A recent review paper compiling various studies regarding norovirus susceptibility and genotypes (secretor status and ABO blood types). These studies are both voluntary infection studies, and cases of natural infections. FUT2, along with FUT1, is responsible for expression of the H antigens — these are what become modified to become A, B, and O types. FUT1 is responsible for expression in red blood cells, while FUT2 is responsible for secretion in mucosal tissues & saliva. This variant (FUT2-W154X) results in “non-secretor” status: individuals homozygous for this do not express the ABO antigens on their mucosal tissues / saliva (but still do on their red blood cells).
In general non-secretors are found to be almost completely resistant to norovirus. Notably, there are reports of some strains where non-secretors are susceptible. Consistent with this, binding studies using virus-like particles find a secretor-dependent binding pattern. These seem to be an exception among norovirus strains, however.
Groups have also reported variable binding to the different ABO in some strains (while other strains do not have such a bias) — for example, blood type B doesn’t seem to be bound by the GI.1 strain (while O, A, and AB are). This may explain why there are some reports of variability in norovirus susceptibility base on ABO type (with O generally more sensitive).