{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T10:23:34Z","timestamp":1792664614640,"version":"4.5.0"},"reference-count":51,"publisher":"American Medical Association (AMA)","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA Pediatr"],"published-print":{"date-parts":[[2026,1,1]]},"abstract":"\n Importance<\/jats:title>\n Childhood vaccination rates have declined in many US states, contributing to outbreaks of vaccine-preventable diseases and raising concerns about policy effectiveness amid growing vaccine hesitancy.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n To evaluate the association between state repeal of nonmedical vaccine exemptions and kindergarten vaccination rates.<\/jats:p>\n <\/jats:sec>\n \n Design, Setting, and Participants<\/jats:title>\n This cross-sectional study used annual state-level kindergarten vaccination and exemption data from the Centers for Disease Control and Prevention for school years 2011 through 2023. A staggered difference-in-differences design compared states that repealed nonmedical exemptions with states that maintained such policies. The study included kindergarten students in US public and private schools across 37 to 43 states, depending on the outcome measure.<\/jats:p>\n <\/jats:sec>\n \n Exposures<\/jats:title>\n Total repeal of nonmedical vaccine exemptions in California (2015), New York (2019), Maine (2019), and Connecticut (2021). Partial repeal in Vermont (2015) and Washington (2019) was analyzed separately.<\/jats:p>\n <\/jats:sec>\n \n Main Outcomes and Measures<\/jats:title>\n State-level kindergarten vaccination rates for diphtheria-tetanus-acellular pertussis (DTaP), hepatitis B, measles-mumps-rubella (MMR), and poliovirus (polio) vaccines; rates of medical and nonmedical exemptions.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n Among 4 states with total repeal affecting approximately 2.8 million kindergarten students, repeal of nonmedical exemptions reduced overall exemption rates by 3.2 (95% CI, 1.9-4.4) percentage points within 3 years. Compared with nonrepeal states, vaccination rates rose by 4.1 (95% CI, 3.3-4.9) percentage points for DTaP, 2.8 (95% CI, 2.1-3.5) percentage points for hepatitis B, 4.0 (95% CI, 3.1-4.9) percentage points for MMR, and 3.8 (95% CI, 2.9-4.6) percentage points for polio. Minimal substitution toward medical exemptions occurred, an increase of only 0.4 (95% CI, 0.04-0.7) percentage points. Partial repeal of nonmedical exemptions demonstrated smaller, less persistent increases in vaccination rates.<\/jats:p>\n <\/jats:sec>\n \n Conclusions and Relevance<\/jats:title>\n State repeal of nonmedical vaccine exemptions was associated with increased kindergarten vaccination rates with minimal substitution toward medical exemptions. These findings suggest that nonmedical exemption repeal played a role in maintaining vaccination coverage in repeal states during a period of heightened vaccine hesitancy.<\/jats:p>\n <\/jats:sec>","DOI":"10.1001\/jamapediatrics.2025.4185","type":"journal-article","created":{"date-parts":[[2025,10,27]],"date-time":"2025-10-27T15:31:20Z","timestamp":1761579080000},"page":"56","source":"Crossref","is-referenced-by-count":10,"title":["State Repeal of Nonmedical Vaccine Exemptions and Kindergarten Vaccination Rates"],"prefix":"10.1001","volume":"180","author":[{"given":"Anthony","family":"Bald","sequence":"first","affiliation":[{"name":"Harvard Kennedy School, Cambridge, Massachusetts"},{"name":"Department of Economics, California State University, Fullerton, Fullerton"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samantha","family":"Gold","sequence":"additional","affiliation":[{"name":"Jeb E. Brooks School of Public Policy, Cornell University, Ithaca, New York"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Y. Tony","family":"Yang","sequence":"additional","affiliation":[{"name":"Department of Health Policy and Management, Milken Institute School of Public Health, The George Washington University, Washington, DC"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"10","reference":[{"issue":"32","key":"poi250058r2","doi-asserted-by":"publisher","first-page":"4574","DOI":"10.1016\/j.vaccine.2022.06.033","article-title":"Estimating the number of US children susceptible to measles resulting from COVID-19-related vaccination coverage declines.","volume":"40","author":"Gambrell","year":"2022","journal-title":"Vaccine"},{"issue":"2","key":"poi250058r3","doi-asserted-by":"publisher","first-page":"371","DOI":"10.2105\/AJPH.2013.301538","article-title":"A longitudinal analysis of the effect of nonmedical exemption law and vaccine uptake on vaccine-targeted disease rates.","volume":"104","author":"Yang","year":"2014","journal-title":"Am J Public Health"},{"issue":"5","key":"poi250058r4","doi-asserted-by":"publisher","first-page":"375","DOI":"10.1056\/NEJM200102013440511","article-title":"The last smallpox epidemic in Boston and the vaccination controversy, 1901-1903.","volume":"344","author":"Albert","year":"2001","journal-title":"N Engl J Med"},{"issue":"2","key":"poi250058r5","doi-asserted-by":"publisher","first-page":"175","DOI":"10.1080\/14760584.2019.1562344","article-title":"Current landscape of nonmedical vaccination exemptions in the United States: impact of policy changes.","volume":"18","author":"Bednarczyk","year":"2019","journal-title":"Expert Rev Vaccines"},{"issue":"5","key":"poi250058r6","doi-asserted-by":"publisher","first-page":"778","DOI":"10.2105\/AJPH.2004.046193","article-title":"Public health and the politics of school immunization requirements.","volume":"95","author":"Salmon","year":"2005","journal-title":"Am J Public Health"},{"issue":"8","key":"poi250058r7","doi-asserted-by":"publisher","first-page":"1383","DOI":"10.1377\/hlthaff.2014.1428","article-title":"Some state vaccination laws contribute to greater exemption rates and disease outbreaks in the United States.","volume":"34","author":"Bradford","year":"2015","journal-title":"Health Aff (Millwood)"},{"issue":"7","key":"poi250058r8","doi-asserted-by":"publisher","first-page":"1282","DOI":"10.1377\/hlthaff.2013.0239","article-title":"Exempting schoolchildren from immunizations: states with few barriers had highest rates of nonmedical exemptions.","volume":"32","author":"Blank","year":"2013","journal-title":"Health Aff (Millwood)"},{"key":"poi250058r9","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhealeco.2021.102480","article-title":"How important is the structure of school vaccine requirement opt-out provisions? Evidence from Washington, DC\u2019s HPV vaccine requirement.","volume":"78","author":"Churchill","year":"2021","journal-title":"J Health Econ"},{"issue":"14","key":"poi250058r10","doi-asserted-by":"publisher","first-page":"1757","DOI":"10.1001\/jama.296.14.1757","article-title":"Nonmedical exemptions to school immunization requirements: secular trends and association of state policies with pertussis incidence.","volume":"296","author":"Omer","year":"2006","journal-title":"JAMA"},{"issue":"41","key":"poi250058r11","doi-asserted-by":"publisher","first-page":"925","DOI":"10.15585\/mmwr.mm7341a3","article-title":"Coverage with selected vaccines and exemption rates among children in kindergarten\u2014United States, 2023\u201324 school year.","volume":"73","author":"Seither","year":"2024","journal-title":"MMWR Morb Mortal Wkly Rep"},{"issue":"1","key":"poi250058r12","doi-asserted-by":"publisher","first-page":"68","DOI":"10.1001\/jamapediatrics.2021.4251","article-title":"Association of the COVID-19 pandemic with routine childhood vaccination rates and proportion up to date with vaccinations across 8 US health systems in the Vaccine Safety Datalink.","volume":"176","author":"DeSilva","year":"2022","journal-title":"JAMA Pediatr"},{"issue":"8","key":"poi250058r13","doi-asserted-by":"publisher","first-page":"730","DOI":"10.1001\/jama.2025.8952","article-title":"Trends in county-level MMR vaccination coverage in children in the United States.","volume":"334","author":"Dong","year":"2025","journal-title":"JAMA"},{"key":"poi250058r19","doi-asserted-by":"publisher","first-page":"254","DOI":"10.1016\/j.jeconom.2021.03.014","article-title":"Difference-in-differences with variation in treatment timing.","volume":"225","author":"Goodman-Bacon","year":"2021","journal-title":"J Econom"},{"issue":"2","key":"poi250058r20","doi-asserted-by":"publisher","first-page":"200","DOI":"10.1016\/j.jeconom.2020.12.001","article-title":"Difference-in-differences with multiple time periods.","volume":"225","author":"Callaway","year":"2021","journal-title":"J Econom"},{"issue":"2","key":"poi250058r21","doi-asserted-by":"publisher","first-page":"175","DOI":"10.1016\/j.jeconom.2020.09.006","article-title":"Estimating dynamic treatment effects in event studies with heterogeneous treatment effects.","volume":"225","author":"Sun","year":"2021","journal-title":"J Econom"},{"issue":"6","key":"poi250058r22","doi-asserted-by":"publisher","first-page":"3253","DOI":"10.1093\/restud\/rdae007","article-title":"Revisiting event-study designs: robust and efficient estimation.","volume":"91","author":"Borusyak","year":"2024","journal-title":"Rev Econ Stud"},{"issue":"9","key":"poi250058r23","doi-asserted-by":"publisher","first-page":"2964","DOI":"10.1257\/aer.20181169","article-title":"Two-way fixed effects estimators with heterogeneous treatment effects.","volume":"110","author":"De Chaisemartin","year":"2020","journal-title":"Am Econ Rev"},{"key":"poi250058r24","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1162\/rest_a_01414","article-title":"Difference-in-differences estimators of intertemporal treatment effects.","author":"De Chaisemartin","year":"2024","journal-title":"Rev Econ Stat"},{"issue":"6","key":"poi250058r26","doi-asserted-by":"publisher","first-page":"619","DOI":"10.1001\/jamapediatrics.2015.4856","article-title":"California Senate Bill 277\u2019s grandfather clause and nonmedical vaccine exemptions in California, 2015\u20132022.","volume":"170","author":"Delamater","year":"2016","journal-title":"JAMA Pediatr"},{"issue":"9","key":"poi250058r27","doi-asserted-by":"publisher","first-page":"863","DOI":"10.1001\/jama.2017.9242","article-title":"Change in medical exemptions from immunization in California after elimination of personal belief exemptions.","volume":"318","author":"Delamater","year":"2017","journal-title":"JAMA"},{"issue":"5","key":"poi250058r28","doi-asserted-by":"publisher","first-page":"966","DOI":"10.1016\/j.jhealeco.2011.06.003","article-title":"Effectiveness of state-level vaccination mandates: evidence from the varicella vaccine.","volume":"30","author":"Abrevaya","year":"2011","journal-title":"J Health Econ"},{"key":"poi250058r29","doi-asserted-by":"publisher","DOI":"10.1016\/j.jhealeco.2021.102464","article-title":"Personal belief exemptions for school-entry vaccinations, vaccination rates, and academic achievement.","volume":"78","author":"Hair","year":"2021","journal-title":"J Health Econ"},{"issue":"1","key":"poi250058r31","doi-asserted-by":"publisher","first-page":"95","DOI":"10.1257\/pol.20170067","article-title":"Direct and spillover effects of middle school vaccination requirements.","volume":"11","author":"Carpenter","year":"2019","journal-title":"Am Econ J Econ Policy"},{"issue":"1","key":"poi250058r32","doi-asserted-by":"publisher","first-page":"49","DOI":"10.1001\/jama.2019.7924","article-title":"Associations of statewide legislative and administrative interventions with vaccination status among kindergartners in California.","volume":"322","author":"Pingali","year":"2019","journal-title":"JAMA"},{"issue":"2","key":"poi250058r33","doi-asserted-by":"publisher","DOI":"10.1001\/jamanetworkopen.2023.54710","article-title":"School vaccine coverage and medical exemption uptake after the New York State repeal of nonmedical vaccination exemptions.","volume":"7","author":"Correira","year":"2024","journal-title":"JAMA Netw Open"},{"issue":"6","key":"poi250058r34","doi-asserted-by":"publisher","DOI":"10.1542\/peds.2018-3301","article-title":"Elimination of nonmedical immunization exemptions in California and school-entry vaccine status.","volume":"143","author":"Delamater","year":"2019","journal-title":"Pediatrics"},{"issue":"16","key":"poi250058r35","doi-asserted-by":"publisher","first-page":"1585","DOI":"10.1001\/jama.2023.16995","article-title":"Kindergarten vaccination status in California after changes to medical exemption policy.","volume":"330","author":"Delamater","year":"2023","journal-title":"JAMA"},{"key":"poi250058r36","doi-asserted-by":"publisher","DOI":"10.1016\/j.labeco.2025.102715","article-title":"Promoting public health with blunt instruments: evidence from vaccine mandates.","volume":"96","author":"Abouk","year":"2025","journal-title":"Labour Econ"},{"issue":"10","key":"poi250058r37","doi-asserted-by":"publisher","first-page":"2053","DOI":"10.1111\/risa.14090","article-title":"The benefits and costs of U.S. employer COVID-19 vaccine mandates.","volume":"43","author":"Ferranna","year":"2023","journal-title":"Risk Anal"},{"issue":"2","key":"poi250058r39","doi-asserted-by":"publisher","first-page":"127","DOI":"10.1207\/s15324796abm3202_10","article-title":"An implementation intentions intervention to increase uptake of mammography.","volume":"32","author":"Rutter","year":"2006","journal-title":"Ann Behav Med"},{"issue":"43","key":"poi250058r40","doi-asserted-by":"publisher","first-page":"6235","DOI":"10.1016\/j.vaccine.2022.08.060","article-title":"Can financial incentives and other nudges increase COVID-19 vaccinations among the vaccine hesitant? A randomized trial.","volume":"40","author":"Jacobson","year":"2022","journal-title":"Vaccine"},{"issue":"1","key":"poi250058r41","doi-asserted-by":"publisher","first-page":"394","DOI":"10.1257\/pol.20210393","article-title":"Experimental evidence on the effectiveness of nonexperts for improving vaccine demand.","volume":"16","author":"Alsan","year":"2024","journal-title":"Am Econ J Econ Policy"},{"key":"poi250058r43","doi-asserted-by":"publisher","first-page":"653","DOI":"10.1257\/pandp.20231112","article-title":"The impact of large-scale social media advertising campaigns on COVID-19 vaccination: Evidence from two randomized controlled trials.","volume":"113","author":"Ho","year":"2023","journal-title":"AEA Pap Proc"},{"key":"poi250058r44","doi-asserted-by":"publisher","first-page":"45","DOI":"10.1016\/j.jhealeco.2017.01.002","article-title":"Effectiveness of vaccination recommendations versus mandates: evidence from the hepatitis A vaccine.","volume":"52","author":"Lawler","year":"2017","journal-title":"J Health Econ"},{"issue":"26","key":"poi250058r45","doi-asserted-by":"publisher","first-page":"10415","DOI":"10.1073\/pnas.1103170108","article-title":"Using implementation intentions prompts to enhance influenza vaccination rates.","volume":"108","author":"Milkman","year":"2011","journal-title":"Proc Natl Acad Sci U S A"},{"issue":"20","key":"poi250058r46","doi-asserted-by":"publisher","first-page":"2415","DOI":"10.1001\/jama.298.20.2415","article-title":"Asymmetric paternalism to improve health behaviors.","volume":"298","author":"Loewenstein","year":"2007","journal-title":"JAMA"},{"issue":"5","key":"poi250058r47","doi-asserted-by":"publisher","DOI":"10.1136\/bmjgh-2022-008684","article-title":"The unintended consequences of COVID-19 vaccine policy: why mandates, passports and restrictions may cause more harm than good.","volume":"7","author":"Bardosh","year":"2022","journal-title":"BMJ Glob Health"},{"issue":"2","key":"poi250058r48","doi-asserted-by":"publisher","DOI":"10.1080\/21645515.2023.2261176","article-title":"Exploring the impact of the New York State repeal of nonmedical vaccination exemptions on student enrollment, absenteeism, and school workload: perspectives from a survey of school administrators.","volume":"19","author":"Correira","year":"2023","journal-title":"Hum Vaccin Immunother"},{"issue":"2","key":"poi250058r49","doi-asserted-by":"publisher","DOI":"10.1001\/jamanetworkopen.2021.46467","article-title":"Evaluation of trends in homeschooling rates after elimination of nonmedical exemptions to childhood immunizations in California, 2012\u20132020.","volume":"5","author":"Patel","year":"2022","journal-title":"JAMA Netw Open"},{"issue":"19","key":"poi250058r51","doi-asserted-by":"publisher","first-page":"1981","DOI":"10.1056\/NEJMsa0806477","article-title":"Vaccine refusal, mandatory immunization, and the risks of vaccine-preventable diseases.","volume":"360","author":"Omer","year":"2009","journal-title":"N Engl J Med"},{"key":"poi250058r30","author":"Richwine","year":"2019"},{"key":"poi250058r38","author":"Gandhi","year":"2024"},{"key":"poi250058r42","author":"Campos-Mercade","year":"2024"},{"key":"poi250058r1","unstructured":"Centers for Disease Control and Prevention. Measles cases and outbreaks: measles (rubeola). Updated August 6, 2025. Accessed August 17, 2025. https:\/\/www.cdc.gov\/measles\/data-research\/index.html"},{"key":"poi250058r14","unstructured":"Jones? JM. Far fewer in U.S. regard childhood vaccinations as important. Gallup News. August 7, 2024. Accessed August 17, 2025. https:\/\/news.gallup.com\/poll\/648308\/far-fewer-regard-childhood-vaccinations-important.aspx"},{"key":"poi250058r15","unstructured":"Centers for Disease Control and Prevention. Vaccination coverage and exemptions among kindergartners. SchoolVaxView. Updated October 2, 2024. Accessed December 17, 2024. https:\/\/www.cdc.gov\/schoolvaxview\/index.html"},{"key":"poi250058r16","unstructured":"National Archives. Code of federal regulations: 45 CFR \u00a7 46.102. 2025. Accessed September 1, 2025. https:\/\/www.ecfr.gov\/current\/title-45\/subtitle-A\/subchapter-A\/part-46\/section-46.102"},{"key":"poi250058r17","unstructured":"National Conference of State Legislatures. State non-medical exemptions from school immunization requirements. Updated August 13, 2024. Accessed December 17, 2024. https:\/\/www.ncsl.org\/health\/state-non-medical-exemptions-from-school-immunization-requirements"},{"key":"poi250058r18","unstructured":"Baker? A, Callaway? B, Cunningham? S, Goodman-Bacon? A, Sant\u2019Anna? PHC. Difference-in-differences designs: a practitioner\u2019s guide.? arXiv. Preprint posted online March 17, 2025. Accessed March 20, 2025. doi:10.48550\/arXiv.2503.13323"},{"key":"poi250058r25","unstructured":"Freyaldenhoven? S, Hansen? C, P\u00e9rez P\u00e9rez? J, Shapiro? JM. Visualization, identification, and estimation in the linear panel event-study design. Working paper 29170. National Bureau of Economic Research. Accessed September 1, 2025. http:\/\/www.nber.org\/papers\/w29170"},{"key":"poi250058r50","doi-asserted-by":"crossref","unstructured":"Correira? JW, Morrison? KT, Doll? MK. Homeschooling trends before and after the New York state repeal of nonmedical vaccination exemptions.? medRxiv. Preprint posted online August 13, 2025. doi:10.1101\/2025.08.11.25333447?","DOI":"10.1101\/2025.08.11.25333447"}],"container-title":["JAMA Pediatrics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/jamanetwork.com\/journals\/jamapediatrics\/articlepdf\/2840422\/jamapediatrics_bald_2025_oi_250058_1766435170.07416.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,1,5]],"date-time":"2026-01-05T16:00:49Z","timestamp":1767628849000},"score":1,"resource":{"primary":{"URL":"https:\/\/jamanetwork.com\/journals\/jamapediatrics\/fullarticle\/2840422"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,1]]},"references-count":51,"journal-issue":{"issue":"1","published-print":{"date-parts":[[2026,1,1]]}},"URL":"https:\/\/doi.org\/10.1001\/jamapediatrics.2025.4185","relation":{},"ISSN":["2168-6203"],"issn-type":[{"value":"2168-6203","type":"print"}],"subject":[],"published":{"date-parts":[[2026,1,1]]}}}