The coronavirus disease 2019 (COVID-19) outbreak has evolved with different waves corresponding to subsequent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mutations. While the most severe cases have been observed in the elderly and in individuals with underlying comorbidities, severe pediatric and young adult cases have been observed, as well as post-infectious inflammatory syndromes and persistent symptoms leading to long-COVID. This manuscript describes the experience of a pediatric respiratory unit during the first year of the pandemic and reviews the corresponding literature with a special emphasis on children and young people with underlying conditions, such as immunosuppression, sickle cell disease, and cystic fibrosis.