Oxford Professor Melinda Mills and Southampton’s Professor Will Jennings and their research team found unregulated social media sources pose a particular problem in contributing to vaccine hesitancy. The article warns that social media users can fall prey to an ‘echo chamber’ effect – where tailored recommendations, based on an individual’s ‘watch history’, underline an individual’s concerns and rarely provide alternative or expert views. Professor Mills said: ‘Misinformation proliferates on some social media platforms because users receive content suggestions aligned with their fears and watch histories, driving them into deeper rabbit holes. Complacency also emerged from a misunderstanding that ‘herd immunity’ had been reached and only the vulnerable need to be vaccinated. The video sharing platform, YouTube – which contains a high percentage of negative claims - was particularly linked to hesitancy.