While most Americans are on board with vaccinating their children against measles, mumps, and rubella, parents of younger kids are unclear on the benefits vs. risks.

baby getting vaccine shot in thigh
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According to a new survey from the Pew Research Center, most Americans are generally on board when it comes to getting heir kids vaccinated for measles, mumps and rubella (MMR). But parents of young children are less convinced of the vaccine's health benefits and safety.

Researchers polled more than 1,500 Americans ages 18 or older, and found that while 88 percent of those surveyed agreed that the benefits of the MMR vaccine outweighed any risks, parents with children ages 4 or younger—who have recently faced or will soon face the decision of whether to follow the recommended immunization schedule for MMR starting when their children are between 12 and 15 months old—were more concerned about the potential risk of side effects.

Sixty percent of those parents viewed the preventive health benefits of the MMR vaccine as high, compared with 75 percent of parents with school-age kids (ages 5-17) and 76 percent of people with no children at all under the age of 18. About half of parents with children ages 4 and younger felt the risk of side effects from the MMR vaccine was low, while 43 percent said it was medium or high. By comparison, 70 percent of those without minor-age kids said the risk of side effects was low, and only 29 percent felt it was medium or high.

In addition to parents of young children, lead author Cary Funk says the analysis found other groups with concerns as well. For example, those who identified as black considered the risk of side effects from the vaccine to be higher and the benefits lower than those who identified as white. Adults under age 30 were less convinced of the vaccine's high preventive health benefits—as were those with low knowledge of science. And people who reported never taking over-the-counter cold or flu medications and those who had used alternative meds were more wary of the vaccine's side effects.

Still, Funk says that overall public perceptions of the benefits of the MMR vaccine are strongly positive, with 73 percent of adults rating the preventive health benefits as high, and only one-in-10 reporting they are outweighed by the risks. Which makes sense, considering the MMR vaccine has been proven time and again to be safe and effective. Research has shown that, despite persistent rumors, there is no connection between the vaccine and autism. In terms of side effects, up to 17 percent of kids may experience a fever after the shot, and maybe 5 percent will get a rash. In very rare cases, some people may experience swelling of the cheecks or neck, febrile seizures, or temporary joint pain. However, contracting measles, mumps, or rubella is much more dangerous than any side effect of the vaccine, as the most severe cases can cause things like permanent hearing loss, brain damage, and even death.

Since the vaccine became available in the 1970s, the diseases all but disappeared in the U.S. However, outbreaks can and still do happen, usually because of some children skipping immunizations, says Neal Halsey, M.D., director of the Institute for Vaccine Safety at the Johns Hopkins University Bloomberg School of Public Health in Maryland. "In order to prevent other future outbreaks—and keep our children healthy—it's crucial that we continue to get our kids vaccinated against these diseases completely and on time."

Hollee Actman Becker is a freelance writer, blogger, and mom of two who writes about parenting and pop culture. Check out her website holleeactmanbecker.com for more, and then follow her on Instagram and Twitter.