New Covid-19 variants emerge as the genetic make-up of the virus naturally mutates over time.
This is not a new or unexpected phenomenon with RNA viruses – and is the reason why, for example, fresh flu vaccines are needed every year.
Scientists are monitoring these mutations as they could result in the coronavirus becoming more transmissible, as with the Delta variant, or at the very worst more deadly or resistant to vaccines.
The strains in the UK with the most potentially concerning changes are labelled "variants of concern" (VOCs), and include:
| WHO name | Scientific name | Location first identified | Number of new cases in UK 2-8 June |
| Alpha |
B.1.1.7 |
Kent, UK |
4,089 |
| Beta |
B.1.351 |
South Africa |
24 |
| Gamma |
P.1 |
Brazil |
19 |
| Delta |
B.1.617.2 |
India |
33,630 |
Data source: UK government website
As the table above demonstrates, the Delta variant is currently the dominant strain in the UK.
Nine other variants are currently on the government's watchlist, but these are all "under investigation".
The new Covid-19 mutation related to Delta that was declared a VOC by the authorities in India today has also been detected in the UK.
But scientists are warning that there is not yet enough data about the variant – dubbed 'Delta plus' or AY.1 – to tell whether it poses a significant threat.
