Wednesday, 8 January 2014

Hepatitis B vaccine in China: the unanswered questions

Commentary by Michael Woodhead

The deaths of 17 Chinese infants reported as having have followed hepatitis B vaccination are a tragedy that needs to be be fully investigated. When the first deaths occurred, the suspicion lay with a vaccine made by Shenzhen BioKangtai, with reports that certain batches of the vaccine were linked to the deaths of newborns in several provinces who had received vaccines with the specific batch number. Matters then became confused when reports were made of deaths of infants who had received other vaccines, including one made by a company called Beijing Tiantan. In all, 17 deaths have been officially reported in relation to hepatitis B vaccine.
When the first deaths were reported, the China Food and Drug Administration (SFDA) and the National Health and Family Planning Commission (NHFPC) ordered a halt to the use of the Biokangtai vaccine in China's newborn vaccination program and an investigation into the vaccine used.

After a rapid investigation of less than two weeks it has been announced that no problems have been found with the batches of Biokangtai's vaccine reportedly involved in the deaths and adverse reactions. The SFDA has also found no problems in the manufacturing, storage, transport or injection of the vaccine. Nevertheless, manufacturing permissions have been suspended for the three major manufacturers of hepatitis B vaccine, on the grounds that their facilities had not met the new GMP criteria for vaccine prodiction that came into effect on 1 January.
Post-mortem investigations into the infant deaths have also excluded the vaccine in nine cases, so far, and the other eight cases are waiting for autopsy results. Thus the hepatitis B infant vaccination campaign has quickly been given the all clear by the various authorities, and this verdict has been endorsed by the local branch of the WHO. The WHO representative rightly pointed out that the hepatitis B program was based on a good vaccine and prevented many cases of diseases and death every year. However, the announcement about the vaccine being safe was met with anger from some of the families of the children who died, and there has been disbelief on online forums about the "all clear" verdict from netizens who have little faith in monitoring of safety and quality of foods and medicines in China.

Despite the endorsement of WHO, there are still areas of doubt and unanswered questions in relation to the safety of China's hepatitis B vaccine and other child vaccine programs. First of all, if a vaccine was not responsible for the infant deaths, what was or were the real causes? With millions of newborns being vaccinated it is statistically probable that some natural infant deaths will co-incide with the time of vaccination. But the reports of 17 deaths in association with hepatitis B vaccination require in-depth investigation. Another question is whether it is possible to confidently rule out the vaccine as a possible factor in the cause of death. The investigations into the child deaths and into the vaccine quality and usage were done very quickly, raising questions about how thorough and comprehensive they were. There was also little transparancy about the process.
By comparison, when a similar series of vaccine-linked adverse events was seen in Australian infants given flu vaccine in 2010, authorities followed this up with several major inquiries. One inquiry was overseen by an independent clinician who examined the timeliness and appropriateness of the responses to the events. A second inquiry looked at the systems in place to monitor vaccine adverse events. A third inquiry looked into the vaccine manufacturing and quality issues. These separate inquires continued for months and in one case extended for more than a year. They concluded that a manufacturing anomaly had caused the vaccine batch for that year to be more 'reactive' than usual and to provoke more adverse effects. As a result, flu vaccine made by this manufacturer was banned from use in children, while products from other manufacturers continued to be allowed to be used. The other inquiries found that vaccine event monitoring and responses could have been better, and that information sharing had been poor and could be improved.

The recommendations from these inquiries were accepted by the Australian government, which has started to implement new vaccine monitoring and oversight systems. China could learn much from the Australian response to a series of vaccine related adverse events, to improve vaccine safety monitoring and response systems and to improve transparency in the whole process.
A clear and open response on the issue is needed from the Chinese authorities to maintain confidence in the safety of vaccination programs for children. It is not enough to point out that 15 million children receive the hepatitis B vaccine each year with the vast majority showing no ill effects and that the vaccine program prevents millions of cases of severe illness and death. Given the previous food and drug quality safety scandals seen in China - and the lack of public faith in the responses from the authorities - it is not surprising that there is now a crisis of confidence in the quality of China's food and drug products. Let us hope that vaccines do not become like milk powder, with parents only having faith in imported foreign brands for their newborns.

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