Data is collected for all children under 18 years old in Estonia who were diagnosed with COVID-19 between 27.02.2020 and 01.03.2024 (either with the ICD-10 codes U07.1/U07.2 and/or a positive SARS-CoV-2 test. The following data is collected for each patient: age at the time of COVID-19 diagnosis, gender, place of residence, and COVID-19 vaccination status.
In order to assess the severity of the disease, the following data is collected for each case: hospitalization due to COVID-19, length of hospitalization, need for intensive care, need for mechanical ventilation, fatal outcomes, and occurrence of long-term sequelae (post-COVID-19 condition and pediatric systemic inflammatory response syndrome). Additionally, data on any comorbid chronic and acute diseases of the children in the study group is collected. The outcome measures are compared across five different SARS-CoV-2 VOC periods: original, Alpha, Delta, Omicron BA.1/BA.2 and Omicron BA.4/BA.5.
