Prof Francois Balloux, Professor of Computational Systems Biology and Director, UCL Genetics Institute, UCL, said:
“The latest PHE report largely confirmed and strengthened earlier evidence about the behaviour of the B.1.617.2 (delta) lineage. There have been over 33,000 cases of the delta variant reported in the UK over the last week, and the variant now represents over 90% of all cases of COVID-19 in the UK. Transmissibility of the delta variant in the community is estimated to be ~41% higher than for B.1.1.7 (alpha), with estimates for within-household transmission possibly even higher.
“People infected with the delta variant are more likely to be hospitalised. Though, hospitalisations and deaths remain low considering case numbers. The case fatality rate is currently down to 0.1% thanks the high vaccine coverage among the most vulnerable. Risk of infection by those vaccinated with one dose looks increased for the delta variant, but protection provided by two doses of vaccine seems largely unaffected. Despite this, there are some breakthrough cases and there have been some deaths in doubly vaccinated people.