The total number of epitope variants, and the total number of sequences available.

This summary includes all sequences from samples spanning the period of study used for 454-pyrosequencing, comparing conventional (SGA) sequencing and 454 pyrosequencing. “SGA sequence Count” refers to the number of individual sequence isolates determined by SGA sequencing in previous studies; “SGA Epitope Count” gives the number of unique amino-acid sequences at the epitope site as determined by SGA sequencing; “454 sequence count” and “454 Epitope Count” give the corresponding (and much larger) numbers determined in this study; “Repeated Variant Count” refers to the number of epitope-site peptide sequences that were found more than once among the 454 sequences.