a, Neutralization profiles for 22 serum samples obtained from individuals who received the SARS-CoV-2 vaccine made by Moderna (V1–V12) or Pfizer (V13–V22) against B.1.1.7, B.1.351 and wild-type viruses. The horizontal dotted lines on each graph indicate 50% and 0% neutralization. Reciprocal serum dilutions are given as 1:X, in which X is the value on the x axis. Data are mean ± s.e.m. of technical triplicates and represent one of two independent experiments. b, Fold change in serum neutralization ID50 of B.1.1.7 and B.1.351 viruses, B.1.1.7Δ8, B.1.351Δ9 and single-mutation pseudoviruses relative to the wild-type virus, presented as a heat map in which darker colours indicate greater change. Red, resistance >2.5-fold; green, sensitization >2.5-fold. c, Change in reciprocal serum ID50 values for individuals who received the Moderna and Pfizer vaccines against B.1.1.7, B.1.351, B.1.1.7Δ8 and B.1.351Δ9 relative to the wild-type virus. Mean fold change in ID50 relative to the wild-type virus is written above the P values. Statistical analysis was performed using a Wilcoxon matched-pairs signed-rank test. Two-tailed P values are reported.