Dosage and Route: Within an exposed group, subjects will be randomized to receive either hepatitis A vaccine, VAQTA™, or immune globulin (IG) intramuscular (IM). Clinical material will be administered by unblinded study personnel but subjects will not be told which clinical material is being administered. The unblinded personnel will not be involved with any other study procedures for that exposed group. Syringes will be masked to avoid any possible chance at subject unblinding. The dose of VAQTA™ to be used will depend on the subject’s age. Persons 2 to 18 years of age will receive a 25-U dose of VAQTA™ administered intramuscularly in the arm in a 0.5 mL volume. Persons 19 to 40 years of age and less than or equal to 75 kg in weight will receive a 50-U dose of VAQTA™ administered intramuscularly in the arm in a 1.0 mL volume. Persons 19 to 40 years of age and greater than 75 kg in weight will receive a 50-U dose of VAQTA™ (administered as two 25-U doses) administered intramuscularly with 0.5 mL in each arm. Persons 2 to 18 years of age will receive IG in one arm; persons 19 to 40 years of age and less than or equal to 75 kg in weight will receive IG in one arm; and persons 19 to 40 years of age and greater than 75 kg in weight will receive IG with the total dose equally divided between each arm. All persons randomized to receive IG will receive a dose of 0.02 mL/kg of body weight, up to a maximum of 1.5 mL for those less than or equal to 75 kg in weight and 3.0 mL for those greater than 75 kg in weight. All subjects less than or equal to 75 kg will receive 1 injection and only subjects 19 to 40 years of age and greater than 75 kg will receive 2 injections.