FIG 6.

Passive transfer of RBD-, S1-, and S2-specific neutralizing MAbs protect against MERS-CoV infection. (A) Groups of 10 human DPP4-transgenic (hDPP4) mice were administered MAb CDC2-C2 (RBD specific), G2 (S1 specific), or G4 (S2 specific) (20) via the intraperitoneal route 1 day prior to challenge with MERS-CoV EMC. hDPP4 mice were challenged intranasally with 10⁶ TCID₅₀ of MERS-CoV (strain EMC/2012). At 3 days postinfection (dpi), four animals were sacrificed and lungs were collected for analyses. The remaining six animals were observed for 28 days for survival. (B) Survival curves of the different groups (6 hDPP4 mice per group). After challenge, hDPP4 mice were euthanized due to the severity of disease signs or at 28 dpi. (C and D) MERS-CoV viral titers in the lower respiratory tract (C) and in the brain (D) of hDPP4 mice at 3 dpi. Mean values ± SD were calculated. The dashed line indicates the cutoff limit of the TCID₅₀ assay.