What is the ‘R’ number and how will it determine when societies can escape lockdown?

What is the ‘R’ number and how will it determine when societies can escape lockdown? The reproduction — or ‘R’ — number is a measure used by epidemiologists to determine how rapidly a disease spreads through a population. It’s calculated using the average number of new cases generated by an infected person. If the number is below 1, it indicates the virus is contracting while numbers exceeding 1 indicate exponential growth. Politicians are keeping a close eye on the R number and countries who have managed to push the figure below this crucial threshold have slowly begun lifting lockdowns. Wired has the full breakdown on how health experts are using R to track the virus.