The new sub-variant, named Deltacron, combines mutations from both Omicron and Delta. The variant has been detected in multiple areas of France, and cases have doubled in China and tripled in parts of Australia.

In England there has been a surge in COVID-19 infections, with case numbers rising by 49.2% in a week. There has also been a rise of 20.9% in patients admitted to hospital for COVID-19-related illness in the past week. However, there has also been a decrease in fatality rates of 4.4%.

Currently only a small number of cases of the new variant have been identified and it is not yet known what level of protection vaccines will provide against this sub-variant.

Professor Adrian Esterman, Chair of Biostatistics at the University of South Australia, has said that the new Omicron sub-variant is up to six times more transmissible than the original strain of COVID-19. “Omicron BA.2 is about 1.4 times more infectious than BA.1. The basic reproduction number (R0) for BA.1 is about 8.2, making R0 for BA.2 about 12,” said Esterman, via his Twitter account.

When asked about the COVID-19 variant, UK health secretary Sajid Javid said: “There are variants that we would obviously keep under review. The most recent one of concern has been Omicron but we have successfully navigated our way through that as a country thanks to the response of the British people.”

Javid added: “There are also subvariants of Omicron and we’re not concerned about any of those at this time.”

An estimate from the Office for National Statistics (ONS) has shown that one in 25 people are infected with COVID-19.