Sinovac Biotech has got approval from health authorities to mass produce a vaccine for the H1N1 strain of flu, prompting the company to raise its annual sales forecast.

China's State Food and Drug Administration (SFDA) gave the green light yesterday for the Panflu vaccine, which Sinovac says needs only one 15 microgram dose to be effective.

Worldwide, pharmaceutical firms are in a race to produce vaccines against H1N1 before the northern hemisphere winter, when experts warn the flu could spread wider.