China has entered the peak flu season, but the prevalence of the disease will be lower than last year, China's top health authority said on Friday.

Flu outbreaks will gradually decrease due to reduced chances of infection with schools and infant nurseries closing for the winter vacation, the National Health Commission said.

Prevalence of the flu is still rising in southern regions, but at a slower rate, while prevalence remains stable in the north, Lei Zhenglong, deputy chief for disease control and prevention at the commission, said at a news conference.

Following last winter's serious flu outbreaks, the worst in recent years, health authorities intensified monitoring outbreaks and efforts for disease prevention and control this year.

The National Health Commission has worked with several other departments to carry out measures such as improving sterilization and ventilation at key spots such as schools, railway stations and airports to minimize risks of flu outbreaks, Lei said.

Following a shortage in the supply of flu vaccines in some parts of China last fall, health authorities increased purchasing and now can meet demand, he said.

Health authorities across China have bought more than 14 million doses of flu vaccines, and nearly 11 million of them have been used, he said.

Li Zhongjie, a researcher at the Chinese Center for Disease Control and Prevention, said nationwide monitoring shows H1N1 is the major virus in circulation this winter, and the flu vaccines available are effective in preventing the virus.

"Seasonal flu usually peaks in winter and spring in most parts of China, and it is a common disease," he said. "But certain groups who have higher risks of complications should pay particular attention to prevent flu, including children under 5 years old, elderly above 65 years old, the pregnant, and people with chronic diseases including respiratory diseases, diabetes and cardiovascular diseases."

Catching the flu is more likely in enclosed places, including office buildings, and good hygiene practices such as hand washing can help prevent infection, he said.

Guo Yanhong, deputy chief for medical administration and supervision at the National Health Commission, said with the arrival of the traditional Chinese New Year, a most important festival for family reunion and gatherings, medical institutions will also remain on duty.

"We have ordered local health authorities and medical institutions to assign staff to be on 24-hour duty every day during the holiday, to ensure people have a happy and healthy Spring Festival," she said.