The mutated form of coronavirus known as ‘Delta Plus’ is continuing to spread across England with 23 cases now reported in Aylesbury Vale.
The strain, officially named AY.4.2, spreads more easily than other variants and now accounts for more than half of analysed cases in the Torridge area of Devon.
Officials designated the strain a ‘variant under investigation’ on October 20.
The latest analysis included a total of 120 samples tested in the Aylesbury Vale in the week up to November 13 with 23 samples, 19.2%, found to be the Delta Plus variant.
Aylesbury Vale was ranked 61 of 317 local authorities in England with 1 equalling the highest percentage of AY.4.2 Delta Plus cases.
Scientists are still working out whether it is more transmissible or whether there are other factors helping it to spread.
Vaccines are proving as effective against Delta Plus as they are against other Delta variants, two separate studies have found.
And there is “no evidence of increased severity based on risk of hospitalisation or death”, the UK Health Security Agency (UKHSA) has said.
Preliminary findings from the Wellcome Sanger Institute, one of the research bodies that works with the UKHSA, show potential hotspots for the variant.
It analysed more than 36,000 positive Covid-19 tests from the week to November 13.
Torridge in Devon was found to have the highest proportion of Delta Plus cases, at 50.3%, followed by Mid-Devon at 38.1%.
The research is provisional, but gives more localised detail than the official figures published by the UK Health Security Agency.