Ralph Tripp at the University of Georgia in the U.S. will identify genes that, when inhibited, enhance viral replication in the host cell lines used in the manufacture of vaccines in order to reduce the cost of vaccine production. In Phase I, he performed RNA interference screens to identify 21 host genes that, when inhibited, could enhance poliovirus replication and thereby vaccine production. In Phase II, Tripp will broaden his approach to vaccine production against rotaviruses, which cause substantial childhood mortality particularly in developing countries. He will perform a high-throughput RNA interference screen to identify genes that significantly influence viral replication. These will be used to generate a stable gene knockout cell line to test for increased rotavirus production.