Despite overwhelming evidence for the safety and effectiveness of COVID-19 vaccines, vaccine hesitancy has intensified during the COVID-19 pandemic and fueled skepticism toward other life-saving vaccines for children, adults, and pets.
A new study led by Boston University School of Public Health (BUSPH) researchers has revealed another troubling trend: anti-vaccine sentiment that was once reserved for individual beliefs and public discourse has turned into actual legislation in the US that could undermine vaccine uptake and pose a threat to public health.
Published in the American Journal of Public Health, the study shows that proposed bills aimed at reducing access to vaccines, weakening vaccination requirements and increasing vaccine exemptions rose dramatically in state legislatures from 2021-2023, at times outnumbering bills seeking to strengthen vaccine access and mandates. At least 40 percent of bills introduced in each full legislative cycle since the start of the pandemic are related to vaccination.
Party polarization is clearly driving this legislation: Republican lawmakers sponsored 86 percent of anti-vaccine bills introduced during that period. Democratic lawmakers, meanwhile, introduced 54 percent of vaccine bills, which are bills that advocated for increased access or funding and promotion of vaccines in state legislatures.
“Our work shows that state legislators affiliated with the Republican party are responsible for the vast majority of anti-vaccination bills introduced in recent years,” says the study’s corresponding author Dr. Matt Motta, who co-authored the study with Dr. Timothy Callaghan, who are both associate professors of health law, policy and management at BUSPH. “While the majority of these bills do not actually pass, it is important to remember that we live in an increasingly connected and globalized world in which low vaccine coverage in one part of the country can sicken thousands of miles away. Weakening vaccine regulations in one state puts everyone’s health at risk, as the current measles outbreak shows.”
Additionally, a sizable percentage of antivaccination legislation—24 percent—during this period received enough state legislative support to become law. Several states are enacting laws that expand religious or personal belief exemptions for child care and school vaccinations, as well as measures that prohibit employers from mandating certain vaccinations in the workplace.
“These anti-vaccine bills signal not only the dissatisfaction that some have with vaccines, but also the more hostile policy environments toward vaccination,” says Dr. Callahan. As the U.S. approaches November’s midterm elections, “who society chooses to elect in 2026 could shape vaccine policymaking for years to come,” he says.
This analysis is the first to explore these partisan differences between vaccine-related bills proposed before and after the pandemic. For the study, Dr. Motta and Dr. Callaghan, along with a team of student and graduate researchers at BUSPH, systematically categorized partisan changes in 1,513 vaccine-related bills introduced in state legislatures between 2019-2023. The team used preliminary data on all proposed vaccine-related bills in state legislatures from 2019-2023 through the State Vaccine Policy Project (SVPP), a first-of-its-kind initiative created to understand and inform policies that address the politicization of public health. The SVPP is housed in the Policy and Health Laboratory directed by Drs. Mota and Dr. Callahan at BUSPH.
In 2021, a total of 1,154 vaccine-related bills were introduced in state legislatures, compared to just 386 proposed bills in the 2019 legislative session. Over the four-year period, nearly 82 percent of bills proposed by Democrats were pro-vaccine, compared to less than 10 percent that were vaccines. By comparison, more than 65 percent of bills proposed by Republicans were anti-vaccination, compared to 28 percent that were pro-vaccination.
The rise of anti-vaccination legislation can be attributed in part to electing GOP lawmakers who want to appease anti-vaccination Republican voters who identify themselves as defenders of medical freedom, individual autonomy and parental rights, rather than vaccine opponents. But health experts also stress that vaccine hesitancy is a result of widespread misinformation, evolving public health guidelines and widespread mistrust of science that has persisted in the U.S. during and after the pandemic.
“No one likes to be told what to do. But our government has the ability and the obligation to take steps that protect public health,” says Dr. Mota. “To the many people who base their opposition to vaccination on deeply held values, political views, religious beliefs and more, I would say: infectious disease has no sense of morality or religious faith. Taking action to protect yourself and others is one of the safest and most effective actions you can take to live your life the way you want to live it.
The team says its findings also underscore the importance of voter participation in local elections and the need for continued efforts to improve communication about vaccines to the general public.
We need to recognize that the reasons people lack trust in science are multifaceted and that there is no single solution that will work to restore trust. We must also recognize that the messengers matter as much, if not more, than the message. For public health, this also means recognizing that public health officials will not always be the right messengers to encourage vaccine uptake. Identifying the right messages and messengers will require significant investment in vaccine communication research, which is currently severely underfunded.”
Dr. Timothy Callaghan, Associate Professor of Health Law, Policy and Management at BUSPH
In future research, the researchers plan to expand the SVPP data set to analyze vaccine legislation over a longer period of time, as well as explore how public experiences with vaccination have shaped legislation and vice versa. They will also consider health policies related to other issues, including gender-affirming care, reproductive health and water fluoridation.
“We hope to provide researchers with a large, up-to-date database cataloging health policy legislative activity across states so we can study how changes in our social and political world affect health policy and how changes in health policy affect public health,” says Dr.
