“We need to have a record of the first-time cases and re-infection cases. As per survey results, we are likely to have more cases of reinfection, but with the lack of a system to have a registry, we are left to assume that all cases are new ones,” said senior virologist Dr Jacob John, adding, that public health officials need to work on a registry to maintain a record of fresh cases besides arresting the surge.

According to experts, more than 60% virus exposure among people is required to reduce transmission and risk of re-infection is likely to be low. “The risks of re-infection are low as the cyclical trend of viruses is at least more than three years. With the increased movement of people, those who were unexposed are getting infected now. The surge cannot be due to another wave or variant in just a year. The younger population is getting infected now,” said Dr K Kolandaisamy, former public health director.

Health Secretary J Radhakrishnan stated that the survey indicated COVID exposure in more than 40% people in Chennai but lack of adherence to safety standards are the main challenges and acceptance of the vaccine needs to be stressed upon.