Later this month, India will be removed from a dwindling list of countries where polio is considered endemic, a huge achievement made possible by people like Madara, a 76-year-old street hawker.
At a temporary immunisation camp in a slum in the northern district of Ghaziabad, 23 kilometres (14 miles) from New Delhi, he is busy at work shepherding boisterous children into queues.
All around, social workers break open tiny bottles containing a polio vaccine, selecting children from the thronging crowd of toddlers and babies and squirting two drops into their mouths.