Results of Round 2 of Delhi’s sero survey likely by mid-august

NEW DELHI: More than a hundred teams of the three-four members will fan out across the Capital in the first five days of August to collect blood from around 20,000 people, health officials in Delhi said on Tuesday, giving new details on an upcoming survey that could help determine how much closer Delhi is to achieving herd immunity to Sars-cov2, the virus that causes Covid-19. The results of the second such serological study in the city are expected by midaugust. The blood will be used to check for antibodies that indicate a person was once infected and has since recovered and now possibly immune. If more than 40-65% of the population has such antibodies, Delhi will have, possibly, reached the herd immunity threshold. This is when an infectious diseases peters out as vulnerable people dwindle.

The first citywide survey of this sort, covering close to 21,800 people between June 27 and July 10, showed 22.86% of those tested had the antibodies.

Like that exercise, the one next month will draw on samples that are representative of the city’s population. “For the second round of the survey, the number of samples to be collected from each ward and each district will be decided by the researchers from Maulana Azad Medical College,” said a district official.