Local and systemic responses to SARS-CoV-2 infection in children and adults

Local and systemic responses to SARS-CoV-2 infection in children and adults

The immune system that we are born changes and develops over our lifetime and it is these difference that can help explain why children are much less likely to become seriously ill with COVID-19. Through the use of powerful single cell analysis tools, our study showed that children have a much stronger and faster immune response in their airways, helping them to restrict viral replication early on in the disease at the site of infection and hence protecting them from disease progression. Whilst in the blood, we saw a greater number and variety of cytotoxic immune cells in adults compared to children. Although designed to detect and kill infected cells in order to protect the body, this is a finely tuned balancing act, and when left unchecked can result in further harm, such as damage to the lungs and other organs that is typical of more severe forms of COVID-19,