H3 influenza a virus

A method of preparing a vaccine, comprising

• combining an isolated live H3 influenza virus comprising a gene segment with sequences for a HA or a HA-1 having at least 95% amino acid sequence identity to SEQ ID NO:
• 1, where the HA or the HA-1 has an alanine at position 78 and a serine at position 159, and has a residue other than methionine at position 29, a residue other than lysine at position 54, a residue other than serine at position 83, a residue other than asparagine at position 92, a residue other than leucine at position 222, a residue other than alanine at position 272, or a residue other than threonine at position 328, with an adjuvant or a pharmaceutically acceptable carrier, or treating the isolated H3 influenza virus with an agent that inactivates the isolated H3 virus or under conditions that freeze-dry the isolated H3 virus, thereby providing a composition;
• and
• providing an individual dose of the composition comprising an amount of the H3 influenza virus effective to immunize a mammal.