a, Neutralization of B.1.1.7, B.1.351 and wild-type viruses by additional RBD-directed monoclonal antibodies. Data are mean ± s.e.m. of technical triplicates. b, Fold increase or decrease in IC50 of neutralizing monoclonal antibodies against B.1.1.7 and B.1.351, as well as mutant pseudoviruses, relative to the wild type. Red, resistance >3-fold; green, sensitization >3-fold.