Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Children's Vaccines Health Center

Font Size

Delaying Measles-Related Vaccines: Seizure Risk?

Researchers say findings emphasize importance of following timing guidelines


To get answers to their questions, the researchers studied vaccination records of over 323,000 U.S. children from 2004 to 2008.

The timing of vaccinations during the first year of life didn't affect seizure rates. But delaying a measles-mumps-rubella immunization until 16 to 23 months boosted the risk of seizure from about 1 in 4,000 doses to 1 in 2,000 doses, Hambidge said.

For the vaccine that also wards off chicken pox, the rate grew from 1 in 2,000 doses to 1 in 1,000 doses, he said.

What's going on? It's possible, Hambidge said, that the immune systems of the older children are stronger, allowing them to develop fevers to fend off the weakened germs in the vaccines. The fevers can then lead to seizures.

Seizures in young children are common, said Dr. Geoffrey Weinberg, professor of pediatrics at University of Rochester School of Medicine and Dentistry in Rochester, N.Y.

"They occur in as many as 2 to 5 percent of children by age 5, most commonly at 16 to 18 months of age," Weinberg said. "They can be very scary and often result in medical care visits, but, for the vast majority, have no long-term effects."

Whatever the risk of seizures, Weinberg said it's important to get babies immunized on time so they'll be protected against measles, mumps, rubella and chicken pox. These potentially serious childhood diseases are very contagious.

As of May 9, 2014, 187 people in the United States have been diagnosed with measles this year, according to the Centers for Disease Control and Prevention. Dr. Anne Schuchat, director of the National Center for Immunization and Respiratory Diseases, said that's "the most measles cases reported in the first four months of the year since 1996." Most of those sickened hadn't been vaccinated.

1 | 2

Today on WebMD

Baby getting vaccinated
Is there a link? Get the facts.
syringes and graph illustration
Get a customized vaccine schedule.
baby getting a vaccine
Know the benefits and the risk
nurse holding syringe in front of girl
Should your child have it?

What To Know About The HPV Vaccine
24 Kid Illnesses Parents Should Know
Nausea and Vomiting Remedies Slideshow
Managing Immunization Schedules For Kids

Doctor administering vaccine to toddler
gloved hand holding syringe
infant receiving injection

WebMD Special Sections