American pharmaceutical giant Pfizer has stopped selling one of its lucrative vaccines for children in China, the company said.
Pfizer gave no explanation for stopping its sales of the Prevnar vaccine, which helps prevent infections such as pneumonia, which killed an estimated 935,000 children under the age of five globally in 2013, according to the World Health Organization.
"Based on a careful assessment of this situation, we have decided to cease our vaccines commercial operations in China at this time, effective immediately," a spokeswoman said in an email Thursday, adding that the drug's import license had expired.
Pfizer anticipates a shortage of Prevnar in China before the sale of a new vaccine can begin.
Prevnar vaccines generated $4.5 billion in revenue last year for Pfizer. They are the second largest contributor to the company's revenues, according to Pfizer's annual report.
The spokeswoman said that the other activities of the company, which employs about 9,000 people in China, were not affected. China is one of Pfizer's largest markets after the US and Canada.
About 200 positions at the company will be affected by the end of the vaccine sale.
The setback comes as pharmaceutical companies have struggled to gain Chinese authorities' approval for many of their drugs.
Pfizer said it is in talks with Chinese regulators to register and provide an improved vaccine "as soon as possible."