Figure 5.

BCG-induced trained immunity provides protection against IAV, but not SARS-CoV-2

(A) IAV viral load in the BM of C57BL/6J mice (day 3 and 6 post infection with 90 PFU IAV-PR8, n = 3/group).

(B and C) SARS-CoV-2 viral load in the BM of K18-hACE2/J mice (day 3 and 5 post i.t. infection with 4,000 TCID SARS-CoV-2/SB2, n = 3–5/group).

(D) SARS-CoV-2 viral load in the BM of Roborovski hamsters (day 3 post infection with 1 × 10⁵ PFU SARS-CoV-2/RIM-1, n = 3–4/group).

(E) Experimental model of BCG vaccination in humans and infection of blood monocyte-derived macrophages (MDMs) with IAV and SARS-CoV-2/RIM-1 for assessment of cytokine responses.

(F) Expression of IL-1β, TNF-α, CCL2, type I IFNs, and IL-8 in MDMs from human donors before and after BCG vaccination, at 24 h post in vitro IAV-H3N2 or SARS-CoV-2/RIM-1 infection, n = 5/group.

Data are displayed as mean ± SEM. ^∗p < 0.05, ^∗∗p ≤ 0.01, ^∗∗∗p ≤ 0.001, ^∗∗∗∗p ≤ 0.0001 (t test and one-way ANOVA). See also Figure S5.