The invention relates to an active ingredient which is a live attenuated recombinant measles virus expressing influenza A virus antigen(s) and to its use in the elicitation of immunity, in particular protective immunity and advantageously broad-spectrum protective immunity against influenza A virus. In particular, the influenza A virus is selected among epidemic seasonal viruses and/or endemic viruses circulating in the human population and advantageously encompasses a pandemic virus such as H1N1v.
