NIESR Weekly Covid-19 Tracker: Reproduction Number (R) and Forecasts of New Cases: R value for England remains below 1

Publication date: 22 Apr 2021 | Publication type: NIESR Covid-19 Tracker | NIESR Author(s): Thamotheram, C | Report number: 10

Main points

  • We report estimates of the R number and forecasts for new cases of Covid-19, hospital admissions, and deaths due to Covid-19 using data that was publicly available as on 20th April 2021.
  • SAGE has declared that due to the “increasing localised nature to managing the epidemic, particularly between nations” the UK wide estimate is less useful. To enable comparison with SAGE estimates we report our estimates for England.  We will no longer be producing an R estimate for the UK as a whole.
  • Figure 1 shows that the Reproduction number, R, for England. R is the average number of secondary infections currently generated by an infected individual, and is estimated to be in the range of 0.80 – 0.90 based on specimen date data until 16th April.
  • For Northern Ireland the R number is in the range 0.95 – 1.10; for Wales, 0.80 – 0.95 and for Scotland, 0.80 – 0.90. The regional R number estimates given in Figure 6 show that, currently, the East Midlands has the lowest R number while the South West has the highest value across England’s regions.
  • Based on our model, by 17th May when step 3 re-opening is due to restart, we expect the trend value of daily cases to be around 600; admissions to be below 50, and deaths to be well below 25 (Figures 3-5).
  • To the extent that re-opening of the economy increases transmission, these numbers may be exceeded. At the same time, expansion of the vaccination programme can be expected to reduce transmission. The trajectory that nets out these opposing trends could become evident in the weeks to come.

“Based on the latest data on new cases, our estimate of the R number for England lies in the range 0.80 – 0.90, unchanged relative to last week. This estimate is based on data up to 20th April 2021, including about a week’s data following step 2 of the roadmap out of lockdown. Hospital admissions and deaths due to Covid-19 continue their steady decline.”

Dr Craig Thamotheram
Senior Economist - Macroeconomic Modelling and Forecasting