Weekly Update of England’s Coronavirus Figures: 22nd-28th 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 people 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: 22nd-28th March

Summary:

  • The weekly number of people testing positive decreased by 7.5% (from 32,512 cases to 30,080)
  • The weekly positivity rate for PCR tests decreased from 2.0% to 1.9%, meanwhile, the weekly positivity rate for LFD tests increased from 0.19% to 0.25%
  • The weekly number of people admitted to hospital decreased by 17.2% (from 2,338 admissions to 1,935)
  • The average number of people with coronavirus per day this week decreased by 24.1% (down from 5,149 people to 3,906)
  • The average number of people on ventilation with coronavirus per day this week decreased by 26.3% (down from 801 people to 590)
  • The weekly number of people dying from coronavirus (28-day cut-off) decreased by 44.0% (from 445 people to 249*)
  • The cumulative number of people vaccinated with their first dose increased by 8.6% (from 23,854,862 people to 25,903,782)
  • The cumulative number of people vaccinated with their second dose increased by 73.1% (from 1,621,547 people to 2,806,124)

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:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 1st April)

The rate of decline accelerated from -1.3% to -7.5% this week, meaning weekly case numbers fell from 32,512 to 30,080. We are now 92% down on January’s peak and 80% down on Lockdown 2.0’s peak. This decline is a welcome change from the ~1-2% declines we have had in the past two weeks. However, the report that details the weekly positivity rate for both PCR and LFD tests has not been released yet so we do not know if this decline is due to less testing and/or schools starting to break up for Easter. Warmer weather could also be playing a part, encouraging more outdoor socialising where the risk of coronavirus is far lower. Either way, it is a better week for cases and at least shows that reopening schools did not push R above 1.

Update:

With the PHE report now released, we can see that there was a slight decline in testing compared to the previous week, which could explain the slight decline in case numbers. In terms of positivity rates, PCR positivity fell from 2.0% to 1.9% (suggesting a marginal decline), however, LFD positivity increased from 0.19% to 0.25% (suggesting a marginal increase). What this may indicate is that in the settings where LFD testing is being used – schoolchildren and their households; workplaces – we are seeing a slight uptick in cases, but this is cancelled out by declining prevalence elsewhere.

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 28th March)

The rate of decline decelerated by a fair amount from -23.5% to -17.2% this week, meaning weekly hospital admissions decreased by 2,338 to 1,935. This puts us 93% down on January’s peak and 82% down on Lockdown 2.0’s peak. This deceleration seems connected to the flatlining of cases in recent weeks, however, the fact admissions are still declining a decent amount could be an indication of the vaccines working or the concentration of cases in younger people. Will be worth keeping an eye on this over the next few weeks to see the extent to which admissions track cases.

Nonetheless, if we continue to follow our current trajectory, we could still reach lower numbers by April and May though. A -17.2% decline would see us reach 1,098 weekly admissions by 12th April and 427 by 17th May. Yet this slower decline does mean that we would not reach the lowest levels we achieved last summer until the first week of June now – two weeks later than when we would with last week’s decline.

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 28th March)

This week the rate of decline stayed exactly the same at -24.1%, meaning the average number of people in hospital with coronavirus fell from 5,149 to 3,906. We are now 88% down on January’s peak and 73% down on Lockdown 2.0’s peak. It also means our projections remain unchanged. If we continue falling at our current rate, we would see an average of 1,708 people in hospital by 12th April and we would be on course to reach the lowest levels we saw last summer by the week of 17th-23rd May, around the same time as Phase 3 reopening.

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 28th March)

The rate of decline decelerated ever so slightly from -26.6% to -26.3% this week, meaning the average number of people on ventilation with coronavirus fell from 801 to 590. We are now 84% down on January’s peak and 53% down on Lockdown 2.0’s peak. It also means our projections looking forward remain basically unchanged too. If we continue falling at our current rate of decline, we could see an average of 236 people on ventilation by 12th April and we are on course to reach the lowest levels we saw last summer by the week of 17th-25th May – the same time as hospitalisations.

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 2nd April)

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 2nd April) 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 22nd-28th March currently stands at 234, giving us a 5-7.5% confidence range of 246-252. The middle point, 249 deaths, means the rate of decline is -44.0%, an acceleration on last week’s -35.6%. We are now 97% down on January’s peak and 90% down on Lockdown 2.0’s peak. If we continue falling at our current rate of decline, we would surpass the lowest levels reached last summer by the week of 12th-18th April.

VACCINATIONS

Here is a graph showing the weekly number of vaccinations carried out in England, first and second doses separately:

Data taken from the UK Government’s COVID-19 Dashboard: https://coronavirus.data.gov.uk/ (accurate to 28th March)

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 28th March)

In the week of 22nd-28th March, England administered 2,048,920 first doses and 1,184,577 second doses of the coronavirus vaccine. This represents a ~1 million decrease in first doses and a ~700k increase in second doses from last week’s totals. These weekly totals take our cumulative totals up to ~25.9m for first doses and ~2.05m for second doses – an increase of 8.6% and 73.1% respectively.

We are beginning to see the changing dynamic between first and second doses in the weekly totals now. Second doses are ramping up quickly to accommodate our fast vaccine roll-out, however, it is nice to see a decent amount of first doses (~2m) still given for the week. Yet with the vaccine supply expected to drop slightly in April, we could see the first dose totals drop further. Though it would be good if we can still administer ~1 million first doses a week just to keep things ticking along nicely.

Due to the unreliability in doses to be administered, it makes projecting very difficult. We will surpass the government’s second target of the first nine priority groups vaccinated (~27m) during the week of 29th March-4th April (this week), yet how quickly we can now vaccinate the non-priority groups given our supply constraints is more uncertain and depends largely on how many first doses can be administered each week.

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

Week 6: 1st-7th March

Week 7: 8th-14th March

Week 8: 15th-21st March

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