Compositions and methods of protecting aquatic invertebrates from disease is shown. In one embodiment, dsRNA or antisense RNA to a nucleic acid molecule of the disease-causing microorganism is prepared and delivered to the animal. In another embodiment, a nucleic acid molecule of the disease-causing microorganism is delivered to the animal. In another embodiment, the RNA or nucleic acid molecule is delivered to the animal by replicon particle. In a further embodiment, the protective molecule is delivered to the digestive tract of the animal. Protection from disease is obtained.