Covid Situation Report: May 30, 2025
Update on Covid providing information on prevalence and hospital admissions for England and its regions. This post is best viewed using the browser or Substack app.
Introduction.
This report belongs to a weekly series summarising the Covid situation across the UK's home nations.
This week's report covers the latest weekly test positivity rates and hospital admissions data for England, along with the most recent data for Scotland, Wales and Northern Ireland. An update on the Spring 2025 Covid booster campaign is also provided. Finally, this report summarises the latest information of the Covid NB.1.8.1 variant, recently declared a ‘variant under monitoring’ by the WHO, and it’s impact on Covid levels in Hong Kong and Singapore.
As mentioned last week, this report was delayed a day due to holidays. Next week’s report will return to it’s usual Thursday publishing date.
Summary.
This week the good news continues with all Covid data indicating low levels across England, Scotland, Wales and Northern Ireland.
Flu activity fell to very low levels in all Home Nations indicating that the Flu season is over.
In England this week, the Covid test positivity rate remained stable and at relatively low levels.
In Scotland, Covid hospital admissions and bed occupancy remain at very low levels. However, there has again been a slight increase in wastewater monitoring levels although it remains relatively low. Flu admissions continue at very low levels and are much lower than for Covid.
This week Covid hospital admissions in Wales increased very slightly but continued to remain relatively low. Admissions for Flu and RSV have virtually stopped.
In Northern Ireland, Some Covid indicators increased very slightly but activity remained at a low levels Flu activity fell to very low levels and RSV is at baseline activity levels.
Last week the WHO declared NB.1.8.1 (sometimes called Nimbus) a variant under monitoring, reporting in it’s May 23 Risk Evaluation that:
Despite a concurrent increase in cases and hospitalizations in some countries where NB.1.8.1 is widespread, current data do not indicate that this variant leads to more severe illness than other variants in circulation.
The NB.1.8.1 variant is rapidly becoming dominant in several countries across South-East Asia. It has been associated with increased Covid levels in Hong Kong and Singapore, although Covid activity in these countries appears to have peaked.
The NHS Spring 2025 Covid Booster campaign opened on April 1 and will run until June 17, 2025. In England, just under 3.5 million doses have been given to date, with 51% of those aged 75 years and older vaccinated. However, coverage remains low (24%) for individuals under the age of 75 years who are immunosuppressed.
Those eligible for free vaccinations on the NHS are:
adults aged 75 years and over;
residents in a care home for older adults; and
individuals aged 6 months and over who are immunosuppressed.
Bookings for Spring 2025 booster vaccinations can be made at the following link:
A reminder that for individuals not covered by the NHS, Covid and Flu vaccinations may be obtainable for a fee at local pharmacies.
As always, it’s important to remember that the risk of hospitalisation from Covid increases significantly with age and for the immunocompromised. Therefore, it is important to take appropriate measures such as self-isolating when experiencing Covid symptoms and enhancing ventilation or wearing masks whenever possible.
Status of main respiratory diseases in England.
Note that the UKHSA National flu and COVID-19 surveillance report has moved to a condensed summer report and released every two weeks and is not published this week.
Consequently, this weeks report only provides an update on the test positivity rate which is still published weekly on the UKHSA data dashboard.
This section only provides an update on the latest available data on Covid positivity rates for England. It is important to understand that positivity differs from prevalence, which refers to the overall percentage of Covid in the general population. Appendix 1 provides a more detailed explanation of the difference and why positivity rates are a useful indicator of trends in Covid infection levels.
The following chart shows the test positivity rate for all Covid tests taken, including those outside of hospitals, and is mapped against the UKHSA activity thresholds. The thresholds are based on the historical trend for Covid test positivity and, consequently, represent a relative risk. More details on this approach can be found in the Guide to Covid Surveillance Metrics.
The chart shows that the test positivity rate was unchanged and remained just below the baseline threshold of activity indicating a relatively low level of risk.
Scotland weekly hospital admissions and bed occupancy
Scotland continues to publish weekly data on hospital admissions and bed occupancy for Covid as well as wastewater monitoring data. The dashboard for Scotland’s data can be accessed here.
The following panel chart shows the most recent data for weekly Covid hospital admissions depicted in blue, together with the number of beds occupied by Covid patients, shown in orange. The number of occupied beds represent patients being treated for Covid as well as those being treated with Covid.
This week Covid admissions remained broadly stable and at low levels. However, the number of beds occupied by patients testing positive for Covid again fell slightly following the slight increase two weeks ago.
Scotland remains the only home nation that is monitoring Covid levels using wastewater sampling and the following chart shows the seven day average of Covid levels found up to May 23, 2025.
The wastewater sampling data shows that the high Covid levels observed at the start of August 2024 dropped significantly to very low levels in the first 3 months of 2025. However, there have been slight increases in the past few weeks although levels remain relatively low. It remains to be seen if this signals a summer wave as seen last year.
Finally, the following chart compares the weekly hospital admissions for the main respiratory viruses in Scotland.
The chart shows that flu-related emergency hospital admissions rose sharply in December and Public Health Scotland reported that this reached a record high of 1606 admissions for the week ending Dec 29. This surge placed a considerable burden on hospitals. However, Flu admissions have fallen significantly in the past weeks and are now at very low levels, well below those for Covid.
Wales Covid hospital admissions.
The following chart provides the trend for weekly hospital admissions in Wales up to week ending May 25, 2025.
Two weeks ago, hospital admissions for Covid in Wales fell to their lowest level in over two years. However, they have now returned to the slightly higher levels which are still historically low.
The following chart illustrates that hospital admissions for flu in Wales which were high during December and January have now fallen significantly and are have now very low.
Status of main respiratory diseases in Northern Ireland.
Recently Public Health Northern Ireland began issuing a combined surveillance report on influenza, respiratory syncytial virus (RSV), and COVID-19 to offer a comprehensive view of the epidemiology of these infections within Northern Ireland. The report, published every Thursday, can be accessed here.
The first chart in this section shows the test positivity rates in Northern Ireland for the main respiratory illnesses — Flu, RSV, and Covid.
The chart shows that Covid levels, depicted in purple, were stable and remained low this week. Positivity rates for Flu, shown in green, have continued to fall from the winter peak and are now at low levels.
The chart below presents the weekly count of hospital admissions for the main respiratory illnesses where the infection was contracted in the community, thereby excluding patients who contracted Covid while in hospital. It is important to note that the hospital admissions data for other home nations include patients who contracted infections in the hospital, making them not directly comparable to the data from Northern Ireland.
The chart shows that for most of 2024, the bulk of hospital admissions for respiratory infections stemmed from Covid. However, since November 2024 hospital admissions for Covid, indicated in purple, have been low.
Meanwhile, hospital admissions for the Flu, depicted in blue, increased significantly in December. However, Flu admissions have fallen from the December peak and are now very low, well below those for Covid.
Spring 2025 Covid Booster Campaign
The NHS Spring 2025 Covid Booster campaign opened on April 1 and will run until June 17, 2025. Those eligible are older people in care homes, individuals 75 years and older, the immunosuppressed aged 6 months and over.
The data in this section is only for NHS vaccinations and does not include privately administered doses.
The first chart in this section compares vaccine coverage for those aged 75 years and older in the three Home Nations where data is published. The date of the latest available data is in parenthesis after each Home Nations name.
The table chart shows that the increase in coverage for England is lower than in the other Home Nations and this means that Scotland now has a higher coverage for those aged 75 years and older than England.
The following chart shows the number of Covid vaccinations given by week for each of the booster campaigns in England.
The Spring 2025 booster campaign is progressing well with 3,597,118 doses administered in England to date. Although the weekly number of vaccinations administered in England is slowing down the total number vaccinated is comparable with previous Spring campaigns.
Further detail is available for England and the following table shows the progress for those aged 75 years and older, people in care homes, and individuals aged between 6 months and 74 years old that are immunosuppressed.
The table clearly shows that although coverage for those in care homes is progressing well, individuals under the age of 75 years who are immunosuppressed continue to have low coverage.
New Covid variants and rising levels in South-East Asia
Last week’s situation report highlighted rising levels of Covid in Hong Kong and Singapore. Although the initial reports from these countries did not attribute these increases to a new variant, last week the WHO designated that a new variant NB.1.8.1 (sometimes called Nimbus) a variant under monitoring.
In their NB.1.8.1 Risk Evaluation Report the WHO concluded that the present global health risk was low but uncertain. In reaching this conclusion the report states that:
NB.1.8.1 is growing rapidly compared to co-circulating variants. However, NB.1.8.1 exhibits only marginal additional immune evasion over LP.8.1. While there are reported increases in cases and hospitalizations in some of the countries, which has the highest proportion of NB.1.8.1, there are no reports to suggest that the associated disease severity is higher as compared to other circulating variants.
They also noted that ‘Currently approved COVID-19 vaccines are expected to remain effective to this variant against symptomatic and severe disease.’
The following panel chart shows the latest prevalence data for the NB.1.8.1 variant across a number of countries between Nov 25, 2024 to May 12, 2025. The grey bar indicates when data is not available for some countries.
It is important to note that countries use different methods to sequence variants and are therefore not directly comparable. For example, Hong Kong sequences samples from wastewater monitoring whereas England sequences positive test samples. Also there is a low number of samples sequenced making the numbers uncertain.
Despite these caveats, it can be seen that N.B.1.8.1 variant is growing fast in South East Asia and is probably the dominant variant by now. However, it has yet to take off in other countries.
Data from Hong Kong provides the most comprehensive picture available of the impact of N.B.1.8.1 on Covid activity and the following panel chart shows the recent trend for Covid test positivity, Covid levels in wastewater, and the impact on health as measured by the consultation rate.
The charts indicate that the recent peak in Covid activity has been reached and these key indicators are starting to fall. The latest COVID-19 & FLU EXPRESS report from Hong Kong states:
The latest surveillance data showed that the overall local activity of COVID-19 shows signs of declining from its peak, but remains at a relatively high level.
Singapore also publishes a less comprehensive Weekly Infectious Diseases Bulletin 2025 that includes data on the test positivity rate for people admitted to hospital for respiratory infections. The following chart shows the weekly trend in that test positivity rate.
The chart shows that test positivity increased in May 2025 as it did in the previous year. The latest weeks data shows that test positivity has continued to increase and is now approaching the levels seen last May. However, the rate of increase has slowed and this may indicate that the wave has peaked in Singapore.
There have also been some press reports that the N.B.1.8.1 variant is driving increased Covid activity in other countries. A recent article in the Conversation provides a great summary of the present situation in Australia and the potential impact of the N.B.1.8.1 variant.
Finally, while some cases were detected in the USA through airport monitoring, only a small number have since been reported in some states, including California, Hawaii New, Ohio, Rhode Island, Virginia, and Washington. As only a few cases have been detected in the U.S. so far, it doesn't yet register on the CDC's COVID-19 data tracking site of variants.
In conclusion
Although the amount of data currently being published has fallen, the information available for England show that Covid levels are at relatively low levels. Recent data also indicates that Scotland, Wales and Northern Ireland also at low levels of Covid.
The Spring 2025 booster campaign is in progress and by the end of last week just under 51% of those aged 75 years and older had been vaccinated in England.
Across all Home Nations, Flu levels are now very low. The Winter peak is over.
Last week the WHO declared NB.1.8.1 a variant under monitoring, but assessed the present risk to public health as low. This was because although it has a slight growth advantage over other variants circulating there was now evidence that it was a more sever illness.
Singapore and Hong Kong have recently seen significant increases in Covid activity driven by the NB.1.8.1 variant. However, there are some signs that the peak has been reached and levels are starting to fall, particularly in Hong Kong.
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 proxy for infection trends. However it is not possible to use test positivity to estimate prevalence.
Thanks so much for putting this really helpful information together for us all every week.
Thank you so much and thanks also for the variant update.