Today, we have published a new report on our real-time tracking of the COVID-19 pandemic. This information is helping the government to track the COVID-19 pandemic in real time.
We have highlighted the latest findings and provided interpretation of what these findings mean. We have also explained our recent model and report changes.
- The current estimate of the daily number of new infections occurring each day across England is 12,900 (5,890–27,500, 95% credible interval).
- The daily infection rate is highest in the East Midlands (EM), North West (NW) and West Midlands (WM) with 1,910, 2,540 and 1,680 new daily infections, corresponding to 40, 35 and 28 per 100,000 population, respectively. Note that a substantial proportion of these daily infections will be asymptomatic.
- We predict that the number of deaths occurring daily is likely to remain low with a forecast for the period around the 16th April suggesting that there will be fewer than 175 deaths per day and potentially as few as 35 deaths per day.
- The probability of Rt exceeding 1 is 64%, 63% and 62% in the NW, EM and WM, respectively; 41% in the in the East of England (EE) and North East (NE); around 30% in Yorkshire and Humber (YH) and South East (SE); and approximately 15% in London and South West (SW).
- The growth rate for England is estimated to be positive at 0.02 (-0.02–0.05, 95% credible interval) per day. This means that, nationally, the number of infections is increasing, although there is heterogeneity across regions, with negative growth in some regions.
- London, followed by the WM, NW and EE, continues to have the highest attack rate, that is the proportion of the population who have ever been infected, with 38%, 31% and 25% respectively. The SW continues to have the lowest attack rate at 10%.
- Note that the deaths data used are only very weakly informative on Rt over the last two weeks. Therefore, the estimate for current incidence, Rt and the forecast of daily numbers of deaths are likely to be subject to some revision.
The plots of the estimated Rt over time are showing an increase, following a period of downwards trends from the introduction of the national lockdown in January. The Rt for some regions are around 1 (EM, NW, WM), although these estimates are quite uncertain and the upper bounds include values much higher than 1. This anticipated increase in the Rt is mostly driven by the school reopening from March 8th, the impact of which will not yet have filtered through to the data on deaths.
The incidence of deaths has continued to fall sharply in all regions and it is predicted to plateau at low values, with some initial evidence of a resurgence in the northern regions. This pattern is also shared by the estimated number of new infections, with a potential increase in the Midlands and northern regions.
The plot of the infection fatality rate (IFR) shows an increasing mortality risk from September onwards (at least in the over-45s) until the immunisation programme begins to show an impact. At the end of January we estimate a decreasing IFR in all adult age groups, but most steeply at older ages. The overall IFR falls to about 6-7% in the over-75s and 0.3% overall.
Other indicators (e.g. hospital bed prevalence, reported new cases) continue to suggest a declining epidemic. Prevalence of disease is now around 0.25% in England with high regional heterogeneity. Some evidence for a resurgence in transmission is evident in the ONS Community Infections Survey, where prevalence is increasing in secondary school age children and in the North East and Yorkshire in particular.
Additional comment from lead researcher – Professor Daniela De Angelis, MRC Investigator and Deputy Director
The pandemic has been shrinking in England as a consequence of the January lockdown and signs of the impact of immunisation on the risk of mortality are becoming apparent. However, there is regional heterogeneity. There is initial evidence of transmission increasing in some regions after the reopening of schools; vaccine uptake and proportion of the population that has ever been infected (so with infection-acquired protection) varies regionally; and trends in disease prevalence from the ONS are also different between regions. The impact of the steps of the roadmap needs careful monitoring.
Model and report changes
- The model has the ability to incorporate estimates of community prevalence, by region and age group, from the Office of National Statistics COVID-19 Infection Survey (see Data Sources for details). These are included weekly over the last 8 weeks and for the age groups >4 years to inform trends in incidence that are too recent to be captured by the data on deaths. In recent weeks we have been using these data, but do not include them in the analysis here due to the difficulty in resolving conflicting signals coming from the two datasets.
- The model now accounts for the ongoing immunisation programme, stratifying the population of people still susceptible to infection with the virus according to their immunisation status (unimmunised/1 dose/2 doses). We use data on the daily proportions of the population getting immunised to inform this splitting of the population, assuming that it takes three weeks for vaccine-derived immunity to develop .
- The geographical definition has been changed from the seven NHS regions (map) to the nine regions typically used in government (map). This new spatial definition more appropriately reflects the existing regional heterogeneity.
- Using observations of improved survival in hospitalised COVID-19 patients, we have allowed the probability of dying following infection with SARS-CoV2 (the infection-fatality rate, IFR) to gradually change over the course of June 2020, with a decrease being estimated. More recently, the Kent variant of the virus has gradually become the predominant virus strain and we accordingly allow for a change in the IFR over the period in which the relative prevalence of this strain has been growing.
- The ‘Epidemic summary’ now only reports the current value for the IFR by age. To visualise how this has changed over time in our model, see the IFR tab in the ‘Infections and Deaths’ section of the report. The quantity that is now plotted under this tab is the probability of dying if infected, taking into account the impact of the immunisation programme.
- The modelling now accounts for a different susceptibility to infection in the under-15s, using information from literature (Viner et al, 2020) suggesting that children less likely to acquire infection when in contact with an infectious individual.
Contact for media enquiries
Alison Quenault, Communications Manager at MRC Biostatistics Unit, University of Cambridge