Intramuscular injection of AgNPs and their stabilizer into Litopenaeus vannamei shrimps is not toxic. Shrimp survival after AgNPs injection was 98.7%. AgNPs injection does not affect metabolic rate or total hemocytes count. After virus infection, shrimps injected with AgNPs survived 80% for 96 h. Proof of principle of AgNPs to act as antiviral against the white spot syndrome virus.