 This project is designed to assess the efficacy of immunizing women during pregnancy with influenza vaccine on the health of these women during their pregnancy and for 6 months post-partum as well as on the health of their newborn infants during the first 6 months of life. It will be conducted in Sarlahi District in southern Nepal, a rural area where a number of large scale randomized trials have been conducted over the past 20 years. 