The global shrimp aquaculture industry is worth in excess of US $10 billion annually, but continues to be beset by endemic viral diseases. The ability to vaccinate shrimp and other crustaceans against specific viral diseases is therefore of global economic and biosecurity significance. Higher vertebrates, including humans, have an adaptive immunity that enables them to specifically "remember" exposure to pathogens and respond with increased efficiency on subsequent encounters, forming the basis of vaccination. It has been widely accepted that invertebrates do not have such a system. However, there is mounting evidence for specific immune memory in crustaceans, including shrimp. This review explores the phenomenon of antiviral immunity in shrimp and explores this paradigm shift in the context of potential vaccination strategies for shrimp aquaculture.