In 4-quart Dutch oven, combine 2 cups water, seasoning, shrimp and celery. Cook, uncovered, over medium-high heat for 5 to 8 minutes or until shrimp shells turn pink and shrimp are opaque. Remove shrimp with slotted spoon or tongs; set aside to cool. Whisk together evaporated milk, milk, flour, and anchovy paste; add to liquid in Dutch oven. Cook, uncovered, over medium heat for 10 minutes, stirring occasionally. Meanwhile, peel the shrimp and add to soup. Cook for 1 to 2 minutes or until heated through. Ladle into bowls. Pass Old Bay.