Picture used for representational purpose only
The public health department has been collecting at random blood (serum and plasma) samples from about 26,000 people in 888 clusters since March 27 for TN’s second serosurveillance for Covid-19. The survey would go on till the end of April as some districts began the survey after the polls.
Director of public health Dr T S Selvavinayagam said one of the objectives of the sero survey is to find if the community has developed herd immunity. Preliminary results could be expected a month after the survey ends. The sample population is also being asked to answer a questionnaire on occupation, exposure status, age, sex, travel history etc, which would give a more detailed account of the disease.