Methods for producing virus particles and viral antigens with simplified glycosylation profiles, such as mono-glycosylated forms of HIV, HCV, Dengue virus, West Nile virus and influenza virus. When used as targets for vaccine production, the conserved nature of such sites generate vaccines that are less sensitive to viral mutations. Such methods may include the use of glycosylation inhibitors for production of viruses or viral antigens with simplified glycosylation profiles.