To understand the spread of SARS-CoV2, in August and September 2020, the Council of Scientific and Industrial Research (India), conducted a sero-survey across its constituent laboratories and centers across India . Of 10,427 volunteers , 1058 (10.14 %) tested positive for SARS CoV2 anti-nucleocapsid (anti-NC) antibodies; 95% of which had surrogate neutralization activity . Three-fourth of these recalled no symptoms . Repeat serology tests at 3 (n=607) and 6 (n=175) months showed stable anti-NC antibodies but declining neutralization activity . Local sero-positivity was higher in densely populated cities and was inversely correlated with a 30 day change in regional test positivity rates (TPR). Regional seropositivity above 10% was associated with declining TPR . Personal factors associated with higher odds of sero-positivity were high-exposure work (Odds Ratio , 95% CI, p value; 2â23 , 1â92-2â59, <0.0001), use of public transport (1â79 , 1â43-2â24, <0.0001), not smoking (1â52 , 1â16-1â99 , 0â0257), non-vegetarian diet (1â67 , 1â41-1â99, <0.0001), and B blood group (1â36,1â15-1â61 , 0â001).