Massive study in China shows no connection between 2009 H1N1 immunization and rare nervous system disorder
Any speculation drawing an ongoing link between flu vaccination and the risk of a rare, paralyzing neuromuscular disorder has been dashed by a huge study. An analysis of side effects recorded among nearly 90 million people in China who were vaccinated during the 2009–2010 flu season found that only 11 people subsequently were diagnosed with Guillain-Barré syndrome, a rate no greater than what normally appears in the population. The study appears online February 2 in the New England Journal of Medicine.
In 1976, a strain of swine flu showed up in the United States, prompting the manufacture and delivery more than 40 million doses of vaccine against it. The epidemic ultimately never materialized, but studies noted that hundreds of cases of Guillain-Barré syndrome were reported after the vaccination campaign. The vaccine was withdrawn. In 2003, an Institute of Medicine review found that the evidence pointed to an association between the 1976 swine