The Medical Minute: A true or false quiz on vaccines

By Benjamin Levi

True or false:

1. Vaccines cause autism.

False. Study after study has failed to link autism and vaccines, says the American Academy of Pediatrics (AAP). The myth that vaccines cause autism stems from a 1998 study of the measles-mumps-rubella (MMR) vaccine. This study was later found to have serious flaws and its lead author to have had financial ties with a malpractice lawyer involved in suing vaccine manufacturers. As a result, all but two of its authors now agree it was wrong. Autism is often first identified when a child is 18 to 30 months old. Since the MMR vaccine is typically given just before that age, the myth about this link persists.

2. Vaccines have not wiped out common childhood illnesses.

True. Vaccines can have dramatic effects. After U.S. doctors began using the chickenpox vaccine in 1995, chickenpox cases fell 90 percent in 10 years. But chickenpox, measles, whooping cough and other deadly diseases are not gone. They’re just a plane ride away, says the Centers for Disease Control and Prevention (CDC). Travelers “import” them from overseas. When that happens, communities with lots of unvaccinated children face a higher risk of outbreaks.

3. Giving multiple vaccines at one time is likely to harm a young child.

False. Children need vaccines while they’re young and most vulnerable to serious illness. That’s why a child gets up to 23 immunizations by age 2—sometimes half a dozen at one visit. That may seem like a lot. But studies show it’s safe to give a child more than one vaccine in a visit, and typically they’re combined into just two or three actual shots. According to the AAP and the CDC, multiple vaccines work very well, don’t worsen side effects, and won’t harm a normal child’s immune system.

4. You can protect a child by getting vaccinated yourself.

True. Getting a flu shot while pregnant, for instance, helps protect your baby from the flu. One study found that babies born to moms who got a flu shot had a 63 percent lower risk of the flu than infants born to moms who didn’t get a flu shot. Children less than 6 months old can’t get a flu shot, so that extra protection is vital. You also can help protect your baby from whooping cough by making sure everyone around the infant has had a booster shot against this illness.

5. Kids get all the shots they need by their sixth birthday.

False. Some vaccines wear off over time. Around age 11 or 12, children need booster shots against tetanus, diphtheria, and whooping cough, the CDC says. Preteens also face disease threats such as meningitis, and a vaccine can thwart many cases of this illness. Preteen girls should be vaccinated against a virus that causes most cases of cervical cancer.

Penn State Hershey researcher and pediatrician, Benjamin Levi, says that “given what parents hear and see in the media it’s understandable that they worry about the safety of vaccines. But vaccines are enormously effective at protecting children from serious and potentially deadly infectious diseases, and are one of the best ways that parents can protect the health and wellbeing of their children.”

Dr. Benjamin Levi is an associate professor of pediatrics at the Penn State Hershey Children’s Hospital and in the Department of Humanities in the Penn State College of Medicine.