Immunogenic compositions comprising partially glycosylated viral glycoproteins for use as vaccines against viruses are provided. Vaccines formulated using mono-, di-, or tri-glycosylated viral surface glycoproteins and polypeptides provide potent and broad protection against viruses, even across strains. Pharmaceutical compositions comprising monoglycosylated hemagglutinin polypeptides and vaccines generated therefrom and methods of their use for prophylaxis or treatment of viral infections are disclosed. Methods and compositions are disclosed for influenza virus HA, NA and M2, RSV proteins F, G and SH, Dengue virus glycoproteins M or E, hepatitis C virus glycoprotein E1 or E2 and HIV glycoproteins gp120 and gp41.