Synthetic vaccine and process for producing same

There is provided a synthetic vaccine against influenza virus infections consisting of a synthetic peptide corresponding to a relevant antigenic fragment of the virus, which fragment is attached to a suitable carrier, such as a macromolecule. Effective vaccinations against a plurality of strains can be obtained when the antigenic fragment is one common to such strains. Such synthetic vaccines are produced by synthesizing peptides corresponding to such relevant antigenic fragments and coupling same to a suitable carrier, such as a macromolecule. There is also provided a process for the vaccination of mammals against influenza which comprises applying to said mammals an effective quantity of a vaccine according to the invention.