Table 1.

Information and characteristics of SARS-CoV-2 mutant strains.

WHO label	Pango lineage	GISAID clade/lineage	Nextstrain clade	Earliest documented samples	Date of designation	Characteristic
Alpha	B.1.1.7	GRY (formerly GR/501Y.V1)	201/S:501Y.V1	United Kingdom, Sep-2020	18-Dec-2020	It can more easily bind to cellular receptors, thereby increasing infectivity and infection rates. The rate of transmission is very fast, 50-70% more contagious than the original SARS-CoV-2 and has reached over 50 countries [31].
Beta	B.1.351	GH/501Y.V2	20H/S:501Y.V2	South Africa, May-2020	18-Dec-2020	It has the characteristics of escaping immune system and strong binding with ACE2 receptor, which can reduce the effectiveness of vaccine protection. Even after vaccination, people may be infected, and it also makes some medical treatments difficult. It has spread to 20 countries [32].
Delta	B.1.617.2	G/452R.V3	21A/S:478K	India, Oct-2020	VOI: 4-Apr-2021 VOC: 11-May-2021	The virulence is significantly increased, and it can better bind to ACE2 and has immune escape, resulting in increased infectivity, which was 80% higher than that of the Alpha [33].
Gamma	P.1	GR/501Y.V3	20J/S:501Y.V3	Brazil, Nov-2020	11-Jan-2021	It has a new and stronger ACE binding site which helps the virus escape the immune system, making it more infectious, and it can reduce the protective effectiveness of vaccines and drug treatments, which is likely to cause more harm. And it has a high rate of transmission, as has been found in Japan, Germany and some other countries [34].