LONDON: Children and young people are far less likely than adults to get severe cases of COVID-19 infection, and death from the pandemic disease among children is exceptionally rare, according to UK research published on Thursday.

A study of COVID-19 patients admitted to 138 hospitals in Britain found that less than 1% were children, and of those fewer than 1% - or six in total - died, all of whom were already suffering serious illness or underlying health disorders.

"We can be quite sure that COVID in itself is not causing harm to children on a significant scale," said Malcolm Semple, a professor of outbreak medicine and child health at Britain's University of Liverpool, who co-led the work.

"The highest level message really has to be that (in children with COVID-19) severe disease is rare, and death is vanishingly rare - and that (parents) should be comforted that their children are not at direct harm by going back into school," he told a briefing.

Global data on the spread of the coronavirus pandemic shows that children and young people make up only 1-2% of cases of COVID-19 worldwide. The vast majority of reported infections in children are mild or asymptomatic, with few recorded deaths.

For this study, published in the BMJ medical journal, Semple's team looked at data from 651 babies and children under 19 who were hospitalised with COVID-19 between Jan. 17 and July 3.

The six children who died all had "profound comorbidity", the researchers said, and this was a "strikingly low" fatality rate compared with a 27% across all age groups - from 0-106 years - of COVID-19 patients hospitalised in the same period. While the overall risk of children getting severe COVID is "tiny", the researchers said, children of Black ethnicity and those with obesity are disproportionately affected, as previous studies in adults have found.

The study also showed that children can have a cluster of symptoms including sore throat, nausea, vomiting, abdominal pain, diarrhoea and rash alongside already-recognised COVID-19 symptoms of fever, breathlessness and cough.