Limited systemic and mucosal B cell responses in aged monkeys infected with SARS-CoV. (A) SARS-CoV neutralizing antibodies were measured in sera of aged and juvenile animals over the infection time course. Graphs represent average values (+/−SE). For day 0, aged n = 10, juvenile n = 12. For day 5 and 10 post infection n = 5 for aged and n = 6 for juvenile. ****p < 0.0001 for age and time post infection (d.p.i.) as indicated in the graph by 2-way ANOVA with a Bonferroni post-test, p < 0.05. (B-C) Anti-SARS-CoV spike protein specific IgG (B) and IgA (C) were measured in lung tissue homogenates by ELISA. Graphs represent average values, n = 5 for aged and n = 6 for juvenile (+/−SE). *p < 0.05 in unpaired student T-test comparing juvenile and aged animals at the time points indicated by the horizontal bar.