According to health secretary Sajid Javid, the rise was part of “normal” life returning and BA.2 presenting as a more infectious strain.
The UKHSA discovered the new variant – known colloquially as Stealth Omicron – in December last year.
The UK Health Security Agency (UKHSA) has labelled it a “variant under investigation”.
Stealth Omicron could be responsible for causing approximately half of all new cases detected in England.
Former World Health Organisation (WHO) professor Adrian Esterman said it has a “reproduction number” of “about 12”.
He wrote on Twitter that this brings its infectivity close to measles.
While now becoming dominant in the UK, Stealth Omicron may struggle to stay for long, as public immunity quickly foiled a previous peak in Denmark.
