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
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
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