Morbidity and mortality from influenza A virus (IAV) infection in gonadectomized (Gdx) male and female C57BL/6 mice. Average (± SEM) change in body mass (a) and rectal temperature (b) from baseline (that is, day 0) following inoculation with 102 50% tissue culture infective dose (TCID50) of mouse-adapted IAV, A/Puerto Rico/8/1934 (PR8). The proportion of Gdx male and female mice surviving PR8 infection during the 21 days post inoculation is shown in (c). Each group consisted of 7-8 mice run in a series of 2 replications. *Significantly different at P < 0.05.