The information about Sars-Cov-2 virus or Covid-19 is ever changing. With new variants of the virus cropping up across the globe, many questions remain unanswered. What is the new Delta variant? Is it more dangerous than earlier forms of the virus? Will old vaccines prove effective against the new emerging strains of the virus? In this episode of Covid Watch. Dr. Satyajit Rath sheds light on these issues.