China on Friday pledged to step up a swine flu vaccination programme that has seen more than 32 million people jabbed, warning the upcoming holiday season could see a further spike in cases.

Officials told reporters prevention efforts faced a new challenge especially during the Lunar New Year, or Spring Festival, holidays in February when hundreds of millions of people travel.

"We are coming up on the New Year and Spring Festival holidays when much of the population is on the move, which could spread A(H1N1) to areas where it currently does not exist," said Liang Wannian, vice director of the ministry's medical emergencies office.

A total of 32,380,000 people had received jabs, the ministry said, under a massive nationwide programme launched nearly three months ago amid government fears of a winter surge in A(H1N1) influenza cases.

Those fears appear to have been borne out amid cold weather in recent weeks, with the number of deaths jumping to 325 as of Wednesday, according to the ministry. More than a third of those fatalities were reported in the first week of December.

The total number of A(H1N1) influenza cases surpassed 100,000 on Sunday, it said.

A statement issued by the ministry Friday said: "In the next phase, relevant departments involved in prevention and control work must step up coordination and accelerate the promotion of flu vaccination efforts."

The ministry also sought to address widespread concerns over the safety of the vaccinations, saying only one out of a million people inoculated had reported adverse reactions.

"One thing is certain, the most effective way to control the flu is through vaccinations," Liang said.

The ministry statement also said that A(H1N1) accounted for 91 percent of all flu cases in China.

Public concern over the safety of Chinese A(H1N1) vaccines emerged after some recipients reportedly experienced adverse reactions. The health ministry also has reported two people died after being inoculated.

Beijing had said it planned to vaccinate up to 65 million people by the end of the year.