This is NEWS Plus Special English. I'm Mark Griffiths in Beijing.
China reports more human cases of H7N9 bird flu after researchers in Shanghai announced preliminary success in developing a vaccine.
China has so far reported more than 120 human H7N9 cases this year, including over 25 deaths, with Zhejiang and Guangdong being most affected.
Shanghai Public Health Control Center says its genetically engineered vaccine had passed preliminary animal tests in laboratory mice.
The center says the vaccine would have to go through a clinical test to prove its effectiveness in protecting humans before being put into use.
China's National Health and Family Planning Commission has reaffirmed that no proof has been found that the H7N9 virus is spreading from human to human, adding that all H7N9 patients have been isolated.
In a related development, Vietnam has issued an emergency circular urging its provinces and big cities to beef up the prevention and fight against H7N9 bird flu.
The circular says although Vietnam has not reported any H7N9 infection so far, but it has witnessed two deaths caused by H5N1 virus since the beginning of this year.
Vietnam's health ministry says the risks of H5N1 bird flu have loomed large to be able to spread in Vietnam together with the threat of H7N9 bird flu from neighboring countries.
It urges related departments to strengthen supervision over possible bird flu infections at border check points, in communities and hospitals. It also calls for more education of its citizens to fight against the disease.
