Governor Kim Reynolds and top Republican lawmakers have repeatedly bragged about protecting Iowans’ freedom not to get vaccinated for COVID-19, saying that getting a shot should be a matter of personal choice and not government mandate.

Now the latest Iowa Poll by Selzer & Co indicates that support for other required childhood vaccinations has dropped sharply since the last time Iowans were surveyed on the issue.

Republican respondents in particular are now less likely to support mandatory vaccinations against diseases like polio and the measles—a finding that suggests the misinformation campaign some have waged against COVID-19 vaccines has affected how many conservatives view all immunizations. When Selzer asked Iowans a similar question in 2015, there was no significant difference in views based on political affiliation.

Health care reporter Tony Leys wrote up the new findings for the Des Moines Register. The survey asked 813 Iowa adults, “Which of the following do you think is the best approach for Iowa law on childhood vaccinations other than for COVID-19?”

Just 34 percent said children should be required to get vaccines “unless they have a doctor-signed statement giving a medical reason not to be vaccinated.” Another 28 percent said there should be no state law on childhood vaccinations, 21 percent support limited exemptions for medical or religious reasons (the current Iowa law), 14 percent supported broader exemptions “for personal as well as medical or religious reasons,” and 3 percent were unsure. (The poll’s margin of error is plus or minus 3.4 percentage points.)

When Selzer polled Iowans on childhood vaccine requirements in early 2015, 59 percent of respondents favored “allowing only medical exemptions to childhood vaccinations,” 17 percent supported medical or religious exemptions, 16 percent said there should be no mandatory childhood vaccines, 6 percent supported broader personal exemptions, and 2 percent were unsure.

Communications researchers have long found that what’s in the news can influence how people view certain issues. So it’s notable that Selzer’s 2015 poll was in the field soon after a national measles outbreak, whereas the new survey took place after months of intense political controversy over coronavirus vaccination requirements.

Even though the new survey asked Iowans about laws on vaccinations “other than for COVID-19,” a partisan divide was apparent. Leys reported,

Just 17% of Iowa Republicans favor requiring all children to be vaccinated against diseases other than COVID-19 unless they have a doctor-signed statement saying they have a medical reason not to receive the shots. But 56% of Iowa Democrats favor such a strict requirement, as do 34% of political independents.

On the other hand, 46% of Iowa Republicans say the state should have no law on childhood vaccinations, compared to just 5% of Democrats and 27% of political independents.

The poll also finds gender differences in how people feel about mandatory vaccinations for kids. Just 20% of Iowa women think there should be no law requiring such shots, compared to 35% of men.

Differences of opinion between men and women often mirror partisan splits, with women more likely to align with views generally held by Democrats.

In contrast, Leys noted in his write-up of the 2015 Iowa Poll, “Majority support for the tighter requirement spans political party affiliation and gender.” That article quoted several respondents (including a Republican) who saw vaccine requirements as helping to save lives.

Leys’ current article quotes a Republican respondent who denied that vaccines helped eradicate once prevalent diseases. Echoing conservative misinformation about “natural immunity” offering superior protection against COVID-19, this man “said he believes diseases such as polio have waned mainly because people’s bodies built up their own immunity.”

Influential figures and media outlets that pushed falsehoods about COVID-19 have contributed to many preventable deaths of Americans who chose not to get vaccinated as a result. The new poll raises concerns that more Iowa parents will choose not to immunize their children against other diseases. Among respondents with children under age 18, 31 percent said the state should have no law requiring vaccines, while just 27 percent said children should be vaccinated unless a doctor confirms a medical reason not to get the shot.

If recent trends in public opinion continue, GOP lawmakers may eventually push for eliminating all mandatory childhood vaccinations. (A bill under consideration this year would ban only COVID-19 vaccine requirements for schools or child care centers.)

Public health experts, especially those with conservative bona fides, should speak out about the value of herd immunity and how Iowa’s current vaccine laws have successfully prevented outbreaks of dangerous diseases. And ambitious Republicans like Reynolds should stop valorizing those who refuse safe, effective vaccines as principled defenders of freedom.

UPDATE: A reader speculated that “the culture war divisions started with the HPV vaccines more than a decade ago and COVID simply made it explode. Mostly due to the convergence of Trump and social media.” That’s an interesting hypothesis. But I think misinformation about the HPV vaccine predated the 2015 Iowa Poll that found no significant partisan divisions on childhood vaccinations.