https://phys.org/news/2018-07-molecules-breast-seaweed-strategies-norovirus.html

To develop this strategy, however, researchers needed to understand which features of fucose and virus molecules affected how well they attached to each other. In cells, foods, and milk, fucose is rarely found as a single molecule; rather, it's part of chains or networks of sugars and proteins. Franz-Georg Hanisch, a researcher at the University of Cologne, led a project to disentangle these molecular elements and understand what kind of fucose-based product would best distract noroviruses. He started by screening the many types of fucose-containing human milk oligosaccharides (HMOs).

To Hanisch's surprise, the strength of the binding between the norovirus protein and HMOs did not depend much on the specific structure of the HMO, or the types of fucose molecules it contained. Rather, what mattered was only how many fucoses it contained. Each individual fucose stuck weakly to the virus protein, but the more fucoses there were in the compound, the better the compound and the viral protein stuck together.