This article, published by the WHO, answers frequently asked questions about the A(H1N1) influenza virus, or 'swine flu'. It provides information on the availability, production and effectiveness of A(H1N1) vaccines.

The WHO says that no effective A(H1N1) vaccines are currently available (May 2009) but adds that work is underway to develop one. The Centers for Disease Control and Prevention in the United States, for example, has identified and prepared candidate vaccine strains and is distributing them to all interested parties on request.

A vaccine could be available in five to six months after a pandemic strain has been identified but the WHO notes that more than 90 per cent of the global capacity for vaccine production lies in Europe or the United States — which may have implications for vaccinating people in developing countries. While these countries are well-versed in distributing vaccines through mass campaigns, they may face difficulties in ensuring timely access to enough supplies of vaccine.