https://www.nature.com/articles/d41586-021-01059-y
kvThe pandemic is sweeping through India at a pace that has staggered scientists. Daily case numbers have exploded since early March: the government reported 273,810 new infections nationally on 18 April. High numbers in India have also helped drive global cases to a daily high of 854,855 in the past week, almost breaking a record set in January.
Just months earlier, antibody data had suggested that many people in cities such as Delhi and Chennai had already been infected, leading some researchers to conclude that the worst of the pandemic was over in the country.