A potentially contaminated batch of a US-made vaccine for children has not caused any adverse effects in China, but public health officials will continue to monitor the situation, Yan Jiangying, spokeswoman of the State Food and Drug Administration, said.

She was responding to the worldwide recall of 1.2 million doses of the vaccine Hib produced by Merck & Co, a US-based pharmaceutical maker.

"No cases have been detected in which children in China have been affected by Hib," she said. "Medical institutions nationwide have stopped administering the vaccine, and the existing stock has been sealed."

The company announced on Wednesday that it had discovered a sterilization problem at a factory in Pennsylvania. The subsequent recall involved Hib, a vaccine that protects against meningitis, pneumonia and other dangerous infections, and a serum that combines Hib with a hepatitis B vaccine.

About 100,000 doses of Hib have been available in China since October, Yao Rui, who works at Merck's Beijing office, told the Legal Mirror on Friday.

The company said on its website the chances that any individual dose of vaccine is contaminated are low, and even in cases in which contamination has occurred, the amount is likely to be small.

Health officials said contaminated doses of the vaccine will cause skin irritation, swelling and redness around the spot where the shot was given.

The Associated Press reported that any negative effects would appear within a week of vaccination, and that there have been no reports of such side effects worldwide.

Yao said the company had already informed drug watchdogs, centers for disease control, Merck distributors and the general public about the recall.

"Merck is strictly abiding by China's Provisions on Drug Recall, officially released this week, and is willing to closely cooperate with the SFDA to pull back the vaccine with possible health risks," Yao said.

SFDA spokeswoman Yan confirmed on Friday the company had reported the recall.

"The SFDA received the recall report from Merck, and immediate action was taken to track down and help recall the products in China," she said.

The Provision on Drug Recall obliges manufacturers of imported drugs to provide Chinese authorities with full details of product recalls to avoid potential health hazards. It also provides for the easing or waiver of administrative punishments for firms that conduct drug recalls voluntarily.

"However, due responsibilities such as legal liability and compensation claims from people who have been harmed by such products cannot be waived," Yan said.

(China Daily December 15, 2007)