Sabareesh Ramachandran

Abstract Three rounds of population-representative serological studies through India’s two COVID waves (round 1, 19 October-30 November 2020; round 2, 7-30 April 2021; and round 3, 28 June-7 July7, 2021) were conducted at the district-level in Tamil Nadu state (population 72 million). State-level seroprevalence in rounds 1, 2 and 3 were 31.5%, 22.9%, and 67.1%. Estimated seroprevalence implies that at least 22.6 and 48.1 million persons were infected by the 30 November 2020 and 7 July 2021.

Malani acknowledges funding from the Becker Friedman Institute at the University of Chicago to purchase a subscription to the Consumer Pyramids Household Survey and the support of the Barbara J. and B. Mark Fried Fund at the University of Chicago Law School. We thank Mahesh Vyas, Kaushik Krishnan, Chinmay Tumbe, Shamika Ravi, Rukmini S, Prabhat Jha, Arvind Subramanian, Justin Sandefur, Abhshek Anand, Anmol Somanchi and seminar participants at the CMIE weekly webinar for helpful comments.

[This is one of a series of posts we plan on the second wave in India. Previous posts have presented (1) an overview and discussion of the Amravati outbreak and (2) the behavioral change theory. Here we discuss the role that new variants could be playing in wave.