For a pretty touch, tie a strip of blanched scallion green around each packet.
Cook shrimp in boiling water just until curled and opaque in the center, 1 to 2 minutes. Drain and refresh under cold running water. Transfer to a cutting board to cool, then chop.
Combine the shrimp with sprouts, scallions, mint, fish sauce and lime juice in a bowl. Soak 6 of the rice papers in a large bowl of very warm water until they are softened, about 30 seconds. Place them in a single layer on a clean dishtowel. Put a heaping tablespoonful of shrimp filling in the center of each rice paper and fold over all four edges to form a square, slightly flat packet. Repeat with the remaining rice papers and filling. Serve with a small bowl of Rice-Wine Vinegar Sauce for dipping.
Rice-Wine Vinegar Sauce
2 starch, 1 1/2 lean meat