HONG KONG – Authorities in China have now banned all hepatitis B vaccines (HBV) produced by Shenzhen Kangtai Biological Products Co. after the deaths of five more children.

The China Food and Drug Administration (CFDA), together with National Health and Family Planning Commission (NHFPC), took the vaccines produced by Shenzhen Kangtai (also known as Biokangtai) and continue to investigate. Authorities had, at first, pulled two batches of the product.

The CFDA said on Dec. 20 that distribution of all batches of Biokangtai’s hepatitis B vaccines would be suspended. Two batches of the vaccine – C20120708 and C201207090 – were suspended on Dec. 13 due to a suspected link with the deaths of two infants in Hunan Province in early December. Regulators stepped up the ban after five more deaths were reported in Guangdong and Sichuan provinces a few days later. According to the Center for Disease Control and Prevention of Guangdong Province, this southern province had dispensed 113,964 doses of a different batch of Biokangtai’s vaccine – C201207086 – as of Dec. 23.

To date, there are two deaths in Hunan, two in Sichuan and three in Guangdong Province.

Another infant was reported to have suffered a severe adverse reaction after being vaccinated with Biokangtai’s product in Hunan Province. The infant is a one-month-old boy who was vaccinated on Nov. 25. He spent two weeks in intensive care at a local hospital and is no longer in critical condition.

“Through inspection and tests, we will give accurate and scientific judgments on the quality of the vaccines and the production process of the company,” said Wang Huaqing, head of drug and chemicals inspection department of CFDA, during a recent press conference held by the CFDA. “According to the inspection [process], it will take about 20 days before the results come in. We will keep the public informed.”

China has included hepatitis B vaccination for newborns in the national immunization programs since 1992. In 2005, with the help of the World Health Organization (WHO), China set up an adverse reaction monitoring system. The system continues to evolve. In 2012 it collected data from more than 100,000 vaccinations. As the amount of data grew, more suspected cases of adverse reactions were reported.

“But the number of the cases didn’t exceed the WHO suggested range,” said Wang.

Biokangtai is the biggest hepatitis B vaccine maker in China with coverage across 31 provinces. There are several other manufacturers including Beijing Tiantan Biological Products Co., Hualan Biological Vaccine Co. and Dalian Hissen BioPharm Co.

“These five companies, other than Biokangtai, have 25 million doses of qualified hepatitis B vaccine and obtained the lot release certificate,” said Wang. “They are ready for vaccination, if there was a temporary shortage, we will ask the companies to maximize their production if necessary.”

The WHO has shown its concerns and support for the investigation.

“These deaths are very unfortunate, but the rapid reporting and investigation of the government speaks to the strength of the health and drug regulatory system to identify adverse events quickly and take action to prevent additional problems,” said the WHO’s China Representative Bernhard Schwartlander in a note the CFDA posted on Dec. 27. “The health gains of the vaccination program are enormous and all the efforts should be directed towards the continuation of the vaccination program while ensuring the safety of the vaccines.”

In China, there are currently three kinds of hepatitis B vaccines in use. One is a recombinant HBV (Saccharomyces Cerevisiae) manufactured by Biokangtai and Beijing Tiantan. A second is a recombinant HBV (Hansenula Polymorpha ) manufactured by Hissen. The third is a CHO cell expression vaccine.

“(The) recombinant HBV (Saccharomyces Cerevisiae) has been on the market since 1996,” said Zhao Kai, researcher at Beijing Biological Preparations Institute during a press conference. “It has been 17 years now.”

Newborns are vaccinated three times at birth, one month and six months old. Infants are required to receive the first vaccination within 24 hours after birth.

Recombinant HBV (Saccharomyces Cerevisiae) is Biokangtai’s major product. The company said that the two deaths in Hunan Province were “suspected coincidental death cases” that are most common after vaccinations and can lead to misunderstandings.

The company has rejected all requests for interviews, but said updates will be issued when relevant.