R number in Wales lower than in England

THE latest estimate of the R number for coronavirus in Wales is now significantly lower than in England, writes Will Hayward.

The R number is the amount of people each person with Covid-19 is infecting with the virus.

If that number goes above one, the number of people becoming infected with the virus will grow exponentially – but as long as it remains below one, the number of people infected with the virus will continue to fall.

In Wales, the most recent estimate of the reproduction number from the UK Government’s pandemic modelling body SPI(M) is between 0.5 and 0.9.

Due to the low number of cases, the estimate of R is now shown as a range without a central estimate on the Welsh Government website.

There is greater uncertainty in the estimates for Scotland, Wales, and Northern Ireland, partly due to the smaller numbers of cases and deaths compared to England. This is why the range for Wales is so big.

The same is true for Scotland, where the current range is between 0.9 and 1.4.

For England, the R number is 0.9 to 1.1.

The Department of Health in England publishes the R number for every region once a week. The R number in Wales is likely lower than every region in England.

East of England – 0.8-1; London – 0.8-1.1; Midlands – 0.8-1; North-East and Yorkshire – 0.8-1; North-West – 0.8-1; South-East – 0.8-1; South-West – 0.8-1.1.

Wales has a lower R rate than every part of the UK except Northern Ireland, which is similar at between 0.5 and 0.9.

At the start of the crisis the R rate was as high as two and there were lots of cases. This made the R rate a very useful measurement.

However, as there are fewer cases the R value becomes less useful because with a small sample size even one or two new cases can skew the number.

The Welsh Government is therefore not using the R rate as much now and instead has a list of indicators it is looking at to decide if Wales needs to go back into lockdown.

These indicators are designed to spot spikes before Wales needs to go back into a full lockdown.

Welsh Government health experts will use various types of data to make a decision. These are divided into circuit-breakers and early warning indicators.

Early warning indicators let Government know a spike could be on the way. Circuit-breakers are points where an immediate lockdown would be ordered.