inclusion criteria: * all patients registered with informed consent from participating cohorts aged ≥18 years * additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: * all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years * patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. * covid-19 vaccination recommended by treating physician inclusion criteria for 2. sub protocol (observational study): * third covid-19 vaccination recommended by treating physician and administered in the frame of clinical routine inclusion criteria for 3. substudy. - patients receiving a new bivalent (wuhan/omicron ba.1) mrna sars-cov-2 vaccine in the frame of clinical routine, according to the treating physician

inclusion criteria: * all patients registered with informed consent from participating cohorts aged ≥18 years * additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: * all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years * patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. * covid-19 vaccination recommended by treating physician inclusion criteria for 2. sub protocol (observational study): * third covid-19 vaccination recommended by treating physician and administered in the frame of clinical routine inclusion criteria for 3. substudy. - patients receiving a new bivalent (wuhan/omicron ba.1) mrna sars-cov-2 vaccine in the frame of clinical routine, according to the treating physician

inclusion criteria: all patients registered with informed consent from participating cohorts aged ≥18 years additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. covid-19 vaccination recommended by treating physician inclusion criteria for 2. sub protocol (observational study): third covid-19 vaccination recommended by treating physician and administered in the frame of clinical routine inclusion criteria for 3. substudy. - patients receiving a new bivalent (wuhan/omicron ba.1) mrna sars-cov-2 vaccine in the frame of clinical routine, according to the treating physician

inclusion criteria: all patients registered with informed consent from participating cohorts aged ≥18 years additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. covid-19 vaccination recommended by treating physician inclusion criteria for 2. sub protocol (observational study): third covid-19 vaccination recommended by treating physician and administered in the frame of clinical routine inclusion criteria for 3. substudy. - patients receiving a new bivalent (wuhan/omicron ba.1) mrna sars-cov-2 vaccine in the frame of clinical routine, according to the treating physician

inclusion criteria: all patients registered with informed consent from participating cohorts aged ≥18 years additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. covid-19 vaccination recommended by treating physician inclusion criteria for 2. sub protocol (observational study): third covid-19 vaccination recommended by treating physician and administered in the frame of clinical routine

inclusion criteria: all patients registered with informed consent from participating cohorts aged ≥18 years additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. covid-19 vaccination recommended by treating physician inclusion criteria for 2. sub protocol (observational study): third covid-19 vaccination recommended by treating physician and administered in the frame of clinical routine

inclusion criteria: - all patients registered with informed consent from participating cohorts aged ≥18 years - additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: - all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years - patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. - covid-19 vaccination recommended by treating physician

inclusion criteria: - all patients registered with informed consent from participating cohorts aged ≥18 years - additional consent for participation in the specific sub-protocol trial inclusion criteria for pilot trial: - all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years - patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less. - covid-19 vaccination recommended by treating physician

inclusion criteria: - all patients registered with informed consent from participating cohorts aged ≥18 years - additional consent for participation in the pilot trial inclusion criteria for pilot trial: - all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years - patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less.

inclusion criteria: - all patients registered with informed consent from participating cohorts aged ≥18 years - additional consent for participation in the pilot trial inclusion criteria for pilot trial: - all patients with either a chronic hiv infection or recipients of solid organs registered with informed consent from the shcs and stcs cohorts aged ≥18 years - patients with solid organ transplantation of lungs or kidneys at least one month post-transplantation with a prednisone dose of 20mg or less.