RBD (S377-662)-Fc protein  Binds to DPP4 receptor  Poly(I:C); Montanide  I.N. or S.C.  BALB/c mice  Elicits MERS-CoV S1- and RBD-specific Abs (IgA, IgG (> 1:104), IgG1, IgG2a, and IgG3) in mice, neutralizing (≥ 1:2.4 × 102) live MERS-CoV (EMC2012 strain)  Induces MERS-CoV S1-specific cellular immune responses (IFN-γ and IL-2) in mice  N/A  Du et al., 2013c; Ma et al., 2014b