What happened
Analysis and impact
根据 Ars Technica 的报道，这项行政命令的核心内容包括削减对现有儿童疫苗接种项目的联邦支持，同时指示相关部门将资源导向“下一代疫苗平台”的开发。然而，这些被标榜为更安全、更有效的替代疫苗目前并不存在，其研发周期和可行性均属未知。特朗普在签署现场直接针对 MMR 疫苗发表言论，称其具有致命风险并与自闭症谱系障碍有关，这一论断与全球公共卫生领域的共识完全相悖。美国疾病控制与预防中心（CDC）及世界卫生组织（WHO）等权威机构均明确指出，MMR 疫苗是安全有效的，且与自闭症之间不存在任何因果关系。
将疫苗与自闭症关联的说法，源于 1998 年一篇后来被证实为欺诈并撤回的论文。此后二十余年间，全球范围内针对数百万儿童的大规模研究反复证实，疫苗不会增加自闭症风险。此次行政命令的签署，被公共卫生专家视为可能动摇美国数十年建立起来的疫苗信任和免疫屏障的举动。原文未提供该命令的具体实施时间表及受影响项目的详细清单，但其政策方向已引发医学界对麻疹、腮腺炎等可预防疾病卷土重来的深切担忧。
References
Original source text
President Trump signed an executive order Monday that makes sweeping, unilateral changes to federal vaccine recommendations. The order aims to reduce the number of lifesaving vaccines all children are recommended to get—from 18 to 11—while also splitting them up and spacing them out over more time and more medical visits.
The vaccine changes are not backed by evidence or spurred by new findings. Rather, they are based on false anti-vaccine fearmongering about harms, including the debunked claim that they cause autism, and misinformation that multiple vaccinations can "overwhelm" children's immune systems. This false claim has also been repeatedly debunked and explained.
During a signing event at the White House on Monday afternoon, Trump falsely claimed that pediatricians "have a vaccination that looks like the size of a bottle of soda," that is "poured into a little child's body, and bad things happen in too many cases. This is an explosion; this is an epidemic," Trump said.