A novel Edwardsiella ictaluri E-ict-VL33 strain, a vaccine derived from the novel Edwardsiella ictaluri E-ict-VL33 strain, especially in immersion form and oral form, and a method for protecting fishes from the infection of Edwardsiella ictaluri, especially catfish, the method including a primary immersion immunization using immersion vaccine, and after an appropriate period, boosting by oral vaccination, resulting in a strong and long-lasting immunity for fishes.
