4.4 Membrane protein (M)
M protein is the most abundant and highly conserved trans-membrane glycoprotein on the surface of SARS-CoV involved in virus assembly (Neuman et al., 2011). SARS-CoV M protein-derived peptides (M-131 and M-132-161), identified in sera of convalescent-phase SARS patients, have good immunogenicity to induce high titer of specific IgG antibody response in immunized rabbits (He et al., 2005a). The full length M protein has been reported to elicit VN antibodies efficiently in SARS patients upon immunization (Pang et al., 2004). The T cell epitope cluster containing domain of M protein has been reported to elicit a strong cellular immune response (Liu et al., 2010). Though, this protein has not been investigated much for its protective efficacy against SARS-CoV infection, the above factors suggest its potential as a possible vaccine candidate against SARS-CoV-2.