Vaccines and antibody therapeutic are needed to fight the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that has spread since 2020. Experimental studies have shown that the E484K variant may escape the neutralization of antibodies. To explore the potential impact of E484K mutation on the antibody binding affinity, we calculated the binding free energy of 28 antibodies to the wild type and K484 mutant of the spike protein of SARS-CoV-2. We found that 71% of the antibodies show lower binding affinity to the E484K mutant, indicating the highly possible immune escape risk of the mutated virus. Further analysis revealed that the other mutations, e.g. F490 and V483, are also likely to cause immune escape.