FIG 1 .

Long-term in vivo evolution results in loss of GII.4 epitope F, a conserved GII.4 blockade antibody epitope. (A) Virus-like particles representing norovirus sequences isolated from an immunocompromised transplant patient over a 683-day period were evaluated for binding to MAbs GII.4F and GII.4G by enzyme immunoassay. Both MAbs recognize conserved GII.4 blockade epitopes that overlap each other and are occluded by structural conformation. Error bars represent 95% confidence intervals. Values that are significantly different (P < 0.05) from the day 1 value are indicated by an asterisk. (B) After a minimum of 581 days of in vivo evolution, capsid sequence changes, indicated by color changes, resulted in loss of binding of human MAb GII.4F but not mouse MAb GII.4G.