The Delta variant now accounts for almost all of the UK’s coronavirus cases, according to Public Health England.
Some 33,630 cases of the strain were recorded in the last week and PHE said “the most recent data show 99% of sequenced and genotyped cases across the country are the Delta variant”.
Last week, the Delta variant made up 90% of COVID cases across the UK.
The Delta variant is thought to be 65% more transmissible than the Alpha (Kent) variant in households, according to PHE estimates.
Although previously dominant in the UK, the Alpha variant – blamed for the winter surge in cases – made up only 4,089 cases in the last week.
The risk of being admitted to hospital with the Delta variant of coronavirus is around double that of the Alpha variant, but two vaccine doses still provide strong protection against both.
Some 423 people have been admitted to hospital with the Delta variant since last week, taking the overall total to 806.
Of these, 527 were unvaccinated and only 84 of the 806 had received both doses – although it is unclear how long it had been since their second dose, as it takes a couple of weeks to build up protection.
It’s also unclear how high the case fatality rate is – or the proportion of people with the virus who go on to die – as deaths usually occur weeks after infection and the majority of cases have been in more recent weeks.