State of the UK epidemic
To better understand the state of the epidemic in the UK, we recommend focusing on indicators for the 4 nations of the UK individually, rather than an average value across the UK.
Estimates of the R value and growth rate for England and NHS regions are given below.
The latest ranges for R values and growth rates in the devolved administrations are published on their respective websites:
UK estimates of R and growth rate are averages over different epidemiological situations and should be regarded as a guide to the general trend rather than a description of the epidemic state.
Given the increasingly localised approach to managing the epidemic, particularly between nations, UK-level estimates are less meaningful than previously and may not accurately reflect the current picture of the epidemic.
The R value and growth rates for the 4 nations and NHS England regions are more robust and useful metrics than those for the whole UK. As a result, UK estimates of the R value and growth rate will no longer be produced.
Latest R and growth rate for England
An R value between 0.8 and 1.0 means that, on average, every 10 people infected will infect between 8 and 10 other people.
A growth rate of between -5% and -1% means that the number of new infections is shrinking by between 1% and 5% every day.
These estimates represent the transmission of COVID-19 2 to 3 weeks ago, due to the time delay between someone being infected, developing symptoms, and needing healthcare.
Latest by NHS England regions
These are the latest R and growth rate estimates by NHS England regions.
|Region||R||Growth rate % per day|
|England||0.8 to 1.0||-5 to -1|
|East of England*||0.8 to 1.1||-5 to 1|
|London*||0.8 to 1.1||-5 to 1|
|Midlands*||0.7 to 0.9||-7 to -3|
|North East and Yorkshire||0.7 to 1.0||-6 to -1|
|North West*||0.7 to 0.9||-7 to -2|
|South East*||0.7 to 0.9||-6 to -2|
|South West*||0.7 to 1.1||-6 to 0|
* Particular care should be taken when interpreting these estimates, as they are based on low numbers of cases or deaths and/or dominated by clustered outbreaks. They should not be treated as robust enough to inform policy decisions alone.
When the numbers of cases or deaths are at low levels and/or there is a high degree of variability in transmission across a region, then care should be taken when interpreting estimates of R and the growth rate. For example, a significant amount of variability across a region due to a local outbreak may mean that a single average value does not accurately reflect the way infections are changing throughout that region.
Estimates for R and growth rates are shown as a range, and the true values are likely to lie within this range. The estimate intervals for R and growth rate may not exactly correspond to each other due to the submission of different independent estimates and rounding in presentation.
See afrom 29 May 2020 for:
- the 7 NHS England regions
Historical UK estimates up to 26 March 2021 are also included. The time series document is updated regularly.
Other key statistics
The ONS Infection Survey provides information on:
- the number of new infections of the disease identified during a specified time period (incidence)
- the proportion of the population that test positive for the disease in the community at any given point in time (positivity rate or prevalence)
Other data on testing, cases, healthcare, vaccinations and deaths is available at the Coronavirus (COVID-19) in the UK dashboard.
About R and growth rate
The reproduction number (R) is the average number of secondary infections produced by a single infected person.
An R value of 1 means that on average every person who is infected will infect 1 other person, meaning the total number of 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. The higher R is above 1, the more people 1 infected person infects and so the faster the epidemic grows.
R can change over time. For example, it falls when there is a reduction in the number of contacts between people, which reduces transmission. R increases when the numbers of contacts between people rise, leading to a rise in viral transmission.
The growth rate reflects how quickly the numbers of infections are changing day by day. It is an approximation of the percentage change in the number of infections each day. If the growth rate is greater than 0 (+ positive), then the epidemic is growing. If the growth rate is less than 0 (- negative) then the epidemic is shrinking.
The size of the growth rate indicates the speed of change. A growth rate of +5% indicates the epidemic is growing faster than a growth rate of +1%. Likewise, a growth rate of -4% indicates the epidemic is shrinking faster than a growth rate of -1%. Further technical information on growth rate can be found on Plus magazine.
How growth rates are different to R estimates
R alone does not tell us how quickly an epidemic is changing. Different diseases with the same R can generate epidemics that grow at very different speeds. For instance, 2 diseases, both with R=2, could have very different lengths of time for 1 infected individual to infect 2 other people; one dise