The measles outbreak and vaccine controversy, visualized
More than 100 people in 15 states were diagnosed with measles in January, with 92% of the cases related to an outbreak that began before Christmas at Disneyland in California.
Growing numbers of parents in recent years have skipped or delayed recommended vaccinations for their children, a trend that has led to a resurgence of measles. USA TODAY's Liz Szabo explains why routine shots have become so controversial.
Q: Why are some parents choosing not to vaccinate?
A: Many parents are concerned that vaccines can cause autism, a belief that originated with a now-discredited 1998 study, which has circulated on the Internet and has been promoted by some celebrities. The British journal that published the study, "The Lancet," retracted it in 2010. British medical authorities found the author, Andrew Wakefield, guilty of serious misconduct and stripped him of the ability to practice medicine in 2010 after finding that he had accepted $675,000 from a lawyer who was hoping to sue vaccine makers.
Q: What does science say about vaccine safety?
A: Vaccines are extremely safe, says Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. Fourteen scientific studies have found no link between measles vaccines and autism. Seven have found no link between autism and thimerosal, a preservative no longer used in childhood vaccines. And two studies have failed to find any link between autism and the number of vaccines a child gets.
Q: How has the controversy affected vaccination rates?
A: Nearly 40% of parents of toddlers have skipped or delayed a childhood vaccination, a 2010 study found. Measles vaccination rates vary greatly by state. Nearly 100% of kindergarten students in Mississippi have had both recommended doses of measles vaccine, but only 82% of Colorado children that age are fully vaccinated against measles, according to the Centers for Disease Control and Prevention.