Figures show that there were 15 patients been treated for Covid-19 the week ending June 5, which more than doubled to 33 the following week, ending June 12.
The 120% rise in just a week comes amid growing concern over two Omicron sub-variants, BA.4 and BA.5.
Every region of England is now seeing increasing numbers of people being admitted to hospital with Covid-19, official figures show.
In the North East and Yorkshire, 770 people were admitted in the week to June 14, up 120% from the previous week.
Most cases in the UK are still caused by the Omicron BA2 variant, originally dubbed ‘Stealth Omicron’, UK Health Security Agency (UKHSA) data shows
But health chiefs are monitoring the impact of the variants Omicron BA.4 and Omicron BA.5, which were designated variants of concern in the UK on May 20.
Dr Mary Ramsay, Director of Clinical Programmes at the UKHSA, said: “After a period of low case rates, we are now seeing increases in outbreaks within care homes and in hospitalisations among those aged 80 years and over.
“It is encouraging that we are not seeing an increase in intensive care unit (ICU) admissions but we are monitoring data closely and assessing the possible impact of subvariants BA.4 and BA.5.
“As we enter summer, it’s still important to remember that Covid-19 has not gone away and to get vaccinated to reduce the risk of becoming seriously ill with the virus. If you’re not yet up to date with your jabs please come forward now – it’s not too late to get protected.
“Remember to observe good hand and respiratory hygiene. It is also sensible to wear a face covering in crowded, enclosed spaces. If you have any symptoms of a respiratory infection, and a high temperature or feel unwell, try to stay at home or away from others – especially elderly or vulnerable people.”