Paul L Delamater1, S Cassandra Pingali2, Alison M Buttenheim3, Daniel A Salmon4, Nicola P Klein5, Saad B Omer6. 1. Department of Geography and Carolina Population Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina; Departments of pld@email.unc.edu. 2. Epidemiology and. 3. Department of Family and Community Health, School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania. 4. Department of International Health, Johns Hopkins University, Baltimore, Maryland; and. 5. Kaiser Permanente Vaccine Study Center, Oakland, California. 6. Global Health, Emory University, Atlanta, Georgia.
Abstract
BACKGROUND AND OBJECTIVES: California implemented Senate Bill 277 (SB277) in 2016, becoming the first state in nearly 30 years to eliminate nonmedical exemptions from immunization requirements for schoolchildren. Our objectives were to determine (1) the impacts of SB277 on the percentage of kindergarteners entering school not up-to-date on vaccinations and (2) if geographic patterns of vaccine refusal persisted after the implementation of the new law. METHODS: At the state level, we analyzed the magnitude and composition of the population of kindergarteners not up-to-date on vaccinations before and after the implementation of SB277. We assessed correlations between previous geographic patterns of nonmedical exemptions and patterns of the remaining entry mechanisms for kindergarteners not up-to-date after the law's implementation. RESULTS: In the first year after SB277 was implemented, the percentage of kindergartners entering school not up-to-date on vaccinations decreased from 7.15% to 4.42%. The conditional entrance rate fell from 4.43% to 1.91%, accounting for much of this decrease. Other entry mechanisms for students not up-to-date, including medical exemptions and exemptions for independent study or homeschooled students, largely replaced the decrease in the personal belief exemption rate from 2.37% to 0.56%. In the second year, the percentage of kindergartners not up-to-date increased by 0.45%, despite additional reductions in conditional entrants and personal belief exemptions. The correlational analysis revealed that previous geographic patterns of vaccine refusal persisted after the law's implementation. CONCLUSIONS: Although the percentage of incoming kindergarteners up-to-date on vaccinations in California increased after the implementation of SB277, we found evidence for a replacement effect.
BACKGROUND AND OBJECTIVES: California implemented Senate Bill 277 (SB277) in 2016, becoming the first state in nearly 30 years to eliminate nonmedical exemptions from immunization requirements for schoolchildren. Our objectives were to determine (1) the impacts of SB277 on the percentage of kindergarteners entering school not up-to-date on vaccinations and (2) if geographic patterns of vaccine refusal persisted after the implementation of the new law. METHODS: At the state level, we analyzed the magnitude and composition of the population of kindergarteners not up-to-date on vaccinations before and after the implementation of SB277. We assessed correlations between previous geographic patterns of nonmedical exemptions and patterns of the remaining entry mechanisms for kindergarteners not up-to-date after the law's implementation. RESULTS: In the first year after SB277 was implemented, the percentage of kindergartners entering school not up-to-date on vaccinations decreased from 7.15% to 4.42%. The conditional entrance rate fell from 4.43% to 1.91%, accounting for much of this decrease. Other entry mechanisms for students not up-to-date, including medical exemptions and exemptions for independent study or homeschooled students, largely replaced the decrease in the personal belief exemption rate from 2.37% to 0.56%. In the second year, the percentage of kindergartners not up-to-date increased by 0.45%, despite additional reductions in conditional entrants and personal belief exemptions. The correlational analysis revealed that previous geographic patterns of vaccine refusal persisted after the law's implementation. CONCLUSIONS: Although the percentage of incoming kindergarteners up-to-date on vaccinations in California increased after the implementation of SB277, we found evidence for a replacement effect.
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Authors: Saad B Omer; Kristen Allen; D H Chang; L Beryl Guterman; Robert A Bednarczyk; Alex Jordan; Alison Buttenheim; Malia Jones; Claire Hannan; M Patricia deHart; Daniel A Salmon Journal: Pediatrics Date: 2018-01 Impact factor: 7.124
Authors: Jennifer L Richards; Bradley H Wagenaar; Joshua Van Otterloo; Rahul Gondalia; Jessica E Atwell; David G Kleinbaum; Daniel A Salmon; Saad B Omer Journal: Vaccine Date: 2013-05-10 Impact factor: 3.641
Authors: Salini Mohanty; Caroline M Joyce; Paul L Delamater; Nicola P Klein; Daniel Salmon; Saad B Omer; Alison M Buttenheim Journal: Vaccine Date: 2020-01-22 Impact factor: 3.641
Authors: Paul L Delamater; Alison M Buttenheim; Nicola P Klein; Salini Mohanty; Daniel A Salmon; Saad B Omer Journal: Ann Intern Med Date: 2019-11-05 Impact factor: 25.391
Authors: Taylor A Holroyd; Amanda C Howa; Paul L Delamater; Nicola P Klein; Alison M Buttenheim; Rupali J Limaye; Tina M Proveaux; Saad B Omer; Daniel A Salmon Journal: Hum Vaccin Immunother Date: 2020-11-24 Impact factor: 3.452
Authors: Taylor A Holroyd; Amanda C Howa; Tina M Proveaux; Paul L Delamater; Nicola P Klein; Alison M Buttenheim; Rupali J Limaye; Saad B Omer; Daniel A Salmon Journal: Hum Vaccin Immunother Date: 2021-01-25 Impact factor: 3.452