The CDC advises that children be vaccinated against a variety of common harmful diseases. Numerous studies show that these routine shots don’t cause autism, as was once suspected. And thimerosal, the mercury-based ingredient suspected of causing problems, was removed from vaccines in 2001. Yet controversy persists, and some parents refuse to vaccinate their little ones.

But rejecting the needle today can carry consequences tomorrow. Consider these outbreaks: five cases of bacterial infection haemophilus influenzae in Minnesota and 131 cases of measles spanning 15 states in 2008 alone. More than 90 percent of those who contracted measles hadn’t been vaccinated.

Take it from a doctor: Meg Fisher, MD, of the American Academy of Pediatrics, says, “Vaccines are actually the most tested of all products that we use in medicine. The vaccines are incredibly safe—but the diseases they’re developed to prevent aren’t.”