The UK Health Security Agency’s 8 October mpox surveillance update records cases through 30 September 2026, continuing a revised clade presentation introduced in August. Clade Ib has become more common than clade IIb in the country. The national figures place London at the centre of England’s regional picture but do not include a current London case total.
From August, the UK Health Security Agency’s reporting presentation separates confirmed clade Ib, confirmed clade IIb, recombinant clades and cases whose clade is not yet known. Earlier reports grouped cases with an unconfirmed clade alongside clade IIb. The change reflects an epidemiological shift: UK clade Ib case numbers increased during 2026 and exceeded clade IIb from July.
The new format is important when comparing figures across reports. A category described as “not yet known” should not be read as a new strain, while a change in how cases are grouped can affect apparent comparisons over time. The revised presentation gives readers a clearer separation of confirmed clades and cases still awaiting classification.
National figures through September
The cumulative UK total from 6 May 2022 to 30 September 2026 is 5,023 cases. That total includes 3,732 cases recorded in 2022 and 1,291 across 2023 to September 2026. In the latter period, 226 cases were classified as clade Ib, 972 as clade IIb and 93 as clade not yet known. These are different time spans and should not be conflated.
England accounted for 1,168 of the 1,291 cases recorded across the UK from 2023 to September 2026. Within England, 585 were presumed to have been acquired in the UK, 375 were presumed imported and 208 were awaiting classification. The remaining cases in that period were recorded in Northern Ireland, Scotland and Wales.
For September alone, England’s monthly dashboard lists 46 clade Ib cases, three clade IIb cases and 19 whose clade was not yet known. Those figures are for England, not London, and refer to the month commencing 1 September. They should not be presented as a London count or as a measure of prevalence at the time of publication.
London’s place in the picture
Across the period shown, most English cases were among people resident in London, although an increase was also seen in the north of England in early 2026. The overview does not provide a September London total, so the regional pattern cannot be converted into a precise local count.
London also remains prominent in the vaccination data. By 31 March 2026, 63,624 first doses and 42,902 second doses had been administered to men who have sex with men in London. These are dose counts, not numbers of distinct people or completed courses. Most doses across England were administered in London, and the figures combine information from two surveillance systems covering different periods.
The vaccination programme has changed over time. Reactive pre-exposure vaccination began in the UK in June 2022 for groups at higher risk of exposure. The national reactive offer ended in summer 2023, but continued in London and Greater Manchester in response to local transmission and case clusters. A routine national programme for men at higher risk attending specialist sexual health services began in England in August 2025.
Reading the figures carefully
The data are a surveillance snapshot, not a real-time count. The case tables were based on data extracted on 5 October, and later reports may include corrections arising from delayed reporting, updated patient information or removal of quality-assurance samples. Monthly case figures are assigned by specimen date.
There is also a distinction between confirmed and highly probable cases. Clade IIb totals include both confirmed cases and highly probable cases identified through orthopox testing, so the total may be slightly higher than a count limited to confirmed mpox. The surveillance assessment treats the likely effect as minimal, while retaining that classification caveat.
The figures describe reported cases and vaccine doses; they do not, on their own, establish the risk to any individual or explain why cases changed. The revised clade presentation and the September figures offer a more current national view, while the London data show the city’s continuing significance in both regional case patterns and vaccination activity.
