COVID-19 – identifying risk factors for severe disease or long-term complications in children

Children and adults respond differently to infection with SARS-CoV-2, the virus that causes COVID-19. Thankfully, most children do not experience serious symptoms, but the few who are admitted into hospital with severe disease have a much wider range of symptoms than adults – a rare condition known as Paediatric Multisystem Inflammatory Syndrome (PIMS). Dr Nazima Pathan of the University of Cambridge is aiming to improve understanding of the underlying biology behind why COVID-19 affects children and adults so differently. She hopes to uncover new clues that could lead to new ways to prevent and treat severe illness in children, reducing both the short and long-term impact of the disease on young lives.

How are children’s lives affected now?

While children can be infected with the virus SARS-CoV-2, most will have only mild symptoms or none at all. But some will develop severe COVID-19.

“A child may become critically ill and might need hospital treatment,” says Dr Pathan. “Thankfully, most will recover from their initial illness – but they could be left with lasting problems that impact on their long-term health and well-being.”

Adults with severe COVID-19 generally have breathing difficulties and lung failure, but children can experience a much wider range of symptoms including vomiting, diarrhoea, tummy pain and headache – suggesting there may be more widespread inflammation compared to adults. This widespread inflammation seen in children with severe disease is known as Paediatric Multisystem Inflammatory Syndrome (PIMS) and usually occurs several weeks after infection.

“We urgently need to gain a better understanding of how this virus affects children – including why severe disease is so uncommon and why they have a different pattern of symptoms to adults,” says Dr Pathan.

How could this research help?

“We aim to identify biological factors that can influence a child’s risk of severe COVID-19 and/or long-term complications from the illness that may affect their quality of life,” says Dr Pathan.

The researchers will collect lung, blood and faecal samples from children with moderate or severe COVID-19, monitoring their progress during and after hospital admission. They will then link data from laboratory analyses with information about how a child responds to treatment and compare the breadth of the inflammatory response in children with PIMS to that seen in children with milder symptoms.

“By combining biological and clinical data, we hope to identify risk factors that can affect disease severity and outcomes in children,” says Dr Pathan.

The team also expects to uncover new knowledge about why children with COVID-19 are more protected from the disease compared to adults – and why they have different symptoms.

“Our findings could lead to early, personalised treatment for children who are severely affected with COVID-19, giving them the best chance of a full and rapid recovery,” says Dr Pathan.

The data generated in this study is closely aligned with other national and international studies – and will provide an important resource for researchers working on current and future pandemics.