Vaccines reduce risk of strokes in children

Kids who were unvaccinated or undervaccinated were almost seven times as likely as others to have a stroke, a new study finds.

A new international study finds another benefit to childhood vaccines: preventing strokes.

Pediatric strokes are rare, affecting about five out of every 100,000, for about 5,000 pediatric strokes a year in the USA, says co-author Heather Fullerton, a professor of neurology and pediatrics at the University of California, San Diego. About half of these strokes are caused by blood clots, the focus of her study.

In the study, which included children in the developing world, kids who received "some, few or no" vaccines were nearly seven times more likely to have a stroke than kids who had all or most of their recommended shots, according to Fullerton's research, presented at the American Stroke Association's International Stroke Conference in San Diego.

Previous research has shown that infections greatly increase a child's risk of stroke, partly by causing a temporary increase in the blood clotting, Fullerton says.

Several vaccine-preventable bacterial diseases – such as those caused by the bacteria pneumococcus or Haemophilus influenzae type b, or Hib — can lead to meningitis, an inflammation of the lining of the brain and spinal cord that also increases a child's risk of stroke, she says.

Vaccines have been hailed as one of medicine's greatest success stories, and have eliminated a host of deadly diseases from the USA.

While some strokes are related to genes, doctors still don't understand what causes many childhood strokes, said Fullerton's co-author, Nancy Hills, also of the University of California, San Francisco, in a statement. She said she's encouraged to find a way to reduce children's risks.

"The exciting thing about this study is that with vaccination, it might prevent these strokes from happening," says neurologist M. Shazam Hussain, director of the stroke center at the Cleveland Clinic, who was not involved in the new study.

Robert Brown, chair of neurology at the Mayo Clinic College of Medicine in Minnesota, called the study's findings "remarkable," noting that study was large and well-designed.

"To lower the risk of stroke is noteworthy," Brown says. And while strokes in children are rare, "these are precious young children who are having these strokes, which affect them throughout their long, long lives."

Researchers presented their work in abstract form. It has not yet been published as a full paper in a peer-reviewed journal.

Leaders of the international study, Vascular effects of Infection in Pediatric Stroke, or VIPS, interviewed the parents or guardians of 310 children who had a stroke, and compared their findings with 289 children who hadn't experienced a stroke. Kids in both groups were around 7.5 or 8 years old. The study, which included 40 centers on five continents, is the largest study on pediatric stroke ever funded by the National Institutes of Health.
(Source: usatoday.com)