Flu Vaccine Linked to GBS

Released today:

Nov. 13 (Bloomberg) — Vaccines against influenza that the
U.S. government is pushing to cut annual deaths and prepare for a
possible pandemic may be linked to slightly higher rates of a
paralyzing nerve disorder, a study found.
Patients with the disorder, called Guillain-Barre syndrome,
were more likely to have been diagnosed in the seven weeks after
vaccination than in a comparison period four to six months later,
Canadian researchers said in today’s issue of the Archives of
Internal Medicine.
The results of the study are consistent with earlier
research on flu vaccine, and won’t change federal
recommendations, said Jeanne Santoli, a vaccination expert with
the U.S. Centers for Disease Control and Prevention, in a
teleconference today. Federal officials are encouraging the
production and use of flu shots to cut an estimated 36,000 deaths
and more than 200,000 hospitalizations each year from influenza.
“The risk is real. You don’t want to have this blindside
you,” said Canadian researcher David Juurlink, who led the
study, in a telephone interview, “But the benefits of
vaccination are really substantial.”
Sanofi-Aventis SA, GlaxoSmithKline Plc, Novartis AG and
MedImmune Inc. make flu vaccine for the U.S. market, based on
strains that public-health officials identify each year as the
most common currently circulating. The CDC has expanded its
guidelines for flu vaccine in recent years, and the agency now
recommends immunization for almost two-thirds of Americans.
While the risk of Guillain-Barre is so small that rates of
the disease didn’t increase when a vaccination program began in
Ontario, patients should be informed, Juurlink said.

Ontario Program

Increasing flu vaccine use will also help the U.S. prepare
for mass immunizations in the event of a worldwide outbreak of
lethal flu, which government health officials have said is
inevitable.
Ontario began a universal flu vaccination program in 2000
after a severe outbreak the previous year overloaded hospitals
with patients. The program also presented flu experts with a way
to examine suspected complications of the vaccine, such as
Guillain-Barre.
Concerns about the mysterious, paralyzing disorder, which is
usually temporary, arose in 1976 during an outbreak of the so-
called swine flu that U.S. health officials warned might cause a
pandemic. While the pandemic never materialized, the link raised
long-standing fears about the safety of flu vaccine.
A 1998 study in the New England Journal of Medicine found
that flu vaccination raised the risk of Guillain-Barre 70
percent. However, a 2003 review of other studies by the U.S.
Institute of Medicine, the agency that creates volunteer expert
panels to advise the government on health issues, found no
association between Guillian-Barre and seasonal flu vaccination.

Timing

Juurlink, a researcher at Canada’s Institute of Clinical
Evaluative Sciences in Toronto, and his team found 269 patients
diagnosed from April 1992 through March 2004 who developed the
nerve disease within a six-month period after vaccination.
Patients were 45 percent more likely to develop the disease in
the first two months after vaccination than in the fifth and
sixth months, the researchers said.
Ontario also had begun a large immunization program against
pneumococcal disease, a bacterial infection, that may have been
responsible for some complications, said David Fedson, a former
vaccine developer and University of Virginia professor of
medicine, in an e-mailed response to questions.
“The association is there,” with flu vaccine, Fedson said,
“but the increase in risk is very small.”

Benefits, Risks

Young children and people who are at least 65 years old are
at highest risk of complications from flu vaccination. More
studies in these age groups, along with teens and young adults,
are needed to show the benefits of vaccination against potential
risks, he said.
“Only in this way can people balance the benefit and risks
of vaccination,” he said.
Juurlink said he would continue to recommend vaccination for
his patients and family.
“It’s a no-brainer,” he said. “Literally tens of
thousands of Americans don’t get hospitalized or die each year
because they’ve had flu vaccine, and to me it’s worth the trade-
off.”