Covid vaccines appear to work just as well against the more transmissible Delta variant offshoot as they do on its ancestor, health chiefs claimed today.
A report by the UK Health Security Agency (UKHSA), which replaced the now-defunct Public Health England (PHE), showed jabs are around 81 per cent effective at stopping people infected with AY.4.2 getting symptoms.
For comparison, two doses are thought to block around around 83 per cent of all people falling ill with the original strain.
The UKHSA said the results do 'not suggest a significant reduction in vaccine effectiveness for AY.4.2 compared to Delta' and admitted the slight drop may be down to chance.
It found the strain has increased in prevalence to 23,830 cases in the UK as of Monday, the latest date data is available for. But the true count could be as much as 10 times higher because Britain is only sequencing a handful of infections.
The variant has now been found in all but a dozen corners of England and makes up one in ten new cases — doubling in the space of a month.
Despite data showing it is still outcompeting its ancestor, some scientists are now questioning how much more transmissible than Delta the subtype really is. Experts initially estimated the strain was 10 to 15 per cent more infectious.
Figures show while cases of the mutant strain are continuing to increase, its curve is flattening off. It is increasing slower than its predecessor did at this point after it was first sequenced.
Covid vaccines appear to be just as effective against the more transmissible Delta offshoot, early tests today showed. Graph shows: The cumulative cases for each Covid variant since the fifth case was reported including Delta (lilac) and AY.4.2 (red). While cases of the mutant strain are continuing to increase, its curve is flattening off. It is increasing more slowly than its predecessor did at this point after it was first sequenced
The variant was most prevalent in people aged 10 to 19 as of October 25, with 5,473 people in the age group having been infected with the strain. They were followed by 40- to 49-year-olds (2,433), 30- to 39-year-olds (2,015) and 20- to 29-year-olds (1,900)
Regionally, the South West had the highest number of AY.4.2 cases in the week ending October 18 — reflecting overall infection numbers — with 426 sequenced during the week
The above chart showed AY.4.2 accounted for a slightly higher proportion of cases in the latest week — one in ten — compared to two weeks ago — one in 13. Scientists said the slow rise was still compatible with a 10 per cent transmission advantage over Delta
The above map shows the 12 areas AY.4.2 was not detected in (white) over the two weeks to October 16, the latest available. It has spread to almost every area of England
The new Covid variant AY.4.2 has been found in 42 countries, but has been most prevalent in the UK, US, Denmark, Poland and Germany. This graph shows the percentage of AY.4.2 cases as a proportion of the country's total Covid cases. The UK has led case growth since the variant was fist identified in July, but in recent weeks Poland has eclipsed this, and there are signs Germany is also catching up
