2011 Annual Report 1a.Objectives (from AD-416) Determine if 50,000 IU vitamin A supplementation within 48 hours of birth will (1) improve thymus function; (2) enhance vaccine responses; and (3) decrease incidence of infections. 1b.Approach (from AD-416) A community-based intervention trial in Dhaka, Bangladesh. 3.Progress Report This project was initiated this year to fund field work in Bangladesh to provide vitamin A supplements or placebo at birth to examine the effect on immune function in response to routine vaccination during the first three months of life. Funds have been transferred to ICDDR,B and preparations are being made for enrolling the first subjects later this year. ARS has purchased supplies to be shipped to Bangladesh and has participated in activities to initiate subject recruitment, including preparing research protocols and participating in development of a Data Safety Monitoring Board for the project.