If we get a positive result for IPNV or SAV on vaccinated fish, we always run a vaccine differentiation analysis in addition. When we perform a vaccine differentiation it means that we can determine if it is a virus or a vaccine component that is detected in the positive samples. We perform differentiation routinely unless the client has reserved against it when ordering.
This is the reason we ask for vaccine information when you are ordering analyses.
PatoGen can perform differentiation for several vaccine components:
- IPNV, ex. ALPHA JECT micro® 6, AQUAVAC® PD7
- SAV, ex. ALPHA JECT micro® 1PD - Patent WO 2020/122734
Avoid contamination of the tissue sample with vaccine from the abdominal cavity
Research carried out by PatoGen indicates a certain risk that residual of vaccines can be detected in fish vaccinated against PDV, IPNV, Yersinia or Flavobacter. The risk decreases in time and is minimized by avoiding direct contact with the vaccine in the internal abdomen. For PDV and IPNV vaccinated fish are distinguished from infected fish based on which virus variant that are detected, while for other agents there are not yet good methods to distinguish vaccinated and infected fish.
When sampling for analysis of IPNV, Yersinia and Flavobacter, contamination of the kidney sample with the vaccine is avoided by taking the sample via the neck. When sampling for analysis of PDV, contamination of the heart sample with vaccine is avoided by taking the sample with an incision in the heart cavity without opening the abdominal cavity.