A UCL-led review of test and tracing has revealed that children appear to be more than 50% less likely to catch SARS-CoV-2, the virus which causes Covid-19.
UCL also state that the evidence of how likely children are in transmitting the virus remains weak.
The findings are currently awaiting peer review and formal publication and will be important in decision making within government for the reopening of schools and lock down easing.
The study is the largest of its kind where a meta-analysis has been undertaken of more than 6,000 international studies in finding out the likelihood of children becoming infected with the disease.
Lead author Professor Russell Viner (UCL Great Ormond Street Institute of Child Health) said:
“There is an increasing amount of data now available on children and COVID-19, and this is the first comprehensive study to carefully review and summarise what we do and do not know about susceptibility and transmission.
“Our findings show children and young people appear 56% less likely to contract COVID-19 from infected others.
“Susceptibility is a key part of the chain of infection, and this supports the view that children are likely to play a smaller role in transmitting the virus and proliferating the pandemic, although considerable uncertainty remains.
“This new data provides essential evidence to governments around the world to inform their decision-making on whether to reopen schools and reduce or end lockdown measures.”
6,332 studies were screened where researchers identified 18 studies with useful data.
The analysis found that children and young people aged under 18-20 years of age had 56% lower odds of catching the virus than adults.
One conclusion was that children are less likely to play a role in transmission of Covid-19 at a population level as less children are likely to be infected in the first place.
Professor Viner added:
“It is well known that children and young people make up only a very small percent of confirmed clinical cases of COVID-19, in most countries, including the UK. Children and teenagers make up an even smaller proportion of severe cases or deaths.
“However, such data about confirmed infection among clinical cases tells us little about susceptibility or transmission – as most children have few, if any, symptoms and therefore many do not present for testing or come to the attention of doctors.
“To understand susceptibility and transmission it was essential we looked at studies which trace and test all the close contacts of those with infection and at studies which screen whole populations for infections and not just those with symptoms.”
Co-author Dr Rosalind Eggo, of London School of Hygiene and Tropical Medicine, said:
“The available evidence has been brought together in a systematic way to better understand SARS-CoV-2 infections of children.
“It suggests that children and young people are at lower risk of infection than adults and may therefore play a smaller role in the epidemic as a whole.
“This new evidence will help us better understand the possible effect of school reopening on transmission in schools and in the community.”