No. of tetramer+ samples/total no. of blood samples2
1 No. of samples with detectable Tax-specific CD8+ T-cells/total no. of samples carrying each HLA allele. When the frequency of tetramer+ cells was more than 0.04% of CD8+ T-cells, the sample was regarded as detectable.
2 In case Tax-specific CD8+ T-cells was detectable by either tetramer in a sample carrying two of three HLA-A alleles above, the sample was regarded as positive.