Fundamental differences in the immune response of adults and children may help to explain why children are much less likely to become seriously ill.

The innate immune response of children is better at fighting coronavirus, which might help explain why they are less likely than adults to become seriously ill from the disease, new research suggests. The study compared Covid infection in adults and children across multiple organs. Researchers found a stronger innate immune response in the airways of children, characterised by the rapid deployment of interferons, helped to restrict viral replication early on. According to the study, a less rapid immune response in adults meant the virus was better able to invade other parts of the body where the infection was harder to control. Interferons tell nearby cells to tighten their defences when there are viral or bacterial threats.