US President Donald Trump signed an executive order Monday pushing for a rethink of school vaccine mandates and repeating calls for the measles, mumps and rubella (MMR) vaccine to be separated into three individual shots. Curbing vaccines has been a key priority for Health Secretary Robert F. Kennedy Jr, who founded an anti-vaccine non-profit and has long promoted a disproven link between immunisation and autism. The federal government does not have direct control over several areas covered by the order. States, for example, have the authority to require vaccinations for students to attend school. On these points Trump's move is more of a suggestion than an order. "States and territories are advised to review" the Trump administration's recommendations on "immunisation requirements for contexts such as school enrolment and attendance," the order states. In another section, it says the US Health and Human Services department will form a task force to offer the MMR shot as individual vaccines "by working with the private sector and other countries as appropriate, while guaranteeing continued availability of combination vaccines and those vaccines recommended for shared clinical decision-making."