Vietnam is the world largest producer of striped catfish (Pangasianodon hypophthalmus). The intensification of striped catfish production has resulted in increased disease outbreaks. Developing a multivalent vaccine for prevention is the optimal option, to achieve this goal requires basic research on monovalent vaccines. The study was carried out to evaluate the effectiveness of monovalent vaccines against diseases caused by A. hydrophila and E. ictaluri bacteria on striped catfish cultured in the Mekong Delta, Vietnam. A total of 65 strains of A. hydrophila and 57 strains of E. ictaluri were isolated in striped catfish farms from the year 207-2020. Screening the highest virulence isolates were performed and the two candidate bacterial isolates: A. hydrophila AH3 and E. ictaluri 37 were selected. Lethal dose 50 (LD50) values of A. hydrophila AH3 and E. ictaluri 37 strains were 4.7x02 CFU/mL and 2.35x05 CFU/mL, respectively. The oil-emulsion form vaccines containing formaline-killed bacteria was developed from these two strains of bacteria and evaluated for effectiveness on striped catfish in the wet-lab. The results showed that the specific antibody response to A. hydrophila of vaccinated fish showed at high levels (level of 6.5) after 20 days post vaccination, then reduced in day 30 (level of 4.5). Whereas, the antibody response to E. ictaluri were also high antibody levels (level of .0) after 0 days post vaccination, but slowly reducing after the day 30 (level of 9.5). In addition, the challenge experiments to evaluate the relative percent survival (RPS%) showed a protection rate of 93.3% in the AH3 vaccine and 80% in the EI37 vaccine.