Hexavac withdrawal

The withdrawal of the vaccine Hexavac® by the European Medicine Agency (EMEA), in September 2005, caused surprisingly few reactions. EMEA’s reason for withdrawal (lack of efficacy) is questionable: early post-marketing period is usually not devoted to efficacy re-assessments, whereas the last public statement on Hexavac (Dec 2003) was related with a safety problem (sudden infant death syndrome [SIDS]). An additional comment from the French Agency (the alleged problem of efficacy could come from variations in the manufacturing process) is frankly disturbing, concerning one major firm normally viewed as a crucial safeguard in case of bioterrorism or avian flu, and which already has the worrying record of selling in France a hepatitis B vaccine (Genhevac®) the dossier of which was apparently never assessed a sufficient to justify registration in any other developed country.

Within the same time, Zinka et al (1) published an impressive series of six SIDS after Hexavac injection and reported various extrapolations suggesting a minimum 500% increase of cases in a country like Germany: these figures are credible, since the scientific discussion on Hevaxax published on the EMEA site when the product was registered mentioned 7 cases of SIDS among 3 905 infants included in the development studies and followed for safety during a 1-month period, which corresponds to a 35-fold increase as compared to the expected number over a similar period…

A rapid calculation suggests that the presumed small decrease in efficacy claimed by EMEA would have, at worst, accounted for less than one case/year of complicated hepatitis in countries like Germany or France; in contrast, available evidence already shows that the potential of SIDS could have accounted for dozens or even hundreds of deaths each year within the same countries. It is therefore difficult to grasp the hierarchy of health priorities adopted by European agencies: having regard to the precedent of tolcapone (Tasmar®), this is not the first time…

Competing interests : Dr Girard works as an independent consultant for pharmaceutical industry, including vaccine manufacturers and a number of their competitors.

References

1. Zinka B, Rauch E, Buettner A, Rueff F, Penning R. Unexplained cases of sudden infant death shortly after hexavalent vaccination. Vaccine 2005 May 18.