Are holidays causing regional surges?

Written byZOE Editorial Staff

According to ZOE COVID Study figures, it is estimated that among unvaccinated people in the UK there are currently 15,099 new daily symptomatic cases of COVID on average, based on PCR test data from up to five days ago [*]. An increase of 18% from 12,830 last week. Comparatively there are currently 4,023 new daily symptomatic cases in partly or fully vaccinated people, an increase of 37% from 2,930 new cases last week (Graph 1 below). The data continues to show that the positivity rate is much higher in those with just a first dose, compared to those who are double vaccinated (Graph 2 below).

The ZOE COVID Study incidence figures (new symptomatic cases) are based on around one million weekly reporters and the proportion of newly symptomatic users who have received positive swab tests. The latest survey figures were based on data from 6,435 recent swab tests done between 6 June to 19 June 2021. The data excludes lateral flow tests.

In terms of prevalence, on average 1 in 264 people in the UK are currently estimated to have symptomatic COVID [1] (Table 1 below).

The UK R value is 1.1 and regional R values are; England, 1.1, Wales, 1.1, Scotland, 1.1 (Table 1 below). These are the lowest R values that have been seen since the third wave started in the UK. One of the highest R values is in the South West of England which appears to be driven by an increase in cases in Cornwall (map below).

According to the prevalence data by age, the number of cases in the 20-29 age group continues to rise, however cases in the age groups over 30 have begun to level off. (Graph 5 below).

According to our data, a small proportion of those who have been vaccinated still get infected. ZOE collected reports last week from 487 contributors who had an infection after two doses of the vaccine, and 284 who reported an infection after one dose. The following approximate risk factors for infection based on one, two or zero doses of the vaccination, have been recorded using the latest ZOE data:

Current risk of new daily COVID infection:

In the unvaccinated: 1 in 1,664
after 1 vaccine dose: 1 in 4,374
after 2 vaccine doses : 1 in 13,506

This data shows that when people have received both vaccinations they have much greater protection against COVID-19. ‍

The ZOE COVID Study Local Authorities' Watch list for Active Cases of COVID-19‍

The following are UTLA regions with the highest estimates of prevalence rates averaged over the past week. Please note, that the local authorities' watchlist is intended to be an early indication system of areas where cases might be rising, but these prevalence estimates might be volatile due to the limited amount of responders and positive cases in some areas.

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:

“ZOE COVID Study data this week shows rates in former hotspots, such as Scotland and the North West of England, continuing to plateau. At the same time, top UK holiday destinations like Cornwall are emerging as new areas with rapidly increasing cases. I think this is down to a number of factors, including the sudden influx of holidaymakers over half term, as well as the recent G7 summit and a previously unexposed local population. We need to remain vigilant of these UK holiday destinations as summer holidays approach, and ensure that we minimise outbreaks by following government guidelines.

Since early on in the pandemic, the data from the ZOE COVID Study has shown that there are over 20 different symptoms of COVID-19, not just the classic three: fever, cough and anosmia. The COVID-19 situation in the UK is different to last summer due to new variants and the vaccine roll out. We’ve found that the symptoms in younger people and post-vaccination are both different. People urgently need to know there are more than just the three classic symptoms. The top symptoms being currently logged in the Zoe app are; headache, runny nose, sneezing, fatigue and sore throat, which for many will feel more like a common cold. The earlier people can catch the infection, the quicker they can self-isolate until symptoms abate and stop the spread. We encourage anyone feeling under the weather to take a test as soon as they can and stay at home.”

Professor Tim Spector gives more detail in his weekly video update on YouTube here.

The app is delivered in collaboration with King’s Health Partners, an Academic Health Sciences Centre based in South East London.

Graph 1. Daily new cases of COVID in UK by vaccination status