Antisera to QW101-like (QW126) porcine NoVs crossreacted with VLPs of human GII NoVs in ELISA and Western blot. In ELISA (Table 4) , the pig convalescentphase antiserum (LL616) to QW101-like porcine NoV QW126 strain showed higher titers (1:400-1:800) to GII-3/Toronto, GII-4/MD145, GII-4/HS66, and GII-6/Florida strains; a lower titer (1:100) to GII-1/Hawaii strain; and lowest titer (1:10) to GI-3/Desert Shield strain. In Western blot ( Figure 5 ), the capsid proteins (59-60 kDa) of Toronto, MD145, HS66, and Florida strains, but not the Hawaii and Desert Shield strains, were detected by pig antiserum LL616 but not the negative control serum (data not shown). Thus, 1-way antigenic cross-reactivity exists between human NoV antigens and porcine NoV (GII-18) antiserum, with moderate cross-reactivity to human NoVs GII-3, 4, and 6; low cross-reactivity to GII-1; and very low cross-reactivity to GI-3.