Soon after US drug maker Moderna reported a successful Phase 1 trial of a Covid-19 vaccine, another vaccine developed in China reported positive results in early trials. Reporting their findings in the Lancet journal, researchers said patients who received a single dose of the vaccine produced certain immune cells within two weeks and immunizing anti-bodies within a 28-day inoculation period. The trial conducted across various labs tested 108 patients between the age of 18 to 60. The vaccine, classified as 'recombinant adenovirus type-5 vectored,' acts as a natural infection and works by teaching the immune system how to fight the virus. Phase 2 trial of the vaccine with 508 volunteers has already been started.