Affiliation: | 1. Department of Biostatistics, University of Washington, Seattle, Washington, U.S.A.;2. Department of Statistics, University of Washington, Seattle, Washington, U.S.A.;3. Department of Biostatistics, Brown University, Providence, Rhode Island, U.S.A.;4. Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, Seattle, Washington, U.S.A. |