Comparison of variant frequencies associated with cell culture passage, passage under antiserum selection, and mAb selection.

Mutations that are present in at least 1 sample at > 5% are shown and that are present in antiserum passaged samples and/or neutralization data are shown (see S1 Table for mutations present at 1% or greater). Note cell passaged samples from Vero and Caco-2 cells did not have mutations that persisted and are not shown. Antiserum passaged samples (VA-P6) have serum dilution (1:5 or 1:10) shown in parentheses. Samples that were tested with the neutralization assay are denoted by the mAb name, the viral inoculum (UP, VO-P6, or VA-P6), and the mAb concentration (5 μg/ml, 10 μg/ml). Data from virus only passaged samples (no antibody selection) are shown in blue cells and data from virus passaged under antiserum or mAb selection are in yellow shaded cells. Top row cells shaded grey signify columns with data from both virus only and antibody selection. With the exception of Vero P4, Vero-T P4 and Caco P4, all samples were processed (PCR and sequencing) in duplicate; the percent frequency is an average of the two values.