The causative factor of COVID-19, severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2) is continuously mutating.
Interestingly, identified mutations mainly occur in
the spike (S) protein which interacts with the ACE2 receptor
and is cleaved via serine protease TMPRSS2. Some mutated
strains are becoming dominant in various parts of the globe
because of increased transmissibility as well as cell entry efficacy.
Remarkably, the neutralizing activity of monoclonal
antibodies, convalescent sera, and vaccines against the variants
has been reported to be significantly reduced. Therefore, the
efficacy of various monoclonal antibodies therapy and vaccines
against these variants is becoming a great global concern.
We herein summarize the current status of SARS-CoV-
2 with gears shifted towards the recent and most common
genetic variants in relation to transmission, neutralizing activity,
and vaccine efficacy.