A study of European children with Covid-19 suggests deaths are extremely rare.
Four of the 582 children studied died, two of whom had known underlying health conditions.
Children's symptoms were generally mild. Some who tested positive had no symptoms, but about one in 10 in the study needed intensive care.
Doctors say the work is "reassuring", but more needs to be known about treatments for the seriously ill.
What did the study find?
Researchers led by a team at London's Great Ormond Street looked at 582 children aged from three days up to 18 years living in 25 European countries.
They all tested positive for Covid-19 during the initial peak of the pandemic in April and had been seen at one of 82 specialist healthcare centres for their symptoms.
A quarter had underlying health conditions.
Of the four deaths during the study (0.69%), none were in children under 10, and two of those who died had pre-existing health conditions.
More than half of the children studied were admitted to hospital, and 8% needed treatment in intensive care.
What symptoms did the children have?
Children commonly had a fever (65%), upper respiratory tract infection (54%), pneumonia (25%) and gastrointestinal symptoms (22%).
Some of the children (16%), most of whom were tested due to close contact with a known case, had no symptoms at all.
What are the implications?
The researchers say the death rate in children is likely to be "substantially lower" than that observed in the study, because those with mild symptoms would not have been tested or diagnosed at the time.
However, more data is needed to help doctors make decisions on the best treatment options for children who do get sick, they add.
Dr Marc Tebruegge, from the UCL Great Ormond Street Institute of Child Health in London, said overall the vast majority of children and young people experienced only mild forms of the disease.
"Nevertheless, a notable number of children do develop severe disease and require intensive care support, and this should be accounted for when planning and prioritising healthcare resources as the pandemic progresses," he said.
Children who were infected with other respiratory viruses in addition to Covid-19 were more likely to be admitted to intensive care.
"This could have important implications for the upcoming winter season, when cold and flu infections will be more common," said Dr Begoña Santiago-Garcia, from University Hospital Gregorio Marañón in Madrid, Spain.
The research is published in The Lancet Child and Adolescent Health journal.