Over 62% Tamil Nadu population has Covid antibodies, says latest serosurvey

Among total samples, 17,624 individuals had IgG antibodies against SARS-CoV-2 cirus, according to the study, conducted by the Directorate of Public Health and Preventive Medicine in 888 clusters across the state.

In earlier state-wide surveys, the seropositivity was 31% in October-November last year, and 29% in the second phase of the survey held in April this year.

The latest survey, which was the third phase and conducted during the declining phase of the second wave of Covid-19 pandemic in Tamil Nadu, says, “intense vaccination drives across the state since January 16 and inclusion of 18+ age individuals for vaccination would have generated Protective Antibodies in the population.”

As on June 10, total number of people who were vaccinated — either single dose or both doses — in the state was 97.6 lakh.

According to the survey’s results, the crucial industrial belts in western Tamil Nadu such as Erode, Coimbatore and Tiruppur regions have reported around 45% seropositivity. This outcome was attributed to the consistent reporting of new Covid-19 cases in these regions.

Of 3,690 samples from 123 clusters in Chennai district surveyed, seropositivity was found at 82%. While Coimbatore reported 43%, two other major cities — Trichy and Madurai — reported 67% and 79%, respectively. Chengalpattu, Kancheepuram and Tiruvallur districts, which are either in the suburbs or are neighbouring regions of Chennai, reported 66%, 65% and 67% seropositivity, respectively.

Among other districts which reported above 70% seropositivity are Tenkasi (78%) and Theni (77%), southern districts bordering Kerala; Tirunelveli (76%), Ramanathapuram (75%), Dindigul (73%), Thoothukudi (72%), Kanyakumari (72%), Ranipet (70%), Cuddalore (70%) and Kallakurichi (70%).

On Saturday, Tamil Nadu reported 1,986 new Covid-19 cases. With 26 deaths reported due to the infection, the toll rose to 34,076. Over 2.15 crore people have taken vaccines against the virus through government-run and private hospitals in the state, as per data up to Friday.