Sanofi Pasteur has released the final data from trials of the US-licensed influenza A H1N1 vaccine that confirm its immunogenicity and safety profile.

The trial confirmed that one dose of the influenza A H1N1 monovalent vaccine induces a robust antibody response in adults but two doses of the vaccine are needed to ensure the same in children aged nine years and younger.

The trial found there were no serious vaccine-related adverse events during the 42 days of follow-up of the adult and paediatric trials, the company said.

By the end of this week, Sanofi will have shipped 20 million doses of H1N1 vaccine, according to CNN.