TRANSCRIPTOME PROFILING OF IMMUNE RESPONSE OF VACCINATED ATLANTIC SALMON TO SINGLE INFECTION WITH Piscirickettsia salmonis AND COINFECTION WITH Caligus rogercresseyi

Vaccines have been the main strategy to prevent and control Piscirickettsiosis outbreaks in Chilean salmon farming. However, immunological mechanisms involved in the response against Piscirickettsia salmonis in immunized Atlantic salmon are unknown. This study analyzed the head kidney transcriptomic profile through mRNA-seq of moribund and surviving fish, unvaccinated and vaccinated with two commercial vaccines, and challenged with a single infection with P. salmonis and a coinfection with sea lice Caligus rogercresseyi under? mimic field conditions. Coinfection was a highly detrimental phenomenon for fish, with a low percentage of live fish at the end of the trial, regardless of whether they were vaccinated or not (