Table 1.

List of RBD mutants and escape variants along with their effects on ACE2 binding and antibody recognition.

RBD mutants	Effect on ACE2 binding with respect to wild-type	Effect on neutralizing antibody and immunity
E340K	Decrease [19]	Resistance to a broadly reactive NAb, S309 [19]
N343A	Loss of ACE2 binding [19]	Impaired neutralizing antibody generation [20]
T345I	Limited effect [17]	Efficient binding of all NAbs [17]
R346S	Limited effect [19]	Resistant to C135, but retained full sensitivity to both C121 and C144 [21]
V367F	Increase [22]	Low binding affinity in HLA-A01:01, HLA-B07:02, and HLA-B35:01 compared to the wild type [23]
R408I	Limited effect [24]	decrease the binding affinity of S protein to the CR3022 antibody [24]
K417N	Moderately decrease [25]	Resistance to plasma samples, as the NAb titers were approximately 2–4 times lower than those for the wildtype [19]
K417T	Moderately decrease [25]	Capable of antibody escape [17]
N439K	Increase [13]	Confers resistance against several neutralizing monoclonal antibodies, escapes some polyclonal responses [13]
N440Y	Limited effect [17]	Disrupted fewer NAb interactions [17]
G446V	Decrease [17]	Demonstrated escape to COVA2-15 and C135 mAbs [26]
N450K	Limited effect [19]	Immune escape the neutralization by monoclonal antibodies and human convalescent sera [27]
L452R	Increase [28]	confer escape from HLA-A24-restricted cellular immunity [28]
Y453F	Increase [15]	Confer escape from HLA-A24-restricted cellular immunity [28]
A475V	Decrease [17]	Less binding to multiple class I antibodies [17]
G476S	Decrease [29]	Shortened a linear B cell epitope length and even abolished the discontinuous B cell epitope [23]
S477N	Increase [25]	resistant to neutralization by multiple monoclonal antibodies [27]
S477G	Moderate increase [30]	Conferred resistance to sera [27]
T478I	Unaltered [31]	Reduced neutralization by monoclonal antibodies and human convalescent sera [27]
E484K	Increase [25]	Less sensitive to neutralization by convalescent human sera, evades antibody neutralization elicited by infection or vaccination [32]
E484Q	Limited effect [33]	Limited effect on immune invasion [14]
F486L	Decrease [34]	Resistance to plasma samples, as the NAb titers were approximately 2–4 times lower [19]
F490S	Limited effect [19]	Predicted to be markedly resistant to neutralization by LY-CoV555 [35]
Q493L	Beneficial [36]	Possible vaccine escape [11]
S494P	Increase [9]	Reduces antibody neutralization of convalescent and post-immunization sera [37]
N501Y	Increase [25]	272 convalescent sera showed reduced binding of anti-RBD IgG to N501Y [38]
Y505W	Increase [17]	Efficiently binds to different Nabs [17]