The invention provides methods for vaccinating against influenza, comprising administering multiple times to a subject a vaccine that comprises influenza hemagglutinin (HA) and neuraminidase (NA) proteins from at least a first influenza strain, wherein the HA and NA proteins of the first influenza strain are administered to the subject at least three times within a period of less than one year. Such immunization schemes induce cross-protection against heterologous and heterosubtypic influenza strains.
