Comparison of heterosubtypic protection in ferrets and pigs induced by a single-cycle influenza vaccine by Holzer, B, Morgan, S, Matsuoka, Y, Edmans, M, Salguero, F, Everett, H, Brookes, S, Porter, E, Macloughlin, R, Charleston, B, Subbarao, K, Townsend, A, Tchilian, E