As viruses evolve, they sometimes change. These changes are called ‘mutations’ or variants.
They can affect how the virus acts, such as how easily it spreads, or the severity of the disease.
The Delta variant of Covid-19 is currently the dominant variant of the virus in the UK. By 9 July 2021, the Delta variant accounted for approximately 99% of cases that are sequenced across the UK.
Data on new variants of the COVID-19 virus are collected and analysed to understand how they affect the behaviour of the virus.
The COVID-19 vaccines currently in use or approved are highly effective against the Delta variant after 2 doses. Vaccines are still a vital weapon in the fight against COVID.
Learn more about the effects of the virus variants on Covid-19 vaccines here