PUNE: Some 6,000 “high-risk” individuals, including frontline healthcare workers and close contacts of infected patients, will undergo tests to determine if a recombinant Bacille Calmette-Guerian (BCG) vaccine can boost human immunity against Covid-19.This is set to be the largest human trials yet in the country against the new coronavirus.The trials, approved by the Drug Controller General of India (DCGI), is set to start within a week at 40 hospitals. Pune’s Bharati hospital, KEM hospital and Symbiosis hospital are among the selected facilities, said Adar Poonawalla, owner and CEO of the Serum Institute of India (SII), which is starting the tests.The BCG vaccine, first administered to humans in 1921, is a known treatment for tuberculosis (TB), a highly infectious disease caused by a bacterium that affects the lungs. First developed by French researchers Albert Calmette and Camille Guerin, the BCG vaccine has become one of the most widely used vaccines in the world and is mandatory across Africa, Asia and South America. According to estimates, some 100 million newborns are given a shot every year.It is also part of the Indian government’s childhood immunization programme.Studies have also shown that the BCG vaccine has the ability to improve the body’s immune response and protection against other infections. Besides TB, the vaccine has also worked against leprosy."The aim now is to see if our recombinant BCG vaccine (VPM1002) can reduce infection, incidence and disease severity among high-risk individuals," Poonawalla said. "A similar trial has also been approved by the Paul Ehrlich Institute (PEI), the German regulatory authority. In addition to Germany, we will also be starting clinical trials in Australia, New Zealand, United States and Canada, very shortly."The trial design is adaptive, which means the vaccine can be fast-tracked for commercial use even when a sizeable number of the enrolled persons show promising results."This unique adaptive design will enable us to speedily bring the vaccine for use. This means, if we see efficacy early enough during the course of the trial, we will be able to approach the DCGI for marketing authorization and vaccination of our frontline health workers," the SII's additional medical director, Hitt Sharma, said. Sharma added that the DCGI has a specific committee that will oversee the study to ensure it is safe and appropriate for the group of subjects being studied.SII’s director of research and development Umesh Shaligram said: "We are trying to find out if the vaccine prevents Covid-19 infection among high-risk individuals and reduces its severity. This crucial information collected during the study may enable us to offer this vaccination to other people in future."It has become extremely important for India to shield its healthcare workers against Covid-19. For example, over 100 medical staff have contracted the disease in Mumbai."There is an urgent need to ensure the safety of our healthcare workers, who are at the forefront fighting the epidemic," said Pune-based surgeon Ashwin Porwal. "A recombinant BCG vaccine can be a good choice once its safety and efficacy have proven through clinical trials. We are pinning our hopes on its effectiveness against Covid-19."