In the North Atlantic region, Lumpfish (Cyclopterus lumpus) have been utilized as cleaner fish to biocontrol sea-lice (Lepeophtheirus salmonis) infestations in Atlantic salmon (Salmo salar) farms. Previous studies showed that naïve lumpfish are highly susceptible to Aeromonas salmonicida infection and commercial vaccines are ineffective against A. salmonicida J233 hiper-virulent strain. Here, we evaluate the immune protective effect of A. salmonicida outer membrane proteins (OMPs) and bacterins in lumpfish with and without the Vap A layer (A+/A-). Triplicated groups of pit-tagged lumpfish (11 ± 2 g; n=40 per group) were intraperitoneally (ip) injected with outer membrane proteins from A+ and A- strains of A. salmonicida grown under iron-rich (OMPs) and iron-limited condition (IROMPs), and formalin-killed A+ and A- A. salmonicida bacterins. CARBIGEN™, a terminally-sterilized, carbomer-based (Carbopol 934P) adjuvant was used with the vaccine formulation. Blood samples were collected every two-week post-injection for the enzyme-linked immune sorbent assay (ELISA), and spleen samples were collected at six-week post-injection for a qPCR assay. Immunized fish were ip challenged with A. salmonicida J223 with 104 cells per dose at eight weeks post-immunization. All immunized fish had a similar mortality tendency to the non-immunized control fish. Most of the control and vaccinated fish died within two weeks post-challenge. Therefore, our results demonstrate that OMPs, IROMPs, and formalin killed bacterial cells of A+/A- A. salmonicida does not confer immune protection to lumpfish against A. salmonicida J223. These finding lead to the hypothesis that the inactivated A. salmonicida J223 does not trigger memory immune responses and confer protection to lumpfish. To further investigate, ELISA and qPCR analyses were conducted. Interestingly, ELISA results demonstrate that formalin killed A. salmonicida J223 bacterins either in presence or absence of Vap A layer does not increse IgM titers. Instead, it downregulates genes encoding IgM, MHC-II, and CD4, which indicated immune suppression. Therefore, our results support the hypothesis and give us a demonstration of the ineffectivity of many commercial and in-house vaccine against A. salmonicida J223. This study has provided a valuable resource and novel insight into the immune suppression effect caused by the A. salmonicida J223 strain.