inclusion criteria: 1. recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. 2. fulfilling one of the following criteria associated with high risk of clinical deterioration: age 65 years or above, radiological evidence of pneumonia, oxygen desaturation \<94% on room air, comorbidity including hypertension, diabetes, cardiovascular diseases, chronic obstructive lung disease, chronic liver diseases, chronic kidney diseases, malignancy, haematological diseases, rheumatological diseases, immunocompromised hosts and obesity (bmi \> 30) 3. all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. 4. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: 1. recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. 2. fulfilling one of the following criteria associated with high risk of clinical deterioration: age 65 years or above, radiological evidence of pneumonia, oxygen desaturation \<94% on room air, comorbidity including hypertension, diabetes, cardiovascular diseases, chronic obstructive lung disease, chronic liver diseases, chronic kidney diseases, malignancy, haematological diseases, rheumatological diseases, immunocompromised hosts and obesity (bmi \> 30) 3. all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. 4. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. fulfilling one of the following criteria associated with high risk of clinical deterioration: age 65 years or above, radiological evidence of pneumonia, oxygen desaturation <94% on room air, comorbidity including hypertension, diabetes, cardiovascular diseases, chronic obstructive lung disease, chronic liver diseases, chronic kidney diseases, malignancy, haematological diseases, rheumatological diseases, immunocompromised hosts and obesity (bmi > 30) all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. fulfilling one of the following criteria associated with high risk of clinical deterioration: age 65 years or above, radiological evidence of pneumonia, oxygen desaturation <94% on room air, comorbidity including hypertension, diabetes, cardiovascular diseases, chronic obstructive lung disease, chronic liver diseases, chronic kidney diseases, malignancy, haematological diseases, rheumatological diseases, immunocompromised hosts and obesity (bmi > 30) all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: 1. recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. 2. fulfilling one of the following criteria associated with high risk of clinical deterioration: age 65 years or above, radiological evidence of pneumonia, oxygen desaturation <94% on room air, comorbidity including hypertension, diabetes, cardiovascular diseases, chronic obstructive lung disease, chronic liver diseases, chronic kidney diseases, malignancy, haematological diseases, rheumatological diseases, immunocompromised hosts and obesity (bmi > 30) 3. all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. 4. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: 1. recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. 2. fulfilling one of the following criteria associated with high risk of clinical deterioration: age 65 years or above, radiological evidence of pneumonia, oxygen desaturation <94% on room air, comorbidity including hypertension, diabetes, cardiovascular diseases, chronic obstructive lung disease, chronic liver diseases, chronic kidney diseases, malignancy, haematological diseases, rheumatological diseases, immunocompromised hosts and obesity (bmi > 30) 3. all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. 4. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: 1. recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. 2. oxygen desaturation <94% on room air. 3. all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. 4. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.

inclusion criteria: 1. recruited subjects include all adult patients ≥18 years hospitalized for virologic confirmed sars-cov-2 infection. 2. oxygen desaturation <94% on room air. 3. all subjects give written informed consent. for patients who are critically ill, requiring icu, ventilation or confused, informed consent will be obtained from spouse, next-of-kin or legal guardians. 4. subjects must be available to complete the study and comply with study procedures. willingness to allow for serum samples to be stored beyond the study period, for potential additional future testing to better characterize immune response.