#16,025
A month ago the UK was reporting under 2,000 new COVID cases each day, and seemed well on their way towards `Lockdown Exit Day', which was scheduled for June 21st. But the rise, and rapid spread of the Delta variant (B.1.617.20) has swiftly changed that trajectory, and yesterday the UK reported just over 11,000 new cases.
The last time the UK reported numbers like this, it was mid-February.
While its increased transmissibility seems well documented, there are conflicting reports on its severity, although some studies are suggesting a more than doubled risk of hospitalization with the Delta variant. Deaths - always a lagging indicator - have yet to rise appreciably with the Delta variant, although most of the hospitalized patients are relatively recent admissions.
With 95%-99% of new cases estimated to be due to the Delta variant, we should soon get a better handle on its severity.
All of this is being watched carefully - both here in the United States and around the world - as the Delta variant continues its world tour. Although estimated to comprise only 9.9% of U.S. cases today, it is growing at a rate that could make it dominant here in the next couple of months (see CDC: Delta Variant Rapidly Gaining Ground In the United States).
All of which makes what happens in the UK over the next couple of weeks potentially a harbinger of what we might see later this summer.
We begin our updates with this statement from the PHE:
Delta variant cases continue to rise
PHE’s weekly COVID-19 variant cases data show that numbers of the Delta (VOC-21APR-02) variant in the UK have risen by 33,630 since last week to a total of 75,953. The most recent data show 99% of sequenced and genotyped cases across the country are the Delta variant.
Data show an increased risk of hospitalisation with Delta compared to Alpha, although PHE’s analysis shows that 2 doses of vaccine gives a high degree of protection against hospitalisation, estimated to be more than 90%.
According to PHE’s latest variant technical briefing, as of 14 June, a total of 806 people have been hospitalised with the Delta variant, an increase of 423 since last week. Of these, 527 were unvaccinated, and only 84 of the 806 had received both doses.
PHE now publishes the number of deaths among people who have tested positive for Delta within the past 28 days. The case fatality rate remains low for Delta. However, deaths tend to happen some weeks after infection and the majority of cases were confirmed less than 28 days ago. It is therefore too early to judge the case fatality of Delta compared to Alpha or other variants.
The UK's latest risk assessment (June 18th) continues to express high confidence in the variant's increased transmissibility, and reports of reduced vaccine effectiveness (particularly after only 1 dose). VE against hospitalization with two shots appears `maintained'.
Delta is predominant. All analyses continue to support increased transmissibility and reduced vaccine effectiveness against symptomatic infection. The interplay between the current findings of increased risk of hospitalisation and preserved vaccine effectiveness against hospitalisation requires careful consideration. The clinical course of disease and severity of hospitalised illness also require further detailed assessment. It is too early to assess the case fatality ratio compared to other variants. The priority investigations are more detailed analysis of hospitalised cases, characterisation of the generation time, viral load and period of infectivity, and epidemiological studies of reinfections.
This being Friday, the UK has dropped a number of new technical reports on COVID, which can be accessed at the following links.
Technical briefing documents on novel SARS-CoV-2 variants.Updated: 18 June 2021Data reports on novel SARS-CoV-2 variants.Updated: 18 June 2021Genomically confirmed case numbers for SARS-CoV-2 variants of concern and variants under investigation.Updated: 18 June 2021
Risk assessments for SARS-CoV-2 variants.Updated: 18 June 2021
While we are enjoying the lowest levels of COVID in the United States since March of 2020, the recent reversal of fortune in the UK is a reminder of how fleeting victories in a pandemic can be. Variants can be game changers, and Delta appears to be the most formidable iteration of COVID to date.
Our big advantage is that we are running about one or two months behind the UK in the spread of the Delta variant, which gives us a little more time to act.
Vaccination, while apparently not quite as effective against the Delta variant, appears to reduce the risk of severe illness and hospitalization. But right now, less than half the country is fully vaccinated, and that gives the Delta variant plenty of room to run.
