Numerous MERS-CoV RBD-based subunit vaccines have been developed and extensively evaluated in available animal models since the emergence of MERS-CoV (Table 2) (Du et al., 2013c; Tai et al., 2017; Zhou et al., 2018). In general, these subunit vaccines have strong immunogenicity and are capable of inducing high neutralizing antibodies and/or protection against MERS-CoV infection (Ma et al., 2014b; Zhang et al., 2016; Tai et al., 2017; Wang Y. et al., 2017). Most subunit vaccines based on the MERS-CoV RBD have been described in detail in a previous review article (Zhou et al., 2019). In this section, we will briefly introduce these RBD-targeting MERS vaccines, and compare their functionality, antigenicity, immunogenicity, and protection against MERS-CoV infection.