Chennai: Tamilnadu recorded an overall sero prevalence of 23 percent in the second State-wide cross-sectional sero survey conducted by the Health Department.

It means that 23 percent of the samples tested have antibodies against SARS CoV-2, the virus that causes the Covid-19 pandemic.

The survey shows the 23 per cent of the State’s population having antibodies against the coronavirus is notably an 8 per cent decline from the 31 per cent sero-prevalence shown in the 2020 October-November survey.

As per the department’s report, 22,904 people were tested across all districts except Chennai and 5,316 among them had antibodies. The highest sero-prevalence (49 per cent) is in Tiruvallur while the lowest (9 per cent) is in Nagapattinam. Chengalpattu, with 43 per cent, Kancheepuram, with 38 per cent, came second and third respectively.

The current hotspots — Coimbatore, Tiruppur and Erode — have shown an overall antibody prevalence of 20.5 per cent, 23 per cent and 17.2 per cent respectively in the second sero-survey.

This, the Directorate noted, indicated ‘low antibody prevalence’. It showed that neither natural antibody nor vaccine-induced antibody was widely prevalent in these hotspots.