Immunity from prior Covid-19 infection may be reduced in presence of new variants, says researcher Gautam Menon

India recorded the highest single-day spike of Covid-19 cases at 1.07 lakh on Tuesday, according to the daily numbers announced by various states and union territories. The number of cases breached the 1-lakh mark for the second time in three days.

The Centre cautioned that the next four weeks were "very very critical" and sought people's participation to control the second wave of the Covid-19 pandemic. Maharashtra, Punjab and Chhattisgarh still remain the states of "maximum concern", the Health Ministry said.