Saturday, July 23, 2011

European Medicines Agency confirms that Pandemrix vaccine caused narcolepsy/ EMA

According to the European Medicines Agency press release:
The Committee for Medicinal Products for Human Use (CHMP) considered that the epidemiological studies relating to Pandemrix in Finland and Sweden were well designed and the results show an association between Pandemrix vaccination and narcolepsy in children and adolescents in those countries. The results indicate a six- to 13-fold increased risk of narcolepsy with or without cataplexy in vaccinated as compared with unvaccinated children and adolescents, corresponding to about an additional three to seven cases in every 100,000 vaccinated subjects. This risk increase has not been found in adults (older than 20 years). A similar risk has not been confirmed but cannot be ruled out in other countries.
The Committee noted that the vaccine is likely to have interacted with genetic or environmental factors which might raise the risk of narcolepsy, and that other factors may have contributed to the results. There are several initiatives being developed across the EU to further investigate this association....
All illnesses occur due to a complex mix of environmental exposures and genetic predisposition.  Had the adverse effect been Guillain-Barre Syndrome, for example, the same could be said.  In other words, the statement that the vaccine "is likely to have interacted with genetic or environmental factors which might raise the risk..." is a truism, which detracts from the seriousness of the vaccine adverse effect. 

Roughly 20% of the population has the HLA type that seems to be needed for narcolepsy,  Some people who have this HLA type get narcolepsy after vaccination, but most don't.  Therefore something else is needed to explain the onset of narcolepsy.

The bottom line is that vaccination increased narcolepsy cases by 6-13 times what would be expected without Pandemrix vaccination.  This is the same ballpark increase in incidence that the 1976 swine flu vaccine caused in Guillain Barre cases.

Since narcolepsy tends to have its onset around age 15 anyway, this was the age group in which most cases were found.  Although an increased risk was not found in the over 20 age group, this might simply be due to insufficient cases to make a statistical inference.

In any event, the vaccine is no longer recommended in the under-20 age group.

Next question:  is this serious adverse effect due to the novel ASO3 adjuvant that the vaccine contained, which had only been used in a small number of people previously?  This is the important question, and the one that has been dodged by EMEA and the press.  It is important because a number of new candidate vaccines not yet licensed include ASO3.  No other vaccines used for a mass audience contain ASO3.  [Cervarix HPV vaccine contains ASO4.]  Can our regulatory agencies please study the ASO3 issue before we use this product in human vaccines again?  Could FDA direct that it be studied in animal models?  Some dogs have a known genetic tendency toward narcolepsy and could serve as a good animal model.  They should be evaluated for their response to a) this adjuvant alone, b) to the H1N1 antigens alone, and c) to the Pandemrix vaccine.

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