ISAV Vaccination Strategies: New Research

Infectious Salmon Anemia Virus (ISAV) management has been an ongoing challenge for salmon farmers in Atlantic Canada.  Successful vaccination programs remain an integral component of ISAV management.  To better understand some of the complexities associated with ISAV in PEI.  vaccination, PHARMAQ recently partnered with ONDA to carry out an ISAV vaccination trial

Why focus on ISAV now?

ISAV remains one of the most significant viral threats to Atlantic salmon aquaculture. The virus, a member of the Orthomyxoviridae family, can cause severe disease outbreaks with high mortality. ISAV is a reportable disease in Canada, and outbreaks trigger strict management measures, including quarantines and culling.

A Brief History of ISAV in Eastern Canada

ISAV first emerged in the late 1990s in New Brunswick, rapidly becoming a major challenge for salmon farmers in the Bay of Fundy and beyond. Early outbreaks led to widespread losses and prompted the development of rigorous biosecurity, surveillance, and vaccination programs. Over the years, both North American and European genotypes of ISAV have been detected in the region. Continuous improvements in management and vaccine technology have helped reduce the impact, but ISAV remains a persistent concern for the industry.

What does the new study show?

Study design:
Researchers compared the efficacy of ALPHA JECT micro® 7 ISA—PHARMAQ’s ISAV vaccine—against both North American and European ISAV strains. Four treatment groups were tested:
- Control (PBS)
- ALPHA JECT micro® 7 ISA alone
- ALPHA JECT micro® 7 ISA with a booster (another commercial ISA vaccine)
- Simultaneous injection of two multivalent ISA vaccines

Key Findings

• Single vaccination with ALPHA JECT micro® 7 ISA provided robust protection against both ISAV strains.
  - Boosting or combining vaccines did not improve efficacy—in fact, simultaneous vaccination reduced protection against the European strain.
  - No significant drawbacks were observed in fish growth, vaccine reactions, or smolt readiness across regimens.

Results

[Fig. 1-Overall survival of vaccinates: North American ISAv challenge]

[Fig. 2-Overall survival of vaccinates: European ISAv challenge]

What does this mean for your farm?

- Simple, effective protocols: ALPHA JECT micro® 7 ISA alone is highly effective and safe for the fish—no need for complex vaccine schedules.
- Streamlined operations: Fewer injections mean less handling stress and better fish welfare.
- Continued vigilance: ISAV remains a threat; surveillance and biosecurity are still essential.

Next steps

For advice on ISAV vaccination or to discuss how these findings based on recent research from PHARMAQ and ONDA fit your farm’s needs, reach out to your local PHARMAQ representative. We’re here to help you protect your fish and your business.