Does infection with piscine reovirus (PRV) affect how salmon respond to challenge with and vaccination against infectious hematopoietic necrosis virus (IHNV)?



Piscine Reovirus (PRV) is a newly described double stranded RNA virus belonging to the family Reoviridae. PRV is common in wild and farmed salmon in BC (Marty et al. 2014) and likely establishes long term infections in its hosts. It is inevitable that mixed infections of PRV and known pathogens will occur. One pathogen that is in the same geographical area with PRV is the infectious hematopoietic necrosis virus (IHNV). IHNV occurs naturally in the waters of the Pacific Northwest and with the appropriate virus strain, host condition, and environmental parameters, IHNV can cause an acute disease (IHN) in all five species of Pacific salmon, Atlantic salmon, and Rainbow trout (Oncorhynchus mykiss). Despite the widespread use of the IHNV vaccine in the BC salmon aquaculture industry, little is known concerning the effectiveness of the vaccine when administered in asymptomatic fish infected with other viruses.

This project sets out to examine the consequences of viral co-infections of Piscine Reovirus (PRV) and Infectious Hematopoietic Necrosis Virus (IHNV) in Atlantic and Sockeye salmon. The study will address how Atlantic salmon and Sockeye salmon hosts, infected with viruses with no or low pathogenic effect, respond to vaccination against, and to challenge with other viruses. Challenge trials will be used to examine IHN disease progression in naïve (never before infected) and IHNV vaccinated non-PRV (control), and PRV-infected Atlantic salmon. An IHNV challenge trial will also be conducted with non-PRV (control), and PRV-infected Sockeye salmon that are naïve with respect to IHNV. These challenge trials will be used to determine if there are differences between groups in morbidity associated with IHNV challenge, and to generate biological samples for gene and microRNA expression studies. This research will help to determine what, if any, additional risk is posed to wild and/or farmed fish due to changes in their ability to respond to IHNV vaccination and/or to exposure to IHNV, thereby contributing to the knowledge base important for the sustainable management of the salmon aquaculture industry.





Program Name

Program for Aquaculture Regulatory Research (PARR)


2014 - 2017


Pacific: Vancouver Island West Coast

Principal Investigator(s)

Stewart Johnson
Research Scientist, Pacific Biological Station
3190 Hammond Bay Rd., Nanaimo, British Columbia

Kyle Garver
Research Scientist, Pacific Biological Station
3190 Hammond Bay Rd., Nanaimo, British Columbia

Team Member(s)

Jon Richards

Julia Bradshaw

Collaborative Partner(s)

Matthew Rise, Memorial University, Newfoundland

Rune Adnreassen, Oslo and Akershus University College of Applied Sciences