Weekly Update of England’s Coronavirus Figures: 1st-7th March

This piece is part of a series of weekly blog posts that aim to summarise England’s progress throughout lockdown, showing (1) how far we have come; and (2) how far we could go if we maintain our current rates of decline. It provides an updated summary detailing the weekly change in:

  • Positive cases (by specimen date)
  • Hospital admissions
  • People in hospital with coronavirus (average across the week)
  • People on ventilation with coronavirus (average across the week)
  • Deaths (by date of death)
  • The cumulative number of people vaccinated (first and second dose separated)

Because of the data used, the weekly update will come in stages:

  • Monday – Vaccinations, people in hospital, and on ventilation
  • Tuesday – Hospital admissions
  • Thursday – Cases (by specimen date)
  • Friday – Deaths (by date of death)

This is due to the length of time it takes for the each dataset to become complete. Some of the data takes longer (four to five days) because of using the specimen date for cases (the date the test was carried out rather than reported) and date of death for deaths (instead of date reported). The reasoning why these measures are used instead of the daily reported figures is because they give us a more accurate picture of what is happening in the community on any given day, whereas reported figures consistently oscillate between underreporting or overreporting infections and deaths, making it difficult to fully trust trends in its data.

WEEKLY UPDATE: 1st-7th March

Summary:

  • The weekly number of people testing positive decreased by 27.0% (from 45,898 people to 33,521)
  • The weekly positivity rates for both PCR tests and LFD tests decreased to 2.5% and 0.17% respectively (down from 3.6% and 0.17%)
  • The weekly number of people admitted to hospital decreased by 28.2% (from 5,666 admissions to 4,066)
  • The average number of people in hospital with coronavirus per day this week decreased by 26.1% (from 12,377 people to 9,143)
  • The average number of people on ventilation with coronavirus per day this week decreased by 21.7% (from 1,859 people to 1,456)
  • The weekly number of people dying from coronavirus (28-day cut-off) decreased by 35.5% (from 1,522 people to 982*)
  • The cumulative number of people vaccinated with their first dose increased by 10.5% (from 17,212,804 people to 19,015,497)
  • The cumulative number of people vaccinated with their second dose increased by 32.9% (from 599,935 people to 797,321)

POSITIVE CASES

Here is a graph showing England’s weekly positive cases and where we could end up if we continue to follow our current trajectory:

Though the rate of decline decelerated from -30.5% to -27.0% this week, it still represents a significant fall in case numbers. England’s weekly total decreased from 45,898 cases to 33,521, putting us 91% down on January’s peak and 78% down on Lockdown 2.0’s peak. If we continue falling at a 27% decline, we would be down to ~9,500 weekly cases by 29th March (ahead of Phase 1B reopening) and ~5,100 weekly cases by 12th April (ahead of Phase 2 reopening).

Though schools resumed in full on Monday, we are yet to know what effect (if any) this will have on case numbers. We should know more in a couple weeks time. However, in anticipation of this, I have begun including our weekly positivity rates below. This now becomes a more important metric than total case numbers given that we are conducting hundreds of thousands more tests to catch asymptomatic people in educational and professional settings.

POSITIVITY RATE

Here is a graph showing England’s weekly positivity rate for both PCR and LFD tests:

Data taken from Public Health England’s Weekly Surveillance Reports: https://www.gov.uk/government/statistics/national-flu-and-covid-19-surveillance-reports (March 11th edition)

As we move into the next phase of our pandemic strategy (conducting mass testing in certain settings – i.e. schools, universities, factories – while relaxing restrictions), it is important to situate positive cases against positivity rate as it will help smooth out bumps in the data as it starts getting noisier. The World Health Organisation argues that a positivity rate of under 5% shows that a country has the virus under control. In England, we are comfortably under this threshold now, with both positivity rates for PCR tests and LFD tests standing at 2.5% and 0.17% respectively. I will be including this graph in my weekly updates from now on so that we can keep an eye on how it changes over time as more restrictions are loosened. This metric will be the most helpful at ascertaining whether the prevalence of the virus in the community is continuing to decline or starting to increase again.

HOSPITAL ADMISSIONS

Here is a graph showing England’s weekly hospital admissions and where we could end up if we continue to follow our current trajectory:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 9th March)

After a significant acceleration last week, the rate of decline decelerated slightly from -29.1% to -28.2% this week. It meant weekly hospital admissions decreased from 5,666 to 4,066. This puts us 84% down on January peak and 62% down on Lockdown 2.0’s peak. Our current trajectory still puts us on course to reach far fewer admissions for Phase 1B and 2 relaxations though. If we continue falling at our current rate of decline, we would reach ~1,090 weekly admissions by 29th March and ~560 by 12th April.

PEOPLE IN HOSPITAL WITH CORONAVIRUS

Here is a graph showing the average number of people in hospital with coronavirus in England and where we could end up if we continue to follow our current trajectory:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 8th March)

This week, the rate of decline accelerated from -21.5% to -26.1%, meaning the average number of people in hospital with coronavirus fell from 12,377 to 9,143. We are now 73% down on January’s peak and 36% down on Lockdown 2.0’s peak. This significant rate of decline also spells good news for our late March and early April projections. If we continue falling at current rate, an average of 2,727 people would be in hospital on 29th March, with this decreasing to 1,489 by 12th April. This would put us in a great position heading into late spring / early summer.

PEOPLE ON VENTILATION

Here is a graph showing the average number of people on ventilation per day with coronavirus and where we could end up if we continue to follow our current trajectory:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 8th March)

The rate of decline accelerated from -20.1% to -21.7% this week, meaning the average number of people on ventilation with coronavirus fell from 1,859 to 1,456. This puts us 60% down on January’s peak and we should drop below Lockdown 2.0’s peak next week, which would be great news as this is the last metric yet to do so. The rate acceleration has improved our projections moving forward too. By 29th March, we should see an average of 547 people on ventilation, meanwhile, by 12th April, we could see this number falling to 336. As ever, these projections are contingent on us continuing to fall at our current rate of decline.

DEATHS

Here is a graph showing the weekly number of people dying from coronavirus in England within 28 days of a positive test (by date of death), and where we could end up if we continue to follow our current trajectory:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 12th March)

Before giving detail on this week’s numbers, I want to explain the difficulty of tracking deaths (by date of death). They are more time-lagged than cases, which means we tend to see a high number of revisions, even after the 4-5 days typically given to count the dataset as complete. Though it varies week-to-week, these revisions typically tend to be around 5-7.5%. To account for this, I create confidence intervals based on 5-7.5% of the weekly total (as of 12th March) and then use the middle figure to calculate the week-on-week percentage change. This means that deaths are more of an estimate than the others, but it is accurate enough to gauge how well we are doing.

The weekly total of deaths for 1st-7th March currently stands at 924, giving us a 5-7.5% confidence range of 970-994. The middle point, 982 deaths, means the rate of decline is -35.5%, a deceleration on last week’s -38.9% but still comfortably over >30%. We are now 88% down on January’s peak and 64% down on Lockdown 2.0’s peak. At our current rate of decline, we would effectively reach the lowest levels seen during last summer by the middle of April.

VACCINATIONS

Here is a graph showing the culminative number of people vaccinated with their first dose in England and where we could end up if we continue to follow our current trajectory:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 8th March)

In the week of 1st-7th March, we vaccinated 1,802,693 people with their first dose – a decrease of 452,037. Though this decrease is disappointing, it is expected given that the amount of people receiving their second dose of the vaccine is now starting to increase more substantially. This week, England administered 197,386 second doses – its highest so far and more than double last week’s 86,500. As our vaccination success will rely on accommodating large quantities of both first and second doses, I have added the cumulative total of people with two doses on the main vaccination graph (the yellow block). I will also be including a new graph, which shows the weekly totals of first and second doses administered in England. You can see it below:

The expectation is that, throughout March, we will start to see the weekly totals for second doses increase rapidly, reflecting the fast roll-out of first doses administered in December and January. However, the challenge for the government is to achieve this ramp-up while also maintaining high volumes of first doses administered, so that we can continue vaccinating the population at a quick rate ahead of Phase 2, 3 & 4 relaxations. Ministers appear confident of meeting demand during this new phase of our vaccine strategy, but it will be worth keeping an eye on both graphs over the next few updates.

In terms of the cumulative total, for first doses, it increased by 10.5% this week, up from 17,212,804 people to 19,015,497. Given the slower weekly total administered, it has pushed back the projection for reaching the second government target of ~27 million to the week of 29th March-4th April. Though this would still be a great achievement ahead of the second easing of restrictions on 29th March.

PREVIOUS WEEKLY UPDATES

Week 1: 25th-31st January

Week 2: 1st-7th February

Week 3: 8th-14th February

Week 4: 15th-21st February

Week 5: 22nd-28th February

4 thoughts on “Weekly Update of England’s Coronavirus Figures: 1st-7th March

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