Measles: An aerosolized vaccine for measles was developed in Mexico and has been used on more than 4 million children since 1980. Aerosolized vaccines have the advantages of not requiring injection and not causing injection-associated injuries. Despite these advantages, data on the efficacy of the aerosolized vaccines have been inconsistent. A large randomized controlled study was conducted in India to compare the immune response to measles between children who received a subcutaneous injection and those who received the aerosolized vaccine. The primary outcome was measured 91 days after the treatments. Among the 785 children receiving the subcutaneous injection, 743 developed an immune response, while among the 775 children receiving the aerosolized vaccine, 662 developed an immune response. The proportion of subjects experiencing the primary outcome was computed for both the aerosol and injection groups. Additionally, the suitability of using a large-sample confidence interval for comparing the proportion of children who developed an immune response in the aerosol and injection groups was discussed. Finally, a 95% confidence interval for the difference between the proportion of children in the aerosol and injection groups who experienced the primary outcome was provided.