As governments and scientists rush to analyse the threat of the new influenza strain, investors are hurrying to spot which companies might stand to benefit. EP Vantage has identified 23 companies which have registered significant share price gains that can be attributed to the health scare, since news of the situation in Mexico began to make headlines last Friday (see table below).

Overall, $23.2bn has been added to the combined market cap of this group, a figure that is unlikely to be translated into real value in the long term. Of the group only nine could be in line for tangible benefits, most notably GlaxoSmithKline and Roche, in the shape of a surge in demand for antiviral drugs Relenza and Tamiflu. Realistically, very few of the smaller drug developers working on early stage, experimental vaccines with limited proof of efficacy are likely to end up winners in the short-term.