To test whether these memory gDT-2 CD4+ T cells could confer protection against JKD6159-gD infection, naïve mice, or mice primed 21 days earlier with HSV-1, were challenged intranasally with JKD6159-gD and bacterial loads in the lung and nasal tissue were measured from days 1–7 p.i. While we observed no difference in bacterial loads or clearance rate of S. aureus in the nasal tissue between the two cohorts, the HSV-1 primed group more rapidly eradicated S. aureus from the lung (Fig. 3h, i) and this coincided with a rapid influx of CD4+ memory T cells into the airways (Fig S2b). Here, CD4 is linked to infection.