The reproduction number, or R rate, of coronavirus transmission across the UK is between 1.2 and 1.3 according to the latest government figures.
The R measures the number of people, on average, that each sick person will infect. If R is greater than 1, the epidemic is generally seen to be growing. If R is less than 1 the epidemic is shrinking.
Here’s what the R is near you
East of England 1.0 – 1.3 (last week: 1.1 – 1.3)
London 0.9 – 1.2 (1.1 – 1.4)
Midlands 1.2 – 1.4 (1.1 – 1.4)
North East and Yorkshire 1.1 – 1.3 (1.1 – 1.4)
North West 1.2 – 1.5 (1.0 – 1.4)
South East 1.0 – 1.2 (1.1 – 1.4)
South West 1.2 – 1.5 (1.1 – 1.5)
In Scotland the latest figures estimate the R rate is between 0.9 and 1.3.
In Wales the R rate is estimated to be between 1.0 and 1.3.
And in Northern Ireland it is estimated to be above 1.
Boris Johnson will host a Downing Street press conference on Friday afternoon.
The prime minister has repeatedly warned England’s national lockdown rules could be tightened if they are not “properly observed”.
Ahead of the briefing, No.10 said that scientists at the government’s Porton Down research facility are investigating the new Brazilian variant of coronavirus.
Priti Patel, the home secretary, said on Thursday tougher rules would not be introduced “today or tomorrow”. But she did not rule out new measures being announced next week.
Keir Starmer, the Labour leader, has said the current measures in England are “not strong enough” and accused the prime minister of being “slow to act”.
Scotland has toughened its lockdown restrictions to include reducing click and collect services to only those deemed essential from Saturday.
The R number, explained
The R number – sometimes referred to as the R0 – is the “basic reproduction number”. It’s used to measure the transmission potential of a disease.
The R value represents the number of people that one infected person will, on average, pass the virus on to. It’s influenced by characteristics of the specific disease (in this case, Covid-19), such as how easily it passes from person to person. Human behaviour – i.e. how closely we follow social distancing measures – will also impact the R number.
When the R number is below one, this suggests the number of cases is shrinking. Anything above one suggests cases and subsequent infections are growing – and is a cause for concern, because cases snowball.
While it can help indicate if lockdown measures are working, the R number doesn’t offer the full picture; the R value can show if an epidemic is getting bigger or smaller, but not how large it is.
“R should always be considered alongside the number of people currently infected,” the government website explains. “If R equals 1 with 100,000 people currently infected, it is a very different situation to R equals 1 with 1,000 people currently infected.”
This article originally appeared on HuffPost UK and has been updated.