“…Since then, interest in phage therapy in different aquatic species has gained a lot of interest, among others to control columnaris disease, bacterial cold water disease, edwardsiellosis, enteric septicaemia of catfish, vibriosis, furunculosis, Pseudomonas plecoglossicida infection, Pseudomonas aeruginosa infection, streptococcosis, lactococcosis (Choudhury, Tharabenahalli Nagaraju, Gita, Paria, & Parhi, ), A. hydrophila and P. fluorescens infection (Schulz, Robak, Dastych, & Siwicki, ) and others. More and more often, it is mentioned that phages also directly affect immunity, but most of the work concerns mammalian organisms, in particular humans (Van Belleghem, Dąbrowska, Vaneechoutte, Barr, & Bollyky, ; Dąbrowska, ; Górski et al, , ). There is little data confirming impact of phages on fish immune system.…”