Among his first acts as President-elect, Donald Trump signaled his interest in establishing a presidential committee on vaccine safety and scientific integrity, headed by Robert Kennedy Jr., a lawyer known for arguing that a preservative used in some vaccines causes neurological disorders. This is a position at odds with the Centers for Disease Control and Prevention and other organizations which evaluate the safety of childhood vaccines.

Credit: Pew Research Center

A new Pew Research Center survey conducted during the campaign finds such “vaccine hesitant” views to be at odds with most Americans’ beliefs. An overwhelming majority of Americans consider the benefits of the measles, mumps and rubella vaccine to outweigh the risks (88 percent to 10 percent who say the risks outweigh the benefits). Some 73 percent of Americans rate the preventive health benefits of the MMR vaccine as high and 66 percent rate the risk of side effects to be low.

Public concerns about the safety of the MMR vaccine have been percolating since at least 1998 when a research study – later discredited –suggested that MMR vaccines were associated with autism. The new Pew Research survey shows that those with more concern include parents with young children, a group directly faced with decisions about how to protect their children from the risk of disease.  The survey finds 52 percent of parents with children ages 0 to 4 say the risk of side effects from the MMR vaccine is low, while 43 percent of this group says the risk is medium or high. By comparison, 70 percent of those with no minor age children say the risk of side effects is low, 29 percent say the risk is medium or high.

It is important to note that in a highly polarized era, Republicans and Democrats (including those who lean to either party) hold roughly the same views about the preventive health benefits and risk of side effects from the MMR vaccine. Further, there are no differences or only modest ones across the major religious groups in perceptions of the risks and benefits from the MMR vaccine.

Reports that significant numbers of high-income parents have not immunized their children lead some to speculate that people with higher incomes have more concerns about the safety of the MMR. The survey finds, however, that people with higher family incomes tend to rate the risk of side effects from the MMR vaccine as low.

But several other groups of Americans join parents of young children in seeing higher risk from the MMR vaccine. Such concerns can have outsized consequences to the extent that people’s views influence their immunization behaviors, since the collective health benefits which accrue from “herd immunity” require high levels of immunization across all communities.

Credit: Pew Research Center

Blacks are more likely than whites, on average, to think there is at least a medium risk of side effects from the MMR vaccine (44 percent of blacks vs. 30 percent of whites). On the flip side, blacks are also less likely to rate the preventive health benefits of the MMR vaccine as high; 56 percent do so compared with 79 percent of whites.

The 8 percent of Americans who report never using over-the-counter medications for cold or flu symptoms, for example, are especially likely to see medium or high risk from MMR vaccines (49 percent compared with 31 percent of those who take over-the counter medications either right away or if their cold or flu symptoms worsen). And, Americans who have used alternative medicine instead of conventional medical treatment are more inclined to think the risk of side effects from the MMR vaccine is medium or high (43 percent compared with 30 percent of those who have never used alternative medicine or have done so in conjunction with conventional medicine).

People with low knowledge about science (based on a 9-item index of questions about a range of science topics) are closely divided in their assessment of risk from the MMR vaccine; 50 percent say the risk of side effects is low and 47 percent say the risk is at least medium. By contrast, 79 percent of those high in science knowledge say the risk of side effects is low, 19 percent say it is at least medium. Some 55 percent of those with lower science knowledge rate the preventive health benefits as high, compared with 91 percent of those with higher science knowledge.

While public health specialists pay particular attention to the behaviors of parents of young children, parents are likely to have a differing set of underlying reasons for their comparatively higher levels of concern about the MMR vaccine than are blacks, those low in science knowledge, and those who have used alternative medical practices.