The claim is mostly true because President Donald Trump did sign an order aimed at reducing recommended childhood vaccines on August 10, 2026, although the wording that he was merely set to sign it became outdated once the signing occurred.
Trump set to sign executive order aimed at reducing number of recommended childhood vaccines

Trump signs executive order calling for fewer childhood vaccines, falsely linking shots to autism
Source: cnbc.com
Key Evidence
CNN, CNBC, The New York Times, NBC News, U.S. News, The Independent, and News8000 all report that President Trump signed the order on August 10, 2026, rather than merely planning to sign it.
AOL's Reuters-based report says the order called for limiting the recommended schedule to 11 immunizations, while CNBC describes the measure as backing fewer routine vaccines.
The evidence supports the policy's stated aim, but the original wording is temporally outdated after the signing.
What the Evidence Shows
The search results consistently report that President Donald Trump signed an executive order on August 10, 2026, concerning the number and organization of recommended childhood vaccines. CNN, CNBC, The New York Times, NBC News, U.S. News, and other outlets describe the order as seeking fewer routine childhood vaccinations or a narrower set of core recommendations.
The claim's central substance is therefore supported: the order was aimed at reducing or revising the number of universally recommended childhood vaccines. Several results also report that the order identified 11 core vaccinations and encouraged reconsideration of the combined measles, mumps, and rubella vaccine, although the precise legal and practical effect of these recommendations is not fully established by the supplied summaries.
The timing is the main qualification. The phrase "set to sign" describes an expected future action, while most supplied sources state that the signing had already taken place on August 10, 2026. KTEN's result retains the prospective wording, but its title conflicts with the later or updated headlines from the other sources. The claim should therefore be understood as an earlier description of an anticipated action, not the most accurate description of the situation as of the stated current date.
The supplied results also report that Trump or the order linked vaccines to autism. CNBC characterizes that linkage as false, and the available scientific consensus does not support vaccines as a cause of autism. That issue is related context, but it is not necessary to establish whether the original timing and policy claim was accurate.