Doctors have sought to reassure parents that there has been no increase in the severity of Covid-19 cases among children because of the new variant.
The Royal College of Paediatrics and Child Health (RCPCH) said children's wards are not seeing any "significant pressure" from Covid-19.
It comes after a London hospital matron told BBC Radio 5 Live of having a ward full of children with coronavirus.
Laura Duffel said the surge in cases was "much scarier" than the first wave.
Ms Duffel, who has been working on Covid wards since the beginning of the UK's epidemic and specialises in children's intensive care, told 5 Live's Chiles on Friday show that people were "wrong" to say busy hospitals were merely a reflection of normal winter pressures on the NHS.
"This wave has just hit us so fast. It's literally in the space of a week that this has gotten so bad," she said.
"It's very different and I think that's what makes it so much scarier for us. We have children who are coming in. It was minimally affecting children in the first wave - [but now] we have a whole ward of children here [and] 20- and 30-year-olds with no underlying conditions are coming in."
However, doctors denied that the virus is putting significant additional pressure on children's wards across the country.
Virus is rife - 'but not among children'
Prof Russell Viner, president of the RCPCH, said: "Children's wards are usually busy in winter. As of now we are not seeing significant pressure from Covid-19 in paediatrics across the UK.
"As cases in the community rise there will be a small increase in the number of children we see with Covid-19, but the overwhelming majority of children and young people have no symptoms or very mild illness only.
"The new variant appears to affect all ages and, as yet, we are not seeing any greater severity amongst children and young people."
Dr Ronny Cheung, a consultant paediatrician at Evelina Children's Hospital, in London, added: "I've been the on-call consultant in a London children's hospital this week. Covid is rife in hospitals, but not among children - and that is corroborated by my colleagues across London."
Prof Calum Semple said that he spoke to colleagues on intensive care units and "not one of them has seen a surge in sick children coming into critical care and we're not hearing of a rise in cases in the wards either".
"We're not seeing a different spectrum of disease in children, certainly we're not seeing a surge in cases," Prof Semple told BBC Radio 4's PM programme.
Dr Liz Whittaker, a consultant paediatrician at St Mary's Hospital London, said "only small numbers" of children who test positive for Covid develop severe disease and these are "within expected levels" at the moment.
"I continue to worry for my elders, not my kids," Dr Whittaker added.
Meanwhile, Dr Lee Hudson, from Great Ormond Street Hospital, said that none of his paediatric colleagues at hospital across London were reporting higher rates of sick children because of Covid but said that parents should never be afraid to seek medical help if they are worried about their children.