Covid vaccination FAQs: How soon after the first shot will the immunity develop?

Around 20 lakh people have received their first jab of Covid vaccine in Tamil Nadu so far. Many of them are getting ready for the second dose. However, the time interval between two doses of Covishield has been extended from four-six weeks to four-eight weeks, while no such announcement has been made about Covaxin. This has left many confused.The New Indian Express spoke to infectious diseases experts including Dr Subramanian Swaminathan, Gleneagles Global Health City and Dr Vijayalakshmi Balakrishnan, Kauvery Hospital, to clear the air.