US policies are making a resurgence of vaccine-preventable diseases inevitable

AI Summary

US health secretary Robert F Kennedy Jr acknowledged the high effectiveness of the MMR vaccine amid a resurgence of measles in the US. However, a recent executive order mandating separate doses for MMR vaccination lacks scientific support and risks lowering vaccine coverage, potentially worsening the public health threat.

After being prompted in an interview on 2 August, US health secretary Robert F Kennedy Jr said that parents should vaccinate their children against measles and acknowledged that two doses of the measles, mumps, and rubella (MMR) vaccine are about 97% effective.1 Just days later, he accompanied US president Donald Trump as he signed an executive order that will require the MMR vaccine to be delivered in separate doses.2 This order has no scientific basis, will increase pressure on health providers, and by inconveniencing families and sowing doubt and confusion, will also certainly reduce vaccine coverage. Public confidence in vaccines cannot be turned on only when an outbreak becomes impossible to ignore, as it has with measles in the US.The US is experiencing a resurgence of measles after it was eliminated over 25 years ago. As of 6 August 2026, 2465 confirmed measles cases had been reported in the US...