The R0 value indicates how contagious an infectious disease is and hence it is an important marker to study the progression of a disease. Using the R0 value, the transmission rate of a disease or its decline can be calculated.
Countries have been trying to find out the R0 value of COVID-19 as a metric to find out the transmission rate of the virus.
Preliminary studies estimated a global R0 value for COVID-19 to be between 2 and 3. This means each infected person has spread the virus to an average of 2 to 3 people. But some recent studies suggest COVID-19 has an even higher R0 value.