Fucoidan but not 2'-Fucosyllactose could inhibit human norovirus replication in zebrafish larvae

Human noroviruses (hNoVs) cause heavy disease burden worldwide and there is no clinically approved vaccination or antivirals hitherto. In this study, with the use of a zebrafish larvae in vivo platform, we investigated the anti-hNoV potentials of fucoidan and 2-Fucosyllactose (2-FL). As a result, although both fucoidan and 2-FL were able to block hNoV GII.4 virus-like particle (VLPs) from binding to type A saliva as expected, only fucoidan but not 2-FL was able to inhibit the replication of hNoV GII.P16-GII.4 in zebrafish larvae, indicating the possible needs of higher molecular weights for fucosylated carbohydrates to exert anti-hNoV effect.