Immune responses to SARS-CoV-2 infection and vaccination in children

During the three years since SARS-CoV-2 infections were first described a wealth of information has been gathered about viral variants and their changing properties, the disease presentations they elicit and how the many vaccines developed in record time protect from COVID-19 severe disease in different populations. A general theme throughout the pandemic has been the observation that children and young people in general fare well, with mild symptoms during acute infection and full recovery thereafter. It has also become clear that this is not universally true, as some children develop severe COVID-19 hypoxic pneumonia and even succumb to the infection, while another group of children develop a rare but serious multisystem inflammatory syndrome (MIS-C) and some other children experience prolonged illness following acute infection, post-COVID. Here I will discuss some of the findings made to explain these diverse disease manifestations in children and young people infected by SARS-CoV-2. I will also discuss the vaccines developed at record speed and their efficacy in protecting children from disease.