China has stepped up public health warnings as children return to school
Chinese health authorities have approved a vaccine that they say prevents swine flu with a single dose.
Chinese vaccine maker Sinovac has been given the green light to mass produce the vaccine for the H1N1 flu strain.
The government has said it plans to have enough vaccine to cover 5% of the population by the end of the year.
More than 5,000 cases of swine flu have been confirmed in China. The World Health Organization says the situation in the country is "quite stable".
The vaccine by Sinovac is one of several being developed in China. Experts say more results are needed from other makers to determine whether one dose would be potent enough.
Public health warnings to prevent the spread of swine flu have increased in the last week, as children return to school after the summer break.
A high school in Xin'an county, near Luoyang in Henan province, was closed over the weekend after 80 students were diagnosed with the flu.