Just two months ago, on the 8th of March, India's health minister was quoted as saying that India was in the "endgame of the pandemic". But in the past few weeks, India's Covid caseload has risen sharply -- in fact, India accounted for 46% of the new Covid-19 cases recorded worldwide last week, and one in four of deaths globally. So, how did India get from relative calm to its new crisis? Melisa Idris and Sharaad Kuttan speak to Professor Sanjeev Krishna, Professor of Molecular Parasitology and Medicine, Institute of Infection and Immunity, London.