Skip to content

    Children's Vaccines Health Center

    Font Size

    Refusing to Vaccinate Affects Other Kids, Too

    Study: Vaccine Refusal Fueled San Diego Measles Outbreak
    WebMD Health News
    Reviewed by Louise Chang, MD

    March 22, 2010 -- A CDC investigation shows a measles outbreak in San Diego was fueled by kids whose parents refused to vaccinate them, thus endangering children too young to be vaccinated.

    Measles is one of the world's most highly contagious viral diseases. Thanks to high vaccination rates, the dangerous disease stopped circulating in the U.S. But now there are ominous signs it may come back.

    The reason: Pockets of parents who believe the measles/mumps/rubella (MMR) vaccine is more dangerous than the diseases. Such beliefs led to a drop-off in MMR vaccination in England -- and the subsequent return of measles.

    Could it happen in the U.S.? Yes, suggests an in-depth study of the 2008 measles outbreak in San Diego.

    San Diego Measles Outbreak

    The outbreak began in January 2008 when a 7-year-old boy whose parents refused to vaccinate him returned to the U.S. from Switzerland. Before symptoms appeared, he infected his 3-year-old brother and 9-year-old sister. Neither was vaccinated.

    Neither were 11% of the boy's classmates, whose parents shared similar beliefs that a healthy lifestyle protected against disease while vaccines were riskier than the illnesses they prevented.

    In the end, 839 people were exposed to measles. Eleven were infected, and 48 exposed kids too young to be vaccinated were quarantined -- forbidden to leave their homes -- for 21 days. Jane Seward, MBBS, MPH, was the CDC's senior investigator for the outbreak.

    "Even with the very high vaccine coverage that we saw in San Diego, if you have a community of vaccine refusers you can get an outbreak," Seward tells WebMD. "Had the local health department not been extremely aggressive in quarantining everyone who came in contact with a case who did not have immunity, the outbreak would have broadened."

    Fortunately, nobody died or suffered neurological damage. But there was one very close call.

    Megan Campbell's 10-month-old son was in the pediatrician's waiting room when the boy who'd been infected in Switzerland came in. The infant got very, very sick -- so sick that Campbell and her family thought he was going to die.

    1 | 2 | 3

    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