Posted by Lucy Lazarony
A new study from the University of Lincoln in England shows the risk of suffering a stroke is greatly reduced for up two months after receiving a flu shot.
The study published in the journal Vaccine shows the risk of a first stroke is reduced by one-fifth in the first 59 days after taking the flu vaccine.
Flu Shots Reduce Stroke
Following a flu shot, there were:
• 36 percent fewer stroke cases in the first week
• 30 percent fewer stroke cases in the second week
• 24 percent fewer stroke cases in the third and fourth week
The study also found a 17 percent drop in stroke cases in days 29 to 59 after patients received a flu vaccine.
The biggest drop in stroke risk came in the first three days, when there was a 55 percent drop in stroke cases after patients received a flu shot.
The study looked at how the flu vaccine affected stroke risk in almost 18,000 patients, aged 18 and older.
Each patient in the study had suffered a first stroke between 2001 and 2009. And just over half of the patients in the study were women. All the patients received flu vaccines.
Researchers looked at how many strokes occurred within 180 days for patients receiving flu shots.
According to researchers, the earlier the vaccine was administered during flu season, the greater the protection for the patient against a first stroke. And patients that received the flu vaccine between Sept. 1 and Nov. 15, at the start of flu season, saw the greatest reduction in risk for strokes.
The findings support flu shots for people with high risk of stroke and encourage early vaccinations during flu season.
The specific study method used by researchers, a self-controlled case study, reduced the chances that the lowered stroke risk findings were caused by any other reason than the flu vaccinations that each patient received.
Researchers are looking to confirm the research findings in clinical studies.
Future studies may also determine how much a flu vaccine would lower stroke risk in younger adults.
Earlier studies have already linked flu vaccinations with a reduced risk of a heart attack as well as a first stroke.
Each year flu vaccinations are given to protect against the influenza virus and prevent respiratory complications such as pneumonia. Flu vaccines have a maximum effectiveness of six months.