Latest R rate – SW’s has dropped

These are the latest R and growth rate estimates by NHS England regions. The values are shown as a range, the most likely true values are somewhere towards the middle of this range.

Region R Growth rate % per day
England 0.7-0.9 -4 to -1
East of England 0.7-0.9 -6 to -1
London 0.7-1.0 -5 to +1
Midlands 0.8-1.0 -4 to 0
North East and Yorkshire 0.7-0.9 -5 to -2
North West 0.7-1.0 -4 to 0
South East 0.7-0.9 -5 to -1
South West 0.6-0.9 -6 to 0

What is the R rate?

The reproduction number (R) is the average number of secondary infections produced by 1 infected person.

An R number of 1 means that on average every person who is infected will infect 1 other person, meaning the total number of new infections is stable. If R is 2, on average, each infected person infects 2 more people. If R is 0.5 then on average for each 2 infected people, there will be only 1 new infection. If R is greater than 1 the epidemic is growing, if R is less than 1 the epidemic is shrinking.

R can change over time. For example, it falls when there is a reduction in the number of contacts between people, which reduces transmission.


What is a growth rate?

The growth rate reflects how quickly the number of infections are changing day by day It is an approximation of the change of number infections each day. If the growth rate is greater than zero (+ positive), then the disease will grow. If the growth rate is less than zero (- negative) then the disease will shrink.

The size of the growth rate indicates the speed of change. A growth rate of +5% will grow faster than one with a growth rate of +1%. Likewise, a disease with a growth rate of -4% will be shrinking faster than a disease with growth rate of -1%.

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