Prevalence of notable mutations in receptor binding sites, antigenic sites (Sa, Sb, Ca1, Ca2 and Cb) and amino acids fixed in each cluster among patient categories.

aAmino acids numbering start after signal peptide DTLC.bP value>0.10 is considered not significant (ns); P value between 0.05 and 0.10 was considered a trend of significance; significant P value under 0.05 are in bold.cData not available for all sequences.