<i>S</i>. <i>aureus</i> isolate P skin infection.

<p>^a Mann-Whitney U test</p><p>^b Wilcoxon signed ranks test</p><p><i>* P</i> < 0.002</p><p>Median fluorescence intensity (MFI) values reflecting levels of antigen-specific IgG against 25 <i>S</i>. <i>aureus</i> antigens in sera from mice (n = 10 per group) before skin infection (week 0), after skin infection once (week 2 and week 5), and after skin infection twice (week 5 after first skin infection).