美国总统特朗普于2026年8月11日签署行政令，要求联邦政府支持11种核心儿童疫苗，并推动对疫苗接种方案的全面改革[1]。该行政令呼吁将联合疫苗如麻疹、腮腺炎、风疹疫苗（MMR）分离为三种单病种疫苗，并在不同就诊时间分散施打[1]。
医学界对这一政策普遍持反对态度。共和党参议员比尔·卡西迪（医学博士）谴责该命令，指出"总统没有专业知识做出这些改变"[1]。美国儿科学会主席安德鲁·瑞辛估计，在美国开发和批准分离疫苗可能需要十多年[1]。梅克制药公司表示，没有已发布的科学证据显示分离MMR疫苗有任何益处[1]。公共卫生专家指出，间隔施打疫苗会增加儿童在易感期的风险，且目前美国无相关单独疫苗许可证[1]。此外，数十年的科学研究已确认疫苗与自闭症之间不存在关联[1]。
改革计划出台之际，美国正经历35年来最严重的麻疹疫情爆发[1]。卫生部长小罗伯特·肯尼迪曾在1月份寻求从17种疾病疫苗中移除6种[1]。
President Trump signed an executive order on August 11, 2026, directing a comprehensive reform of American childhood immunization practices [1]. The order mandates federal support for eleven core childhood vaccines while calling for the separation of combination vaccines, particularly the MMR vaccine, into three individual disease-specific shots to be administered at different appointment times [1].
The policy shift has drawn sharp criticism from medical professionals. Republican Senator Bill Cassidy, a physician, denounced the order, stating that "the president does not have the expertise to make these changes" [1]. The American Academy of Pediatrics' president Andrew Reisin cautioned that developing and obtaining approval for separated vaccines in the United States could require more than a decade [1]. Merck Pharmaceuticals noted there is no published scientific evidence demonstrating any benefit to separating the MMR vaccine [1]. Public health experts warn that spacing out vaccinations increases children's window of vulnerability to disease during their most susceptible years [1].
The initiative echoes earlier efforts by Health and Human Services Secretary Robert F. Kennedy Jr., who sought in January to remove six diseases from federal childhood vaccine recommendations out of seventeen [1]. The timing of the order is significant, as the United States is currently experiencing its worst measles outbreak in thirty-five years [1]. Decades of scientific research and broad scientific consensus have found no link between vaccines and autism [1].