WEDNESDAY, March 13 (HealthDay News) -- People who were vaccinated against the 2009 H1N1 swine flu virus had a slightly increased risk of a paralysis disorder, according to a new study, but the benefits of vaccination greatly outweighed the risks.
Researchers analyzed data from 23 million people in the United States who received the vaccine during the 2009 outbreak -- the largest mass vaccination in recent U.S. history -- and found that they had a small excess risk of developing Guillain-Barre syndrome.
The disorder of the nervous system results in temporary or longer-term paralysis, and sometimes causes death.
The researchers found that 77 people developed Guillain-Barre syndrome up to 91 days after receiving the H1N1 vaccine. They concluded that there were 1.6 excess cases of Guillain-Barre syndrome in every 1 million people vaccinated, according to the study, which was published online March 12 in the journal The Lancet.
About 61 million cases of H1N1 swine flu were reported in the United States during the 2009 pandemic, including about 274,000 hospital admissions and more than 12,000 deaths. H1N1 vaccines offered substantial protection, said study leader Dr. Daniel Salmon, of the National Vaccine Program Office at the U.S. Department of Health and Human Services.
Salmon said a recent study estimated that the H1N1 vaccination program prevented between 700,000 and 1.5 million cases of flu, between 4,000 and 10,000 hospital admissions, and as many as 500 deaths. Health care professionals, lawmakers and patients "should be assured that the benefits [of vaccination] greatly outweighed the risks," Salmon concluded in a journal news release.
Guillain-Barre syndrome usually follows a viral or bacterial infection. Although it is a serious condition from which patients typically take months to recover, about 80 percent have a full recovery with appropriate treatment.
The U.S. National Institute of Neurological Disorders and Stroke has more about Guillain-Barre syndrome.
-- Robert Preidt
SOURCE: The Lancet, news release, March 12, 2013
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