The risks of serious illness in children were found to be very low in the largest study to date

The risk of serious illness and death from SARS-CoV-2, the virus that causes COVID-19, is extremely low in children and adolescents, according to the most comprehensive analyzes of public health data, led by a team of researchers including Dr. Rachel Harwood from the University of Liverpool.

However, catching COVID-19 increases the likelihood of serious illness among the most vulnerable young people, those with pre-existing health conditions and severe disabilities, although these risks remain generally low.

The preliminary results, published in three new pre-printed studies from UCL and the universities of Liverpool, Bristol and York, will be submitted to the United Kingdom’s Joint Committee on Vaccination and Immunization (JCVI), Department for Health and Social Care (DHSC) and the World Health Organization (WHO), to inform vaccination and protection policy for those under 18. The studies did not examine the impact of a long COVID.

A preprint study, posted on the medRxiv server, found that 251 young people under the age of 18 in England were admitted to intensive care with COVID-19 in the first year of the pandemic (until the end of February 2021) .

Researchers, seeking to determine the absolute risk, said this equated to young people of this age group in England having an approximately 50,000 chance of being admitted to intensive care with COVID-19 during that time.

Looking separately at PIMS-TS, a rare inflammatory syndrome in children caused by COVID-19, researchers found that 309 young people were admitted to intensive care with the disease, which equates to an absolute risk of one in 38 911.

A related preprint study, posted to the ResearchSquare server and examining the data for England, concluded that 25 children and young people had died from COVID-19, which equates to an absolute risk of death from COVID-19 d ‘one in 481,000, or about two in a million.

Lead author of two of the studies, Professor Russell Viner (UCL Great Ormond Street Institute of Child Health), said: “These new studies show that the risks of serious illness or death from SARS-CoV-2 are extremely high. weak in children and youth. people.

“These higher risk youth are also at greater risk of contracting a winter virus or other disease, meaning youth with multiple health conditions and complex disabilities. COVID-19, however, increases the risks for people in these groups to a greater degree than for illnesses such as the flu (seasonal flu).

“Our new findings are important as they will inform protection guidelines for young people as well as decisions about immunization of adolescents and children, not only in the UK but internationally.”

Lead author Dr Joseph Ward (UCL Great Ormond Street Institute of Child Health) said: “Factors linked to a higher risk of severe COVID-19 appear to be broadly consistent for children and adults. Our study has found a higher risk of ICU admission among black youth compared to whites, as well as youth with health conditions such as diabetes, asthma and cardiovascular disease.

“These conditions were also risk factors for other illnesses leading to ICU admission, but to a lesser extent than for COVID-19.”

Lead author of the third preprinted study, Dr Rachel Harwood (University of Liverpool) said: “Our meta-analysis found similar risk factors to the other studies, although we also found that obesity increased the risk of serious illness from COVID-19. , something that we have known for some time in adults, but which is only now becoming evident as a significant risk in children and youth. “

Lead author Dr Clare Smith (University of Bristol) said: “We have found that only 40% of children and young people who tested positive for COVID-19 at the time of death actually died from COVID-19 , stressing that the risks are lower than simple numbers might suggest. Children and young people with complex neurological disabilities were at the greatest risk of death. “

Lead author Professor Lorna Fraser (York University) said: “It is important to remember that the risks are very low for all children and youth. Even when we found higher risks for some groups with severe medical conditions, those risks were still very low. compared to the risks observed in adults.

Dr Elizabeth Whittaker (Imperial College London) said: “It is reassuring to see that these results reflect our clinical experience in the hospital – we are seeing very few critically ill children. While this data covers up to February 2021, that hasn’t changed recently with the Delta Variant. We hope that these data will be reassuring for children and young people and their families.

The UCL-led study looked at hospital admissions data in England for young people between 2015 and 2021 and linked it to data on ICU admissions, deaths and PCR testing.

By examining the pre-pandemic data, the researchers were able to compare the risk of severe illness from SARS-CoV-2 in young people to their risk of severe illness from all other causes and influenza in particular.

In a separate preprint study, researchers looked at data from the National Child Mortality Database (NCMD), a mandatory reporting system in England, to identify all children and youth who died from SARS-CoV infection. -2 until the end of February 2021. Sixty-one children died as a result of a positive diagnosis, but researchers examined clinical records to determine that only 25 of them children (41%) died from COVID-19.

Meanwhile, a related third preprint paper released this week examined 81 existing studies assessing risk factors for severe illness and death from COVID-19 in young people. He found higher risks in young people who were obese, had more than one health problem, or had a heart or neurological problem. The risk, especially the risk of death, was higher in these analyzes than in the English national data. The authors suggested that this likely reflected biases in the published literature, but also the inclusion of studies from resource-poor settings with higher mortality.