Malfunction led to problem vaccines

Top drug authority points to uneven ratio of liquid in doses to be packaged

China's top drug regulator said on Tuesday that a temporary equipment malfunction led to more than 400,000 ineffective vaccines, often used for infants and children, being sold in two provincial regions.

A total of 400,520 doses of DTaP vaccine made in 2016 by Wuhan Institute of Biological Products Co, in Wuhan, Hubei province, were sold in Chongqing municipality and Hebei province.