Professor Christina Pagel (UCL Mathematics) warns that the US Secretary of Health and Human Services’ efforts to undermine vaccines spreading around the world. Vaccines are one of the greatest public health success stories of all time. Over the past 50 years, they’ve saved an estimated 154 million lives . But in the US, both access to vaccines and public trust in them are being systematically undermined – not by conspiracy theorists online, but from within the highest levels of government. “ In