Guillain-Barré risk same for H1N1 and seasonal flu shot
■ A preliminary report from the CDC puts the chance of contracting the neurological disorder far lower than for the 1976 swine flu vaccinations.
People who received the 2009 influenza A(H1N1) vaccine had nearly the same risk of contracting Guillain-Barré syndrome as did those immunized against the seasonal flu, the Centers for Disease Control and Prevention said.
Preliminary data indicate fewer than one excess case of the neurological disorder for every 1 million people vaccinated against H1N1, according to a study in the CDC's June 4 Morbidity and Mortality Weekly Report (link).
Seasonal flu vaccine yielded similar results, with about one excess case of Guillain-Barré in a million people immunized.
"We conducted a very large surveillance for Guillain-Barré syndrome ... and we found that in respect to [GBS], the H1N1 vaccine seems just as safe as the seasonal flu vaccine. There's no reason to believe they're different," said Oliver Morgan, PhD, a CDC epidemiologist who led the analysis for the report.
Researchers examined data from a population sample of about 45 million children, adolescents and adults from Oct. 1, 2009, to May 10, 2010, using the CDC's Emerging Infections Program. The program is a network that compiles vaccine data of 10 state health departments, as well as academic institutions, local health departments, federal agencies and health professionals in those states.
Morgan said there was no clustering of Guillain-Barré cases among the immunized, unlike in 1976. That year, there were approximately 10 cases of Guillain-Barré for every 1 million people immunized, according to the CDC. Dozens of cases broke out during a vaccination campaign for what was then called swine flu. Ultimately, the government decided to end the immunizations.