Notably, spike (S) protein, which is a viral glycoprotein protruded on the surface of SARS-CoV-2, represents a major target for the design and development of vaccines as it is responsible for the attachment to the host cell surface via binding to the angiotensin-converting enzyme 2 (ACE2), mediating viral entry and, consequently, leading to an infection. Here, ACE2 is linked to infection.