The Chinese government has mounted "a very robust response" to the threat of A/H1N1 influenza and the efforts are paying off, the head of World Health Organization (WHO) said on Thursday.

"The ministry of health under the coordination of government leaders mounted a very robust response so that they are able to track down all the cases," Dr Margaret Chan told Xinhua in an interview.

"So far the efforts are paying off," she added.

The WHO director-general reiterated the unpredicability of the H1N1 virus and stressed the importance of continued surveillance as well as response adjustments.

"And of course my advice to them is that they need to adjust their public health response in line with the changing pattern of this virus," she said.

"It's important that they do not let their guard down," she added.

(Xinhua News Agency May 29, 2009)