What does it mean that polio was found in wastewater in London and New York? What is “vaccine-derived” polio? What does eradication mean, and how will we achieve it? On this World Polio Day, Dr. Ananda Bandyopadhyay, deputy director of the polio team at the Bill & Melinda Gates Foundation, explains the most up-to-date information and maps out the future of tackling polio. Read The Lancet's recent editorial on polio eradication: Polio eradication: falling at the final hurdle? Read the recent article on detecting polio in London: Sustained detection of type 2 poliovirus in London sewage between February and July, 2022, by enhanced environmental surveillance You can continue the conversation with Jessamy and Gavin on Twitter by following them at @JessamyBagenal and @GavinCleaver.