The massive 30 per cent jump in Covid-19 cases in 24 hours on April 13 to over 10,000 cases from 7,800-odd the day before, the highest in 223 days, is a potent reminder of the deeply infectious nature of this virus that has afflicted the world since the end of 2019. As on April 13, the health ministry has recorded 44,998 active cases. As before, Kerala, Maharashtra, Delhi, and Uttar Pradesh have recorded the heaviest case-loads, suggesting a heavy incidence of reinfection. Though the medical fraternity has underlined the mild nature of the current XBB.1.16 variant, also known as Arcturus,