The centre has flagged Uttar Pradesh as a state of concern over the 'R' value of Covid, which refers to the rate at which an infected person can transmit it to others. The 'R' value in India's most populous state is over 1 and cases are "likely increasing", the Centre has said. Uttar Pradesh is reporting low infections and clocking a high rate of vaccination as of now, but the government said it is cautious.