Wang et al. found that this variant is refractory to neutralization by convalescent plasma and vaccine sera . McCarthy et al. found that 90% of deletion mutations occupied four discrete sites within the NTD . What is worth mentioning is that SARS-CoV-2 Lambda (B.1.621) variant , a new variant of interest with higher infectivity and immune resistance, has T76I, L452Q, F490S and a unique 7-amino-acid insertion mutation (RSYLTPGD246-253N) in the N-terminal domain . All of above have made the current drug development situation even grimmer. Hence, it matters laying emphasis on immunogenicity of different S protein domains and the specific mechanism of mAbs targeting them, including NTD.