The Effect of Chlorella vulgaris Recombinant Protein-Based Nanovaccine Formulated with Silver Nanoparticles Against Viral Nervous Necrosis on Hematological of Hybrid Grouper

The hybrid grouper (Epinephelus fuscoguttatus × Epinephelus lanceolatus), a fast-growing and high-demand aquaculture species in Indonesia, faces significant challenges from pathogen-induced diseases particularly Viral Nervous Necrosis (VNN) despite the country’s position as the world’s third-largest grouper producer. Silver nanoparticles (AgNPs) are promising antiviral and antimicrobial agents in aquaculture, offering immune-boosting and pathogen-fighting benefits, though their excessive use poses risks of cytotoxicity, hematological disruption, and reduced fish health. This study investigated the effects of a recombinant nanovaccine containing silver nanoparticles (AgNPs) on the hematological profile and survival performance of the hybrid grouper challenged with VNN. Fish were vaccinated with varying doses of AgNPs (33, 66, 112µL), followed by viral exposure, and observed over a 56-day period.  The administration of AgNP-based recombinant nanovaccine in the hybrid grouper resulted in significant improvements in survival (85%) and Relative Percentage Survival (76%) at the 33µL dose (T1), which also showed optimal hematological responses, including hematocrit (27.33%), monocytes (19.1%), and lymphocytes (78.3%). While platelet levels were the highest at the 112µL dose (T3), overall findings indicate that the 33µL dose was the most effective in enhancing immune response and physiological health without inducing toxicity. These results highlight the potential of low-dose AgNP nanovaccines as a promising immunostimulant in marine aquaculture, offering a promising alternative strategy for disease management in aquaculture