vaccinated groups showed significantly higher Interferon-γ levels in the blood compared to the control, nonvaccinated group after vaccination, after boosting, and after the challenge with the wild-type Mycobacterium bovis strain.

Vaccination Strategies in a Potential Use of the Vaccine against Bovine Tuberculosis in Infected Herds

“…The BCG strains most frequently used experimentally have been the Danish [ 42 , 48 , 49 , 70 , 80 ], the Pasteur [ 31 , 40 , 67 , 76 ], the Tokyo [ 41 , 81 ], and the Russian [ 50 , 61 ]. Another strain used less frequently that has shown efficacy similar to that of the previous strains is the Phipps [ 46 , 66 , 82 , 83 ]. In a study in mice where ten vaccine strains were tested, Phipps was the one that provided the best results against the number of colony-forming units (CFU) and pathological damage in the lung after a challenge with a field strain of Mycobacterium tuberculosis [ 84 ].…”