China is gearing up for an upward battle against an H1N1 flu pandemic, expected to peak in the autumn-winter season and infect tens of millions of people across the country, a health ministry official said yesterday.

Severe cases or even fatalities will be unavoidable, warned Liang Wannian, deputy director of the ministry's emergency office, on Friday

"Half of the patients could develop clinical symptoms and several million will seek medical help," he said at a regular press conference.