Flu Shot May Offer Protection.(Brief Article)

2002 FEB 13 - (NewsRx.com & NewsRx.net) -- The flu vaccine may offer significant protection against stroke, especially for people age 75 or younger, researchers in France report in the February 2002 issue of the journal Stroke.

This is the first study to look at the influenza vaccine's influence on stroke. Prior research has shown that infections are associated with stroke and heart attack, possibly because they destabilize atherosclerotic plaque and cause clots in arteries that supply blood to the brain and heart. Clots blocking blood flow to the brain can cause a stroke. If an artery to the heart is blocked, it causes a heart attack.

"Since subjects who have viral influenza can develop subsequent infections, we thought that flu vaccination may mean less infection overall and, therefore, less stroke," says Pierre Amarenco, MD, one of the study's authors. "We found the reduction in stroke risk to be around 40% for those who were vaccinated, which would be a major advance in stroke prevention if further studies confirm these results."

Amarenco is a professor of neurology at Denis Diderot University and chairman of the department of neurology and stroke center at Bichat Hospital in Paris.

Researchers studied 270 people. They interviewed 90 patients age 60 and older who were admitted to a stroke clinic between December 1998 and March 1999 and between January and March 2000. For each stroke survivor, researchers also interviewed two age-, sex-, and geographically matched control subjects (180 total).

The researchers asked patients and controls whether they had been vaccinated against influenza during the most recent vaccination drive (which is October in France) and if they had been vaccinated every year for the previous 5 years. The subjects were asked whether they had been treated with antibiotics in the previous 3 months and if they suffered from chronic bronchitis.

Amarenco and colleagues also gathered participant data about risk factors for stroke including age, gender, hypertension, diabetes mellitus, high cholesterol, current smoking, and body mass index. They asked subjects if they had taken at least one blood cholesterol test, if they had a history of stroke or heart disease, and about their occupations (to divide them into white- and blue-collar categories).