The SOLIDARITY PLUS Finland Long-COVID trial aims to assess the long-term effects of imatinib and infliximab, used during acute hospitalization due to COVID-19-infection, on long-COVID symptoms and quality of life (QoL) using questionnaires at six months, one and two years post-discharge. The primary research questions are whether imatinib or infliximab lower the risk of long-COVID symptoms and leads to better QoL in the long term. Objectives include: i) Long-COVID symptoms To investigate the effect of imatinib (vs. usual care only) and infliximab (vs. usual care only) on the occurrence of symptoms that have been associated with the long-COVID syndrome. The questionnaires will take place at six months, one and two years after the hospital admission. The questionnaire will be the same that has been used in the SOLIDARITY Finland Long-COVID trial on remdesivir. The questionnaire was developed by our multidisciplinary team of physicians, including the representation of multiple specialties such as general practice, lung diseases, neurology, internal medicine, rheumatology, genetics, and clinical epidemiology, and two patient partners. The symptom questionnaire - that will be completed by patients at one and two years - measures basic patient information (age, height, weight, smoking status, major comorbidity, and working status) and a wide variety of potential long-COVID-symptoms and their bother (1. Fatigue; 2. Attention deficits; 3. Memory problems; 4. Sleeping difficulties; 5. Depressive mood; 6. Anxiety; 7. Dizziness; 8. Headache; 9. Tinnitus; 10. Paresthesias; 11. Changes in taste/smell perceptions; 12. Postexertional malaise; 13. Palpitations; 14. Chest discomfort; 15. Nausea; 16. Skin rash; 17. Joint aches; 18. Muscle pains; 19. Continuous cough; 20. Respiratory tract mucous discharges). ii) Quality of life The EQ-5D-5L questionnaire will be used to compare patients' quality of life in imatinib, infliximab, and usual care arms. EQ-5D-5L questionnaire assesses the following domains: 1. Mobility; 2. Self-care; 3. Usual activities; 4. Pain and discomfort; 5. Anxiety and depression; 6. The visual analog scale of subjective perception of overall health. Additionally (at 1 or 2 years; depending on future funding and ethical approval decisions): * The Finnish healthcare registries (such as Statistics Finland Mortality Database, the HILMO Care Register for Health Care, and/or Digital and Population Data Services Agency (Finnish Digital Agency)) will be used to estimate long-term mortality and incidence of major comorbidity in treatment arms. * Lung function will be assessed using spirometry and diffusing capacity, as well as the six-minute walk test (6 mwt) in treatment arms. * Whole-genome genotyping will be performed for a genome-wide association study to investigate genetic correlates of long-COVID-19 -symptoms in treatment arms.