The disease course in young or aged naïve mice, or primed (with H9N2 or H1N1 virus) aged mice following H7N9 challenge.

<p>The aged females were between 16–18 months at priming and then were challenged about two months later or young (8–10 weeks). Aged matched or young (8–10 weeks) naïve female mice were used for comparisons. (A) The survival ratio and (B) body weight change of the mice after challenge with 10MLD50 of AH/1(H7N9) (data represent mean ± SEM, n = 5–6/group). (C) The body weight change, (D) virus titer in the lung, and (E) the total number of the three-H7N9 virus epitope-specific CTL populations in the BAL samples on d8 after challenge with 1MLD50 of AH/1(H7N9) virus (data represent mean± SEM, n = 3/group). (C, D, E) * p<0.05, t test, indicated group <i>versus</i> the naïve aged group.