Evaluate the Shedding and Immunogencity of Different Formulations of FluMist in Children 24 to <48 Months of Age

0.2 mL (total dose in both nostrils) on Days 1 and 28. Each 0.2 mL dose will contain 10\^7±0.5 FFU of each vaccine strain.

0.2 mL (total dose in both nostrils) on Days 1 and 28. Each 0.2 mL dose will contain 10\^7±0.5 FFU of each vaccine strain.

0.2 mL (total dose in both nostrils) on Days 1 and 28. Each 0.2 mL dose will contain 10\^7±0.5 FFU of each vaccine strain.