Table 3.

Variants of Concern: Mutations and their key features.

Pango Lineage/First Detected/ WHO Classification	Spike Protein Substitution	Other Mutations	Key Features
B.1.1.7 United Kingdom ALPHA (WHO)	Receptor-binding domain: N501Y Furin cleavage site: H69del, V70del, P681H Other mutations including N-terminal: A570D, T716I, S982A, D1118H Antibody supersite epitope: _Y144del, +/−E484K	NON- SYNONYMOUS Open reading frame (ORF)1ab: T1001I, A1708D, and I2230T. ORF8: Q27stop, R52I, and Y73C Nucleocapsid (N) protein: D3L and S235F SYNONYMOUS ORF1ab: C913T, C5986T, C14676T, C15279T, and T16176C Membrane (M) gene: T26801C DELETIONS ORF1ab: SGF 3675–3677del	✓ Increased transmission rates by ~50% [64] ✓ Potential increased severity (hospitalization and mortality rates) [81,82], but controlled studies indicate no increased severity [76,102] ✓ Negligible risk of reinfection [103] ✓ No effect on susceptibility to monoclonal antibody therapies ✓ Minimal impact on neutralization by convalescent and vaccine sera [62,83,104,105,106,107] ✓ No evidence of elevated reinfection rates [76] ✓ The presence of E484K led to a six-fold decrease in sensitivity of this E484K mutant virus to immune sera from individuals vaccinated with vaccine and an 11- fold decrease in sensitivity to convalescent sera [106]
B.1.351 South Africa BETA (WHO)	Receptor-binding domain: K417N, E484K, N501Y. N-terminal domain: L18F, D80A, D215G, R246I, D614G deletion at 242–244. S2 subunit: A701V.	NON- SYNONYMOUS ORF1ab: _T265I, _K1655N, H2799Y, S2900L, K3353R, D4527Y, T5912I ORF3a: Q57H, S71L Envelope (E): _P71L N viral protein: _T205I	✓ Increased transmission rates by ~50% [82] ✓ Possible increased risk of in-hospital mortality [108,109] ✓ Reduced efficacy of some monoclonal antibodies [81] ✓ Reduced neutralization by convalescent and vaccine sera [86]
P.1 Brazil GAMMA (WHO)	Receptor-binding domain: K417N, E484K, N501Y N-terminal domain: L18F, T20N, P26S, D138Y, R190S, Carboxy(C)-terminal region of the S1 domain: D614G S1 and S2 site: _H655Y, T1027I, and V1176F	NON- SYNONYMOUS Open reading frame (ORF)1ab: S1188L, K1795Q, and E5665D ORF8: E92K Nucleocapsid (N) protein: P80K SYNONYMOUS ORF1ab: C913T, C5986T, C14676T, C15279T, and T16176C Membrane (M) gene: T26801C DELETIONS ORF1ab: _SGF 3675–3677del	✓ 2.6 times more transmissible [110] ✓ Possible increased risk of hospitalization [111] ✓ Reduced efficacy of some monoclonal antibodies [112] ✓ Reduced neutralization by convalescent and vaccine sera [86,113]
B.1.617.2 DELTA (WHO)	Receptor-binding domain: L452R, T478K Carboxy(C)-terminal region of the S1 domain: D614G Furin cleavage site: P681R	Spike protein: D950N, G142D, T19R, 156del, 157del, R185G	✓ Increased transmissibility [113] ✓ Secondary household attack rate elevated [96] ✓ Possible increased risk of hospitalization [114] ✓ Potentially reduced neutralization by monoclonal antibody treatments [115] ✓ Potentially reduced neutralization by vaccine sera [116]