Baby Who Had Stroke After Chicken Pox Shows Why We Need Vaccinations, Doctors Warn

The case of a healthy 11-month-old baby who suffered a stroke serves as a stark reminder of the importance of vaccines, doctors warned.

The unnamed baby's mother took the infant to see a doctor after she noticed weakness in his right arm and leg when he woke up from his usual afternoon nap, wrote the authors of a case study published in the Journal of Pediatrics.

Tests revealed the baby had suffered a stroke. Two to three months before, the baby and his older siblings, both of whom were unvaccinated, contracted chickenpox. Doctors believe a complication of the chickenpox virus brought on the stoke.

Chickenpox, caused by the varicella-zoster virus, a member of the herpes virus family of diseases, is highly contagious. A rash can appear first as raised pink or red bumps and erupt into up to 500 itchy blisters that cover the entire body. Other symptoms, which may precede the rash by one to two days, include fever, feeling tired, a loss of appetite and headache. These symptoms can linger for between five and seven days.

According to the Centers for Disease Control and Prevention, the best line of defense against chickenpox is vaccination. The CDC recommends children receive two doses of the chickenpox vaccine, the first at 12 to 15 months old, and the second at 4 to 6 years old.

A 2014 study by scientists at the London School of Hygiene and Medicine, which was cited in the Pediatrics study, found that the risk of stroke in children in the first six months of contracting chickenpox increased fourfold in children who had not been vaccinated, compared with zero risk in vaccinated children. It concluded that chickenpox was a risk factor for stroke in the first six months following infection, particularly in children.

Dr. Tina Tan, a professor of pediatrics at Northwestern University's Feinberg School of Medicine and a pediatric infectious disease specialist at the Robert H. Lurie Children's Hospital, told NBC affiliate KMIR that chickenpox was widely regarded as a minor illness, but it could cause "a number of serious complications"— including stroke in rare cases.

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She explained: "Basically, the chickenpox virus infects the large blood vessels in the brain and causes inflammation in them.

"The blood vessels can scar and that can decrease blood supply to the brain, which can lead to stroke." Depending on which blood vessels are affected, chickenpox complications can lead to permanent disabilities, such as paralysis or seizure disorders.

Vaccines don't just protect individuals who get the shot, but those around them—including children too young to be vaccinated, such as the baby in this case—and people with weak immune systems who are more vulnerable to disease.

Contrary to what the vocal minority of anti-vaccine campaigners attest, vaccines carry minimal risks, Dr. Aaron Milstone, associate professor of pediatric infectious diseases and epidemiology at the Johns Hopkins Health System, told KMIR. But as vaccines have almost consigned the memories of the serious complications infectious diseases can cause to history, parents can forget how important they are, he said.