By RJ Reinhart

Widespread public support for childhood vaccines creates a wall preventing contagious diseases like measles and polio from spreading in the U.S., but a breach in that wall appeared in 2015 and it has not been repaired. A recent Gallup survey finds 84% of Americans saying it is extremely or very important that parents vaccinate their children. That matches Gallup's prior reading in 2015 but is down from 94% in 2001.

The decline in Americans' belief in the importance of vaccinating children between 2001 and 2015 occurred among almost all subgroups of the U.S. public. Since then, attitudes have been fairly flat by gender, age, education and party ID.

The only group that has maintained its 2001 level of support for vaccines is highly educated Americans, those with postgraduate degrees. Ninety percent of this group says vaccination is important, essentially unchanged from the 92% in 2015 and 2001. Perceptions of the importance of vaccination declined by at least five percentage points among all other education subgroups.

Broad majorities of Americans also report that they are aware of the advantages and disadvantages of vaccines. Nearly nine in 10 (89%) say they have heard "a great deal" or "a fair amount" about the advantages of vaccinations, up from 83% in 2015 and 73% in 2001. Meanwhile, 79% say they have heard a great deal or a fair amount about the possible disadvantages of vaccines. This is up modestly from 73% in 2015, though it reflects a substantial increase from 39% in 2001.

While many opponents of vaccinations argue that vaccines are more dangerous than the diseases they prevent, the vast majority of Americans, 86%, continue to disagree. This is unchanged from the 87% who felt that vaccines were less dangerous in 2015 and only modestly lower than the 90% in 2001. Currently, 11% of U.S. adults think vaccines are more dangerous than the diseases they prevent.

The opinion that vaccines are safer than the diseases that they prevent stayed the same or declined modestly among most subgroups in the U.S. between 2001 and 2015. However, the percentage of Republicans confident in their benefit has fallen slightly, from 91% to 85%. At the same time, Democrats' confidence in the value of vaccines is essentially unchanged.

Although the vast majority of Americans see vaccines as less dangerous than the diseases they prevent, fewer, 62%, say the government should require all parents to have their children vaccinated. This is down from the 81% who said the government should require vaccination in a 1991 Princeton Survey Research Poll.

Perhaps the most well-publicized and debunked claim of danger posed by vaccines is that they cause autism. Currently, 10% of U.S. adults believe vaccines cause autism in children, marking a modest increase from 6% in 2015. Nearly half, 45% do not think vaccines cause autism, up modestly from the 41% who said the same almost five years ago. And 46%, down from 52%, say they are unsure.

The more advanced an American's formal education, the more likely they are to say vaccines do not cause autism. The figure is 73% among those with postgraduate education, falling to 61% among those with a college degree only, 42% of those with some college and 28% of those with no college experience. Importantly, lesser-educated Americans are much more likely to have no opinion than to say they believe vaccines do cause autism. The percentage making the causal connection tops out at 12% among Americans with no college education, versus 5% of postgraduates.

There are also substantial partisan differences, with 55% of Democrats saying vaccines do not cause autism, compared with 37% of Republicans.

The science is clear: Vaccines are safe, and having children vaccinated is both important and confers vast benefits for them. Generally, large majorities of Americans agree with scientists. However, there is enough uncertainty among the public concerning a potential link between autism and vaccines that compliance with pediatric vaccine recommendations could drop and threaten what's known as "herd immunity." Herd immunity is where a sufficiently large percentage of the population, typically in excess of 93%, is vaccinated, ensuring that even those who cannot be vaccinated for medical reasons are protected from these diseases.

Pro-vaccine public awareness campaigns appear to be working to the extent that more Americans -- now a majority for the first time -- report having heard a lot about the medical advantages of vaccines for children. However, more have also heard about the disadvantages. While they are not as pervasive and are being exposed as untrue, these counterarguments are still getting through, perhaps explaining why public support for vaccines remains lower than at the start of this century.

Source: Gallup