Twitter loses legal protection in India from prosecution over users' posts after failure to comply with new IT rules. In a global first, UP police files FIR against Twitter and others for inciting communal trouble. A day Delhi High Court bail, student-activists Natasha Narwal, Devangana Kalita and Asif Iqbal Tanha remain in jail. Delhi Police files case in the Supreme Court, cites procedural delays in release. Covid Working Group chief Dr NK Arora has said that according to research in India, a single shot of Covishield had up to 61 per cent effectiveness against the Delta strain.