BEIJING, Dec. 25 (UPI) -- Chinese health officials said they are investigating a vaccine producer because several infants have died after being injected with a hepatitis B vaccine.
Six babies in total have died, four after receiving a vaccine produced by Shenzen Kangtai Biological, a privately run drug company with a 60 percent market share for hepatitis B vaccines in the country.
Health officials have banned the use of the Shenzen's vaccines while the investigation takes place. The New York Times said Wednesday doctors have yet to positively link the infant deaths to the vaccine but said it is the most likely cause.
Shenzen was founded in 1992 under a rare partnership with the U.S. drug company Merck, which gave Shenzen the technology necessary to produce common vaccines in a bid to improve public health. At the time, the hepatitis B vaccine was not widely given to newborns, leading to millions of children suffering from the chronic liver disease, which in some cases can be fatal.