If the vaccination drive against coronavirus is not ramped up and COVID-19-appropriate behaviour is not maintained, there is a possibility of a third wave of the pandemic in six to eight months, a panel of scientists has said. They are involved in the Sutra Model which uses mathematics to project the trajectory of COVID-19. We spoke with Dr M Vidyasagar of IIT-HYDERABAD on the projections. He said India's second wave of Covid is expected to decline by June end to 15 to 20 thousand cases a day.