Infant deaths after inoculation using the recombinant hepatitis B vaccine produced by the Shenzhen-based Biokangtai company have now risen to at least seven nationwide, Beijing Times reported.

The China Food and Drug Administration (CFDA) and the National Health and Family Planning Commission (NHFPC) on Friday jointly issued a circular to ban the use of the vaccine.

An official investigation is underway. An infant in Shenzhen who became sick just minutes after a hepatitis B vaccination and died an hour later was reported yesterday to possibly have been the fourth victim of vaccines produced by Biokangtai. The company has not said where vaccines may have been sold that came from the same batch as the Shenzhen baby received.

An average of around 50,000 Chinese are born every day, according to official estimates, and most get the hepatitis B injection shortly after birth.

Biokangtai, established in August 1988, has a 60 percent share of the market and sales of 10 million vaccines a year in China, according to The Time Weekly.