COVID means COrona VIrus Disease
This disease is caused by the virus known as "SARS- CoV-2"- which is "severe acute respiratory syndrome coronavirus 2".
There have been many types of SARS Viruses- the ones that caused SARS a few years ago, MERS that caused the respiratory disease in the Middle Eastern countries and a few more.
Even though in the initial stages the virulence was extremely high causing a high number of deaths, the severity seems to have lessened possibly due to the vaccination and also possibly due to less severe virulence of the virus.
Dr.Thampy has conducted a research topic in the COVID infected patients at his hospital and has gotten it published in a Journal.