Vaccination deniers gaining 'traction' on social media, health chief warns

London (CNN)Anti-vaccination "fake news" being spread on social media is fueling a rise in measles cases and a decline in vaccination uptake, the head of England's National Health Service (NHS) has warned.

Simon Stevens said "vaccination deniers" are gaining traction through their use of social media platforms including Instagram, WhatsApp and YouTube.
"Across the world, two to three million lives are saved each year by vaccination," Stevens said at a health summit on Friday. "But as part of the fake news movement, actually the vaccination deniers are getting some traction.
"Last year, for example, we saw more than triple the number of measles cases across England than we had seen the year before despite the fact that clearly, vaccination works," he added.
    Anti-vaccination groups frequently use social media platforms to spread conspiracy theories or misinformation about vaccine use, despite the fact that such theories have been conclusively debunked by the medical community.
    Stevens said discussions within the health body have focused on how to stem the spread of anti-vaccination ideas on Instagram and YouTube, and referred to a parent at his daughter's primary school who had used WhatsApp to express concern about children's immune systems being "loaded up" with vaccines.
    This week, YouTube removed commercials from videos that promote anti-vaccination ideas.
    Stevens said that the vast majority of people who understand the benefits of v