Knowledge and challenges of COVID-19 in the paediatric population

The SARS-CoV-2 pandemic has given us many reflections and an uncertain future. But it has also been an opportunity to open to new challenges in paediatric research. In Catalonia, a multidisciplinary research group (COPEDI-CAT) formed by hospital and primary care paediatricians and physicists from the Computational Biology and Complex Systems Unit (BIOCOM-SC) of the Polytechnic University of Catalonia was set up to answer some of the unknowns about SARS-CoV-2 infection in the paediatric age group. In a first study, at the beginning of the pandemic, we demonstrated that children and adolescents were not the driving force behind the spread of the virus: 70% of the positive cases were transmitted by a cohabiting adult and only 7.7% were index cases within the family nucleus. In another study on the transmission of the virus in school bubble groups, we found that 75% of the positive cases did not infect any of their peers. We also found that most of the children and adolescents were asymptomatic or had mild COVID-19 and were progressing favourably. Hospitalisations and complications are described but are very rare. In the fifth wave, the SARS-CoV-2 delta variant has affected significantly more children (20%) than in previous waves. Thanks to the effort and investment made, research has borne fruit and we now have effective and safe vaccines. Vaccines have put us in a much more optimistic scenario, but with all the scientific information available and with the predominant delta variant, it is inevitable to ask whether vaccination in children under 12 years of age could be of benefit to them and to the general population. At the moment, we have no results on efficacy, safety and immunity in this age group and, of course, no authorisation from international health organisations such as the WHO, EMA and FDA.

For now, we should insist on the responsibility of adults to be fully vaccinated before making decisions on vaccination strategies for the very young. It seems reasonable to delay and be cautious with vaccination in the population below 12 years of age.