A very large retrospective analysis performed by researchers affiliated with Kaiser-Permanente Northern California (KPNC) has confirmed what numerous prior studies have shown: there is no discernible link between influenza vaccine and the neurological condition, Guillain-Barre syndrome (GBS).
This study went beyond prior analyses, however, in two ways: first, the authors reviewed records from all KPNC vaccinated people between 1995 and 2006 comprising over 30 million person-years, a vast undertaking; and they also sought evidence of any detectable link between GBS and other vaccines, including those against tetanus, pneumococcus, diphtheria, typhoid, and hepatitis A and B.
There were none found. Thorough investigation of the 415 confirmed cases of GBS in that interval revealed no difference in vaccination exposure as compared to the millions without GBS.
A recent evaluation of the 2009 H1N1 swine flu vaccine recipients who were pregnant when vaccinated also found no evidence of adverse effect among moms-to-be nor in their offspring.
ACSH s Dr. Gilbert Ross added this perspective: Studies seeking evidence of serious reactions to common vaccines, especially neurological ones, continue to find none. The vaccines studies including flu, MMR, and DTaP, among others. We pointed this out not long ago when a report seeming to implicate flu vaccine in GBS was found to be baseless. In fact, using the best available statistics (difficult to do rigorously given how rare GBS is), the same report could be used to support a theory that flu vaccine actually protects against GBS. While this is certainly unlikely, it is no more so than saying flu vaccine, or any vaccine, causes it. It s too bad, indeed a dangerous myth and a tragedy, that the anti-vaccine advocacy groups are so adept at spreading falsehoods about vaccines. It will take many more such studies to convince concerned parents that vaccines have few risks and many benefits.