Statistical analyses
Statistical analyses were performed using GraphPad Prism software v9.1.2 (La Jolla, California, USA). Multiple group comparisons for serum neutralization titers against a set of samples and the two SARS-CoV-2 pseudotyped viruses were applied using Kruskal-Wallis test with false discovery rate (FDR) method, and multiple testing correction was performed for each comparison using Benjamini-Hochberg (BH) procedure at a 5% FDR threshold. When indicated, factor change was calculated as the difference of geometric mean titer in the pVNT