Viral protein glycosylation represents a successful strategy employed by the parasite to take advantage of host-cell machinery for modification of its own
proteins. The resulting
glycans have unneglectable roles in
viral infection and immune response. The spike (S)
protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which presents on the surface of matured virion and mediates viral entry into the host, also undergoes extensive glycosylation to shield it from the human defense system. It is believed that the ongoing
COVID-19 pandemic with more than 90,000,000
infections and 1,900,000 deaths is partly due to its successful glycosylation strategy. On the other hand, while
glycan patches on S
protein have been reported to shield the host immune response by masking "nonself" viral
peptides with "self-
glycans," the
epitopes are also important in eliciting
neutralizing antibodies. In this review, we will summarize the roles of S
protein glycans in mediating
virus-receptor interactions, and in antibody production, as well as indications for
vaccine development.