Hopes that wave of infections had peaked fade
July 23, 2021
This article has not been updated recently
According to ZOE COVID Study incidence figures, it is estimated that among unvaccinated people in the UK there are currently 36,250 new daily symptomatic cases of COVID on average, based on PCR and LFT test data from up to five days ago [*]. An increase of 19% from 30,572 last week. Comparatively there are currently 23,769 new daily symptomatic cases in partly or fully vaccinated people, an increase of 43% from 16,617 new cases last week. The overall number of estimated cases is 60,019, which indicates that new cases are still on the rise in the UK (Graph 1).
Last week, ZOE data reported a plateau in new COVID cases. This was based on the methodology at the time. As the ZOE app contributors continue to take full advantage of the vaccine rollout to help tackle the pandemic, the number of unvaccinated people in the dataset steadily declines. This is a situation that all the COVID-19 surveillance studies are facing. In response, the ZOE team has adjusted its incidence methodology to allow it to continue to report figures with confidence.
The updated methodology shows that the number of daily cases in the UK is still on the rise in both vaccinated and unvaccinated groups (Graph 2).
Graph 3 shows how the updated incidence figures compare to other COVID-19 surveillance studies (ONS, REACT-1 and confirmed cases).
In terms of prevalence, on average 1 in 96 people in the UK currently have symptomatic COVID (Table 1).
The UK R value is 1.1 and regional R values are; England, 1.1, Wales, 1.2, Scotland, 0.9 (Table 1). Across the regions, cases are rising in all regions with the exception of Scotland, where cases are actually falling. The pace of increase is slower in North West England and Wales.
The ZOE COVID Study incidence figures (new symptomatic cases) are based on reports from around one million weekly contributors and the proportion of newly symptomatic users who have received positive swab tests. The latest survey figures were based on data from 33,507 recent swab tests done between 3 July and 17 July 2021.
Tim Spector OBE, lead scientist on the ZOE COVID Study app and Professor of Genetic Epidemiology at King’s College London, comments on the latest data:
“Unfortunately, hopes that the current wave of infections had peaked have faded, as ZOE’s updated data shows new COVID cases continuing to rise as the UK lifts most restrictions. While COVID is less severe in the young and vaccinated population, it’s not definitely not going away anytime soon. We mustn't forget the lessons of the pandemic in our rush to return to ‘normal life’, as this will only prolong COVID’s grip on our lives. As the numbers rise many of us will not only have our lives disrupted with endless notifications to self-isolate but more people will be affected by Long COVID.
At ZOE, we maintain that the best way to stop the spread is to get vaccinated, familiarise yourself with the more than 20 possible symptoms of COVID and to test yourself for the disease when you don’t feel quite right. The UK is testing more people than almost any other country, but the question is - are we testing the right people?
To get some real data on the ‘pingdemic’, we’re now asking all ZOE contributors to let us know if they've been pinged by the NHS COVID-19 app, so we can analyse the risk profiles of those contacts. Anyone can join the ZOE COVID Study via the free app and as this pandemic continues to rapidly change, we will continue to update and adjust to make sure we keep pace.”
Professor Tim Spector explains how the methodology changes have impacted ZOE estimates at 4.18 into his latest video update on ZOE YouTube channel. More detail can be found at our blog.
Graph 1. The ZOE COVID Study UK Infection Survey results over time
Graph 2. UK incidence figures by vaccination status
Graph 3. New and previous methodology trend lines compared to ONS and REACT-1.
Table 1. Incidence (daily new symptomatic cases)[*], R values and prevalence regional breakdown table
Map of UK prevalence figures