In February, Iowa’s House of Representatives advanced a bill that would bar schools from requiring any vaccines for student enrollment. If the bill passed, Iowa would become the only state not to mandate routine vaccinations for children entering public schools. Although the bill has stalled on the House floor, some of its proponents hope it will be a model for other states as legislation to weaken or eliminate mandates for all vaccines—not only those for COVID-19—pops up across the country. 

Anti-vaccine legislation is undergoing a transformation. Prior to the pandemic, anti-vaccine advocates sought legal loopholes to vaccination requirements through nonmedical exemptions, usually on religious or philosophical grounds. (Only six states do not recognize religious or “personal belief” exemptions to school vaccination requirements.) While nonmedical vaccine exemptions are promoted under the guise of personal or religious freedom, their biggest supporters are promoters of anti-vaccine misinformation. 

The anti-vaccine movement has spent years building the case for nonmedical exemptions nationwide. First Freedoms, a nonprofit run by Kevin Barry, lawyer and author of an anti-vaccine conspiracy book, gained attention in 2019 for challenging laws that restricted or eliminated the use of nonmedical vaccination exemptions for student enrollment. Anti-vaccine advocates have targeted religious and philosophical exemptions as a more attainable alternative to medical vaccine exemptions. 

The strategy has been successful. Between 2009 and 2017, the number of states allowing personal belief exemptions increased from 12 to 18. The national vaccine exemption rate for kindergarteners rose from 1.4 percent in 2011 to 2.5 percent in 2019, with some states reaching rates of nearly 8 percent. Of those children receiving vaccine exemption, only 0.3 percent were medical exemptions. Although exemption rates remained stable at 2.5 percent in the 2019-2020 school year, widespread school closures and delayed kindergarten entry brought on by the pandemic make the year an outlier in determining trends in vaccine exemptions. 

In COVID-19, vaccine opponents found the breakthrough they’d been waiting decades for after gaining mainstream traction in the 1980s and recruiting prominent public figures to the cause in the 1990s. Barry, who became a fixture of the legal opposition to COVID-19 vaccine mandates in New York and Connecticut, cites the use of fetal cell lines to develop the vaccines as a basis for religious exemptions. The cell lines used to develop COVID-19 vaccines were collected in the 1970s and ‘80s and have been used for decades to develop dozens of common drugs, including most over-the-counter pain, allergy, and cold medications, which are not opposed by anti-vaccine advocates. But Barry, who has been involved in the legal challenge to Connecticut’s removal of religious exemptions for school vaccinations and has assisted employees challenging vaccine mandates at large corporations, argues that the Supreme Court upholds religious rights even if they are not logical or consistent. He wrote in an email to PGN that “those using religious exemptions have genuine religious objections to vaccines.”

Having taken on COVID-19 vaccine mandates, anti-vaccine activists have their sights on championing legislation like Iowa’s anti-mandate bill that targets vaccines beyond COVID-19. UC Hastings law professor and vaccine legislation researcher Dorit Rubinstein Reiss notes that the anti-vaccine movement went from fringe to mainstream during the pandemic as it gained more support from politicians. “The movement hasn’t changed,” Reiss says, “but the object has.” 

The anti-vaccine movement went from fringe to mainstream during the pandemic as it gained more support from politicians. “The movement hasn’t changed,” Reiss says, “but the object has.” 

Just last month, Georgia joined Iowa in advancing a bill that eliminates all school vaccine requirements. Kansas advanced a bill to broaden nonmedical exemptions for student enrollment to allow anyone to claim that any vaccine goes against their religious beliefs without having to prove the sincerity of those beliefs. Louisiana is attempting to ban vaccination drives on school grounds or at school-related activities, while Oklahoma has advanced a bill that, if passed, would effectively criminalize school vaccine mandates. In all of these cases, legislation is being promoted by sponsors and supporters as pushing back against COVID-19 mandates, but the bills’ language is just vague enough for it to apply to all vaccines.

Long before the pandemic, vaccine researcher, pediatrician, and dean at Baylor College of Medicine Dr. Peter Hotez was an outspoken advocate of vaccines, warning of the dangers of the fringe anti-vaccine movement. Hotez authored a 2018 study that highlighted a rise in nonmedical vaccine exemptions and “hotspots” with high exemption rates. The danger posed by the anti-vaccine movement has grown as its rhetoric has gained mainstream traction. “My worry is the massive loss of life that the anti-vaccine movement has caused,” Hotez says. “They won’t stop at COVID-19. It will spread to varicella [chickenpox], HPV, and other vaccines.”

Legislation targeting broad vaccine mandates often coincides with declining public opinion on vaccines. In Iowa, nearly 28 percent of citizens believe no childhood vaccines should be required, and a further 14 percent support broad nonmedical exemptions. Similar trends can be seen nationwide—along decidedly partisan lines. A recent Economist/YouGov poll found that support for childhood vaccinations dropped significantly last year among Republicans, from 59 to 46 percent. Less than half of Republicans believe childhood vaccines to generally be “very safe,” compared to 72 percent of Democrats. 

Experts are not divided on the issue. The American Academy of Pediatrics, American Medical Association, American College of Physicians, and the American Nurses Association support the elimination of all nonmedical vaccine exemptions for schoolchildren for a simple reason: Exemptions to vaccine mandates lead to disease outbreaks. 

Where vaccine exemption laws are enacted, vaccine coverage drops and disease outbreaks become more common. One 2018 study of nonmedical exemptions found that a state’s nonmedical exemption rate is inversely related to its measles-mumps-rubella vaccination rates. In 2019, the Immunization Action Coalition released a report compiling evidence that several disease outbreaks can be directly linked to unvaccinated children in nonmedical exemption hotspots. 

Measles outbreaks in 2015 and 2019 pushed California and New York to end religious exemptions for vaccination. Maine became the fourth state to ban nonmedical exemptions for school children after a devastating whooping cough outbreak led to nearly 400 cases, almost six times the national incidence rate. Few states followed suit. In 2019, amid the worst measles outbreak in nearly three decades, states continued introducing vaccine exemption legislation that not only weakened the vaccine mandate but also threatened public health. 

In a span only of a decade, anti-vaccine advocates built a legal playbook to challenge vaccine mandates and seized on a global pandemic to erode public opinion about vaccines and expand their base of support.

Earlier this year, the U.N. warned that low vaccination rates in the Americas put the region at risk for a resurgence of polio, which was eradicated in the U.S. in 1979. The return of a disease that is largely seen as a relic of the past in the developed world may seem far-fetched, but Israel is currently fighting its first polio outbreak in over 30 years. Like the U.S., the country has a high national vaccination rate, but communities with low vaccination rates—often due to anti-vaccine religious beliefs—create hotspots for disease outbreaks. The U.S. faces a similar reality, with future outbreaks of diseases like measles, polio, and whooping cough all possible if vaccine mandates are not strengthened. 

In a span only of a decade, anti-vaccine advocates built a legal playbook to challenge vaccine mandates and seized on a global pandemic to erode public opinion about vaccines and expand their base of support. It’s unclear how the current crop of anti-vaccine mandate bills will stand up to the next stages of the legislative process. But the momentum that the movement has built over the last two years suggests that it has the potential to grow into a formidable political force.  “On their own, the anti-vax movement is fringe and not powerful,” Reiss concludes. “It’s the link to mainstream politicians that makes them concerning.”