White Spot Syndrome Virus (WSSV) is a highly aggressive pathogen in shrimp aquaculture, responsible for outbreaks that can cause devastating economic losses worldwide. Infected populations may experience mortality rates exceeding 90% within a matter of days, threatening both the productivity and profitability of shrimp industry. In response to this, the industry and researchers have pursued strategies such as selective breeding for resistance, development of vaccines and antiviral agents, and enhancements in farm management practices. Assessing the success of these approaches depends on having a dependable and standardized challenge model that can reliably produce WSSV infection under controlled conditions.
Many existing WSSV challenge approaches are constrained by the same issue: the onset of mortality is often too rapid and severe, producing acute die-offs that restrict observation windows and complicate the comparison of treatments. To address this, ShrimpVet conducted a dose optimization test in whiteleg shrimp (Penaeus vannamei Boone, 1931) to investigate how varying challenge doses influence mortality dynamics. By carefully modulating the viral dose, we aimed to shift mortality outcomes from uncontrolled acute peaks to more gradual and measurable patterns.
This approach is expected to allow mortality patterns to be shaped in ways more appropriate for experimental evaluation. Instead of abrupt and unpredictable die-offs, this approach will lead toward a WSSV challenge model that balances infection severity with experimental control. Such a model would provide a stronger platform for testing candidate interventions, improving reproducibility between laboratories, and supporting the broader efforts of the aquaculture industry to mitigate the devastating impact of WSSV.
Kaywords: Challenge model, Dose optimization, Mortality patterns, Penaeus vannamei, Shrimp, White Spot Syndrome Virus (WSSV)