5 facts about vaccines in the United States

Numerous measles epidemics across the United States have reignited the debate over whether parents should be required to vaccinate their children. Some parents worry that vaccines may harm their children, but the scientific consensus on the safety of the measles, mumps and rubella (MMR) vaccine remains high and surveys have shown that most Americans consider vaccines for children are beneficial.

In recent weeks, legislators in several states that have experienced an epidemic have proposed a bill to remove or restrict the types of exemptions that parents can claim for their children because of their religious or personal beliefs.

Here are some of the main conclusions of our research on attitudes towards childhood immunization:

1Most Americans believe that the benefits of MMR vaccine are high and the risks are low. In a survey conducted in 2016, 73% of US adults reported that the benefits of MMR vaccine for health were high, while 66% felt the risk of side effects was low. Overall, 88% said the benefits of MMR outweighed the risks, while 10% said the risks outweighed the benefits.

2About eight in ten Americans support school-based vaccines. Some 82% of US adults said the MMR vaccine should be mandatory "to be able to attend public schools because of the potential risk to others when children are not vaccinated". In addition, 17% of Americans believe that "parents should be able to decide not to vaccinate their children, even if this could lead to risks to the health of other children and adults. The majority of Americans in demographic and educational groups supported the school criteria for the MMR vaccine, although older adults are more likely than their younger counterparts to say that vaccinations should be recommended. needed to go to school (90% of adults 65 and over versus 77% of 18-49 year olds).

3A majority of American adults rely heavily on medical scientists for information on vaccines. In 2016, about 55% of Americans said they trusted scientists to provide complete and accurate information on the health risks and benefits of MMR for children. Thirty-five percent said they trust medical scientists, while only 9% said they trust neither too much nor at all. High confidence levels in the other groups, however, were much lower. For example, no more than one in ten Americans had much confidence in elected officials (6%) and the media (8%) to provide accurate information about the MMR vaccine.

4People unfamiliar with science are also less likely to find that vaccines have significant health benefits. While 91% of people with high scientific knowledge said that vaccines offered great health prevention benefits, only 55% of those with limited scientific knowledge agreed. In addition, those with little scientific knowledge were more likely to consider the risk of side effects as medium or high (47% versus 19% of those with high scientific knowledge). Americans who do not correctly recognize the definition of "group immunity" are less likely to attribute a high value to the benefits of the MMR vaccine and are relatively more likely to perceive the risk of at least moderate side effects. (Herd immunity refers to the health benefits that occur when most people in a population have been vaccinated.)

5State legislators are considering amending immunization laws. All 50 states and the District of Columbia require students to be vaccinated to attend school. However, each state and district allows children to give up immunization for medical reasons. States also grant derogations based on religious or philosophical convictions. As of July 2016, 46 states had granted exemptions based on religious beliefs, and 17 states had granted philosophical exemptions to people who opposed immunization for personal or moral reasons.

Lawmakers from at least 11 states have introduced legislation to limit or eliminate non-medical exemptions, according to the National Conference of State Legislatures. An Oregon bill aims to completely remove non-medical exemptions. When it was passed, Oregon would become the fourth state to ban non-medical exemptions, joining California, Mississippi and West Virginia. On the other side of the issue, lawmakers in at least nine states have proposed legislation to expand access to vaccine exemptions, based on a project analysis. proposed legislation to state legislatures in 2019. In addition, proposals in at least 10 states would require: health care providers to provide patients with information about vaccines before administering them.

Note: This is an update of an article originally published on July 17, 2015. The original version of this article was written by Monica Anderson, Senior Researcher specializing in Internet domains and technology at the Pew Research Center.