The nation is confronted with a new front in the battle to contain the A/H1N1 flu outbreak as the virus spreads into the vast countryside where medical facilities lag far behind cities, health officials and experts warned yesterday.

As the pandemic appears to be declining in cities where a nationwide A/H1N1 vaccination program has started, the Ministry of Health pledged to concentrate more on rural areas, particularly schools, for prevention and control.

Students, pregnant women and the chronically ill are at particularly high risk, and so special attention will be paid to them, said an online statement issued by the ministry over the weekend.

The risk of outbreaks in the countryside will increase as hundreds of millions of migrant workers in cities go back to their rural homes for the Spring Festival, which falls on Feb 14.

"They might take the virus back to their hometowns," Feng Zijian, who heads the emergency response department of the Chinese Center for Disease Control and Prevention (CDC), said yesterday.

In response, the government is rushing medical equipment such as respirators to 17 central and western provinces, particularly rural areas, to "increase the overall ability to deal with severe cases", the statement said.

By the end of last year, the nation had reported 120,000 lab-confirmed A/H1N1 cases, including 648 deaths, official figures showed.

Nearly 50 million had been vaccinated against the flu by December 31, falling short of the 65 million target announced by Health Minister Chen Zhu.

In many parts of the country, vaccinations are first given to the high-risk population with local permanent residency permits, or hukou, largely due to limited vaccine supplies, according to previous reports.

Health experts estimate that 15 percent of the population have thus far developed immunity to the virus, the statement said.

In other words, A/H1N1 vaccine recipients and those who have contracted the virus - without their cases being officially reported - could amount to about 195 million, Zeng Guang, CDC's chief epidemiologist, explained yesterday.

"The immunity level will increase as the virus keeps spreading," he added.

The higher the proportion of individuals who are immune, the more unlikely the virus would spread, health studies show.

However, "as long as susceptible individuals and the virus exist, the battle against A/H1N1 cannot stop, especially in rural areas", he said.

Meanwhile, the ministry called for a rational attitude toward the disease among the public.

"There is no need to panic. Passengers who display flu-like symptoms should not be driven out of the public transport. A facial mask would work well to prevent infection," it said.

Media reports said some migrant workers traveling by public transport during the New Year holiday were thrown out by other passengers for showing flu-like symptoms.