Oral immunization with plant-based vaccine induces a protective response against Infectious bursal disease

LUCERO MARIA SOLEDAD; CHIMENO ZOTH S.; JATON, JUAN; GRAVISACO MARIA JOSE; PINTO SILVINA; RICHETTA MATÍAS; BERINSTEIN ANALIA; EVANGELINA GOMEZ

Frontiers in Plant Science, section Plant Biotechnology

Frontiers Media S.A

Lugar: Lousanne; Año: 2021 vol. 12

1664-462X

Infectious bursal disease virus (IBDV) is the etiological agent of an immunosuppressiveand highly contagious disease that affects young birds causing important economiclosses in the poultry industry worldwide. We have previously developed a plant-basedvaccine candidate for infectious bursal disease (IBD) that is able to protect againstinfection with IBDV when administered through intramuscular (im) route. Given that oralvaccination is non-invasive and stimulates the immunity of the mucosal gastrointestinalsurface, the initial site of contact and entry of IBDV, the aim of this work was tostudy if our immunogen was also able to elicit a protective immune response whenorally administered. We demonstrated that 85% of the animals that received two oraldoses of the vaccine formulation and all animals that were orally boosted after an imprime scheme developed virus neutralizing antibodies and were protected against IBDVinfection, evidenced by the bursa/body weight (BB) ratio, absence of T-cell infiltration,and low viral load in bursa. Although mild to moderate bursal damage was observedin some of these animals, these lesions were not as severe as the ones observed inchallenged control groups, which also presented signs of acute inflammation, bursalatrophy, T-cell infiltration, and absence of viral clearance. These results show thattwo immunizations with our recombinant immunogen are able to induce a specificand protective immune response in chicken against IBDV when orally administeredin a prime/boost scheme or when the oral boost follows an im prime scheme. Inconclusion, our oral plant-based vaccine candidate could represent a viable alternativeto conventional vaccines and is of great interest to the poultry industry.