Sir Patrick Vallance speaking at daily coronavirus press briefing

The video explains the R number, which indicates how many people one infected person will infect. An R number above 1 means the epidemic grows, while below 1 means it shrinks. The R number is calculated using various models, and in the UK, it is currently between 0.7 and 0.9, indicating a decrease in epidemic size. Calculating R at regional levels is challenging, so growth rates and incidence are also important metrics. These help in understanding the epidemic's status and managing outbreaks.

Why is it more challenging to determine the R number at regional and local levels?

What are the three important aspects to consider when analyzing the epidemic's status?