Covid Situation Report: May 9, 2024
Update on Covid providing information on positivity and hospital admissions for England and its regions. This post is best viewed using the browser or Substack app.
Introduction
This weekly Covid Situation report was originally posted on my substack ‘Seeing the Forest for the Trees’ where I publish articles on Covid and other topics. You can access my substack at the following link.
A reminder that not all of the data that was previously included in the situation update is now available on a weekly basis. Where relevant, changes to the content and data sources have been noted.
This week's article delves into the detailed daily Covid hospital data, which is now released monthly, and also includes the updates on new variants and the Spring 2024 booster campaign.
Summary
Overall, the past week’s data indicates that Covid levels are rising across all regions, especially among individuals aged 65 and older.
There has been another rise in the Covid positivity rate this week, while the rates for Flu and RSV continued to fall.
Weekly hospital admission rates for Covid have increased, but have now stabilised at low levels for Flu.
Over the past week, all regions have seen rises in weekly hospital admissions due to Covid. Weekly hospitalisation rates increased most for those aged 65 years and older and are getting high for those older than 85 years.
The monthly report on daily Covid hospital data shows a less significant increase in admissions but is not as up-to-date as the weekly admission rates.
A new variant, KP.2, has emerged which is quickly replacing the current JN.1 variants; however, early reports from the UKHSA show it does not have a significant relative growth advantage.
Considering the increasing Covid levels, the notable decline in vaccine efficacy after 15 weeks and the emergence of a new variant, a successful Spring 2024 booster campaign is important to protect the most vulnerable populations.
The Spring 2024 booster campaign, which began on April 15, has had a strong start, with over 2.3 million doses administered in the first three weeks!
As always, it’s important to remember that the risk of hospitalisation from Covid infection increases significantly with age and for those immunocompromised. Also ‘Long Covid’ remains a risk for all as shown by the recent ONS report. Therefore, it is prudent to take appropriate measures such as self-isolating when experiencing Covid symptoms and enhancing ventilation whenever possible.
Further analysis of the ONS data on Long Covid was covered in a recent article I posted which can be found here.
Status of main respiratory diseases in England
This section presents the latest data on positivity rates for primary respiratory infections in England. It is important to understand that positivity differs from prevalence, which refers to the overall percentage of COVID-19 in the general population. Appendix 1 provides a more detailed explanation of the difference and why positivity rates are a useful indicator of Covid infection levels
The chart below displays the test positivity rates for the main respiratory illnesses in England, including Flu, Covid, RSV, and Rhinovirus.
There was a continued rise in the Covid positivity rate to 8.6% this week. The positivity rate for flu once again fell and is now well below that of Covid. Additionally, the rates for RSV continued to fall although there was an increase for Rhinovirus.
The following chart shows hospital admissions per 100,000 people in England for the main respiratory diseases.
Weekly hospital admission rates for Covid continued to increase and are approaching the levels seen in early December 2023. Admissions for Flu have stabilised and are now at low levels.
The next panel chart in this section shows Covid hospital admissions per 100,000 people by region. Hover your cursor over one of the chart lines to display the admission rates for all regions.
Hospital admission rates have risen across all regions in the past two weeks, and are now the highest in the North West and London regions.
The final panel chart in this section shows Covid hospital admissions per 100,000 people by age. Each panel represents one age group and the title and lines are colour coded. The grey lines show all of the other age groups to provide context.
While all age groups have experienced significant declines from the winter peak, weekly hospital admissions for individuals aged 65 are continuing to rise.
It's important to note that while testing policies have been updated from April 1, 2024, the guidelines for testing patients showing Covid symptoms or when a positive result would change the patient's treatment remained unchanged. Consequently, the number of Covid hospital admissions should be a dependable indicator of the virus's prevalence in the community for the period shown in these charts.
Covid hospital admissions and bed occupancy
Starting April 2024, NHS England moved from a weekly to a monthly publication schedule for daily Covid data in hospitals. This section provides an overview of the most recent data, released on May 9, which covered the month of April. As a result, it does not include the most recent weeks data used in the prior section.
The following panel chart displays in red the daily count of Covid hospital admissions, including patients diagnosed with Covid post-admission for the period Apr 1, 2023 to Apr 30, 2024. The second panel indicates the number of beds filled by patients primarily being treated for Covid in blue, as well as those with Covid as a secondary diagnosis — termed as patients 'with' Covid.
The charts show that in the last two weeks of April there were very slight increases in the number of Covid hospital admissions and beds occupied by Covid patients. Nevertheless, numbers remain very low.
The number of beds occupied by Covid patients includes both those being treated primarily for Covid and those ‘with’ Covid as a secondary infection. Unfortunately, NHS England no longer publishes separate data for beds occupied by patients being treated primarily for Covid. As a guide, about 25% of patients occupying these beds were being treated primarily for Covid in March.
The next panel chart shows the daily hospital admissions and diagnoses per 100,000 individuals for England and its regions. The grey line in each of the regional panels shows the trend for England for comparison.
While rates remained low across all regions, there were increases in the last two weeks of April, particularly in the South West, London, and North East and Yorkshire regions.
In summary, the daily Covid hospital admissions and diagnostic data confirms the rises seen in the more up-to-date weekly admissions data. However, the increases are not as great and the numbers are lower than shown in the weekly hospital admission charts. This is probably due to the fact that they are reporting slightly different metrics, as the weekly hospital admissions figures do not include patients who are diagnosed with Covid while already in the hospital.
Variant Update
The virus responsible for Covid is still mutating, with new variants appearing all too frequently. Recently, a new variant named KP.2 has been detected and is currently circulating in the UK. The KP.2 variant, which evolved from the JN.1 lineage, is part of a family of variants often identified in reports as the FLiRT strain.
On May 1, a UKHSA Covid report estimated that KP.2 accounted for approximately 12% to 18% of UK Covid infections in samples tested from April 6 to 17, though the prevalence of KP.2 and its related KP.3 variant is likely to be much higher now.
In the past, new variants have often led to a rise in Covid infections, a trend that can be quantified by the variant's relative growth advantage. The UKHSA Covid report also provided early estimates of the growth advantage of the most prevalent variants found recently. The following chart depicts the relative growth advantage of the three most common variants currently in circulation in red, while the growth advantage of the three most common variants preceding the Winter 2023 wave is shown in green. The grey hatched areas represent the upper and lower bounds for the estimates.
Current estimates of the relative growth advantage among the main circulating variants in the UK do not indicate a significant advantage for any single one. However, these assessments are preliminary due to the early stages of KP.2's progression in the UK, and there is significant uncertainty, as indicated by the broad upper and lower bounds for the estimated growth advantage of KP.2.
The chart also illustrates the growth advantage of the primary variants that circulated in November 2023, represented in green for comparison. In November, the situation was quite different, with JN.1 exhibiting a significant growth advantage over all other variants. The relative growth advantage of JN.1 was undoubtedly a contributing factor to the surge in Covid infections observed in December and January.
While new variants can often result in higher Covid infection levels, they do not provide information about the magnitude of the increase, which is influenced by other factors such as population immunity levels and social interactions.
While it's difficult to be certain, it appears likely that any KP.2 wave will be less significant than the one experienced in the recent winter for the following reasons:
The lower estimates for the relative growth advantage of KP.2;
Current higher levels of population immunity from the Autumn 2023 booster campaign and infections over the winter;
Reduced indoor mixing with the approach of summer.
Spring 2024 Booster Campaign
The Spring 2024 booster campaign for people aged 75 years and over, those in care homes, and individuals aged 6 months and over with a weakened immune system started an April 15.
Considering the early signs of increasing, though still relatively low, Covid levels and the decline in vaccine efficacy after 15 weeks, a successful Spring 2024 booster campaign is important to protect the most vulnerable populations.
The following chart displays the weekly number of doses administered during the booster campaigns to date. The Spring campaigns are represented in green, the Autumn campaigns in brown, and doses administered outside of these campaigns are depicted in grey.
The chart shows a clear difference between the Spring and Autumn campaigns. The Spring booster campaigns are limited to those aged 75 years and older, those in care homes, and individuals with a weakened immune system. NHS England estimated that about 7.3 million people are eligible for the Spring campaigns. The Autumn booster campaign's eligibility criteria vary by age and include hospital and care staff, individuals in care homes, and those with weakened immune systems. NHS England estimated that 26 million people were eligible for the Autumn 2022 campaign and 20 million for the Autumn 2023 campaign.
Finally, the Spring 2024 booster campaign is progressing much faster than previous Spring campaigns with just over 2.3 million doses given in the first three weeks.
You can check to see if you are eligible and book a booster at the following link.
In conclusion
Despite the reduced level of data, the available information indicates that Covid levels are rising particularly in the older age groups.
A new variant, KP.2, is widely circulating although, at present, it does not appear to have a significant relative growth advantage over other variants in circulation.
The Spring 2024 booster is in high demand among eligible individuals, with over 2.3 million doses administered in the first three weeks.
As always, if you have any comments on this Covid Situation Report or suggestions for topics to cover, please post a message below.
Appendix 1. Test positivity rates and prevalence
Positivity rates are derived from the results of hospital laboratory tests conducted on patients exhibiting symptoms of respiratory diseases. Test positivity is the percentage of patients who test positive for Covid of the total number of patients tested. Since the individuals tested for this measure are not a representative sample of the general population it differs from prevalence, which is derived from a representative sample of the population.
Test positivity rates, while not directly estimating the number of Covid infections in the general population, can be a valuable indicator of the infection trend. The panel chart below compares the weekly test positivity rate among hospital patients with respiratory symptoms to the prevalence of Covid in the general population, as reported in the Winter Infection Survey.
The chart shows that the weekly test positivity rates for patients with symptoms of respiratory infections follows the same pattern as the prevalence for Covid reported by the Winter Infection Survey. Since the Winter Infection Survey is based on a representative sample of the general population this supports using test positivity as a useful indicator for infection trends.
Please keep up the excellent work.
"Considering the increasing Covid levels, the notable decline in vaccine efficacy after 15 weeks and the emergence of a new variant, a successful Spring 2024 booster campaign is important to protect the most vulnerable populations."
Would you able to post any more information/ data or links to research that cover this is more detail?
Again many thanks for this very useful report!
Is there more detail from the Winter Prevalence report?
You state that ‘Covid levels are rising particularly in the older age groups’, but is that conclusion based on hospital data alone? I would expect them to be more likely hospitalized, but not necessarily to be more susceptible to catching it due to their higher vax rates and maybe reduced contact numbers.
Generally it would be very interesting to know who exactly is catching Covid now, is it random or appearing more in certain sub-populations (say, by age, sex, occupation, vax status etc.)?
Is there good data from other (W European) countries that are comparable to UK?