66.2% have antibodies, two-fold increase since October 2020, indicates latest Serosurvey by Tamil Nadu government

A Serosurvey conducted by the Directorate of Public Health and Preventive Medicine in Tamil Nadu has indicated that 66.2% of the Southern Indian state’s population has developed antibodies to Covid-19. The presence of antibodies in the bloodstream shows that a person has either been infected with COVID-19 and developed antibodies to fight the virus or that the effect of vaccination is reflecting. 

This survey (random blood tests) which was done in July 2021 covered 26,610 persons across urban and rural areas of Tamil Nadu. The latest survey results showcase a steep increase in antibodies in the state’s population, as the current 62% is up from the 31% seen in Oct/Nov2020 and the 29% seen in April 2020. 

According to the Health department, 17,624 individuals had IgG antibodies against the SARS-CoV-2 Virus, which causes COVID-19. It is mentioned that the highest seropositivity of 84%v was observed in Virudhunagar district and the lowest of 37% was in Erode district. 

The Tamil Nadu Health Department conducted this survey during the declining stage of the second wave of COVID-19 in Tamil Nadu and when the vaccination drive had covered nearly 1 crore persons(either single or double dose) by June. Notably, the western districts of the state such as Erode, Coimbatore and Tiruppur have reported 45% seropositivity, which is said to be related to the consistent reporting of new cases in the region.

Based on tests across 70 districts in 21 states, the 4th National Serosurvey by Indian Council of Medical Research(ICMR) also says that nearly 2/3rds of the general population has antibodies against COVID-19. However, the data also raises alarm over the fact that, nearly 40crore people across India are still vulnerable to COVID-19. It also added that states/districts without antibodies had the risk of further COVID waves. 

Owing to the rise in cases in recent days, the Tamil Nadu Government had empowered local administrations, civic bodies to impose restrictions in crowded areas. In line with this, nine crowded market areas in Chennai were ordered shut until August 9th. The Government also warned the people against complacency, thus reminding them the woes of a Lockdown, in case of a severe spike in cases. Effective August 5th, Tamil Nadu Government has made RT-PCR tests or Double-vaccination certificates mandatory for those entering the state from Kerala, which is reporting almost half of India’s COVID-19 case load. In the case of those who have received both shots, they are allowed to enter Tamil Nadu 14 days after having taken the second jab.

After a period of significant decline to nearly 1,500 cases every day, Tamil Nadu’s COVID-19 cases are almost at 2,000 daily cases, as per the State Government data.