| Alpha |
B.1.1.7, B.1.1.7 with E484K mutation and Q lineages |
UK |
September 2020 |
D614G, 69–70 del, N501Y, P681H and E484K |
+29% |
Reduction in the neutralization titers against B.1.1.7 by convalescent sera generated in early strains of SARS-CoV-2 and sera from Pfizer–BioNtech, Moderna, and Oxford-AstraZeneca vaccines |
| Beta |
B.1.351 |
South Africa |
December 2020 |
K417N, E484K, N501Y |
+25% |
B.1.351 is markedly more resistant to neutralization by convalescent plasma (9.4-fold) and sera from individuals who have been vaccinated (10.3–12.4-fold) |
| Gamma |
P.1 |
Brazil |
December 2020 |
K417T, E484K, N501Y |
+38% |
Plasma from individuals previously infected with SARS-CoV-2 had an 8·6 times lower neutralizing capacity against the P.1 isolates and inefficient neutralization of P.1 isolates was seen with plasma samples collected from individuals vaccinated with doses of CoronaVac |
| Delta and Delta+ |
B.1.617.2 (Delta) |
India |
October 2020 |
L452R, T478K, P681R |
+97% |
Less sensitive to sera from naturally immunized individuals, whereas sera from vaccinated pre-infected individuals boosted the humoral immune response to well above the threshold of neutralization. Pfizer and AstraZeneca vaccines showed three- to five-fold lower potency compared to the alpha variant |
| B.1.617.2.1 or AY.1 (Delta+) |
K417N, V70F, L452R, T478K and W258L |
| Epsilon |
B.1.429 and B.1.427 |
California, USA |
July 2020 |
S13I, W152C, L452R |
+19–+24% |
Reduced neutralization by convalescent sera and BNT2b2, mRNA1273 vaccine-elicited sera |
| Zeta |
P.2 |
Rio de Janeiro, Brazil |
April and November 2020 |
E484K, but not the N501Y and K417T |
Not defined |
Decreased neutralisation of 5.8-fold for Pfizer–BioNTech COVID-19 vaccine (BNT162b2) and 2.9-fold for Moderna COVID-19 vaccine (mRNA-1273) |
| Eta |
B.1.525 |
UK |
December 2020 |
E484K and F888L |
+29% |
BNT162b2 vaccine-elicited antibodies showed a similar neutralization effect on B.1.1.7 |
| Iota |
B.1.526 |
New York, USA |
November 2020 |
E484K, S477N, N501Y |
+35% |
This variant is partially or completely resistant to two therapeutic monoclonal antibodies in clinical use and less susceptible to neutralization by convalescent plasma or vaccine sera |
| Kappa |
B.1.617.1 |
India |
October 2020 |
L452R, D614G, P681R, E484Q |
+48% |
Showed similar neutralization with the alpha variant against B.1.617.1 with sera of vaccinated individuals by Covaxin or Covid 19 recovered cases |
| Mu |
B.1.621 and B.1.621.1 |
Colombo, Sri Lanka |
January 2021 |
E484K, N501Y, P681H, K417, R346K and D950N |
Not defined |
Mu variant is highly resistant to sera from COVID-19 convalescents and BNT162b2-vaccinated individuals |
| Omicron |
B.1.1.529 |
South Africa |
November 2021 |
E484A, Q493R, T478k, N501Y, Q498R |
2–3 times more transmissible than other variants |
Recent studies on the ability of RBD neutralizing antibodies (NAbs) of 247 human anti-RBD NAbs have shown that 85% of the tested NAbs were escaped by Omicron |
