Clinical Outcome: COVID-19 burden of diseases (BOD);Duration of RCT set up (specific endpoint related to trial conduct feasibility);immunological outcome: change in anti-Nucleocapsid (N) response;immunological outcome: change in pan-Ig antibody response (pan-Ig anti-S1-RBD);immunological outcome: change in SARS-CoV-2-binding antibodies;Number of participants with newly PCR-confirmed symptomatic COVID-19 infection;Number of participants with newly polymerase chain reaction (PCR)-confirmed asymptomatic COVID-19 infection;Number of participants with severe COVID-19 infection;Patient consent rate;Proportion of missing data for all baseline variables from routinely collected cohort data;Proportion of missing data for all clinical outcomes;SARS-CoV-2-specific antibodies;SARS-CoV-2-specific titers;The proportion of patients with a positive antibody response to SARS-CoV-2 spike (S1) protein receptor binding domain in human serum or plasma assessed in the observational second sub- protocol;Time of patient recruitment from activation of first study site until 380 patients are randomised;Time of patient recruitment from activation of first study site until 40 patients are randomised

Clinical Outcome: COVID-19 burden of diseases (BOD);Duration of RCT set up (specific endpoint related to trial conduct feasibility);immunological outcome: change in anti-Nucleocapsid (N) response;immunological outcome: change in pan-Ig antibody response (pan-Ig anti-S1-RBD);immunological outcome: change in SARS-CoV-2-binding antibodies;Number of participants with newly PCR-confirmed symptomatic COVID-19 infection;Number of participants with newly polymerase chain reaction (PCR)-confirmed asymptomatic COVID-19 infection;Number of participants with severe COVID-19 infection;Patient consent rate;Proportion of missing data for all baseline variables from routinely collected cohort data;Proportion of missing data for all clinical outcomes;SARS-CoV-2-specific antibodies;SARS-CoV-2-specific titers;The proportion of patients with a positive antibody response to SARS-CoV-2 spike (S1) protein receptor binding domain in human serum or plasma assessed in the observational second sub- protocol;Time of patient recruitment from activation of first study site until 380 patients are randomised;Time of patient recruitment from activation of first study site until 40 patients are randomised

Clinical Outcome: COVID-19 burden of diseases (BOD);Duration of RCT set up (specific endpoint related to trial conduct feasibility);immunological outcome: change in anti-Nucleocapsid (N) response;immunological outcome: change in pan-Ig antibody response (pan-Ig anti-S1-RBD);immunological outcome: change in SARS-CoV-2-binding antibodies;Number of participants with newly PCR-confirmed symptomatic COVID-19 infection;Number of participants with newly polymerase chain reaction (PCR)-confirmed asymptomatic COVID-19 infection;Number of participants with severe COVID-19 infection;Patient consent rate;Proportion of missing data for all baseline variables from routinely collected cohort data;Proportion of missing data for all clinical outcomes;SARS-CoV-2-specific antibodies;SARS-CoV-2-specific titers;Time of patient recruitment from activation of first study site until 380 patients are randomised;Time of patient recruitment from activation of first study site until 40 patients are randomised

Clinical Outcome: COVID-19 burden of diseases (BOD);Duration of RCT set up (specific endpoint related to trial conduct feasibility);immunological outcome: change in anti-Nucleocapsid (N) response;immunological outcome: change in pan-Ig antibody response (pan-Ig anti-S1-RBD);immunological outcome: change in SARS-CoV-2-binding antibodies;Number of participants with newly PCR-confirmed symptomatic COVID-19 infection;Number of participants with newly polymerase chain reaction (PCR)-confirmed asymptomatic COVID-19 infection;Number of participants with severe COVID-19 infection;Patient consent rate;Proportion of missing data for all baseline variables from routinely collected cohort data;Proportion of missing data for all clinical outcomes;SARS-CoV-2-specific antibodies;SARS-CoV-2-specific titers;Time of patient recruitment from activation of first study site until 380 patients are randomised;Time of patient recruitment from activation of first study site until 40 patients are randomised

Clinical Outcome: COVID-19 burden of diseases (BOD);Clinical Outcome: Newly PCR-confirmed symptomatic COVID-19 infection;Clinical Outcome: Newly polymerase chain reaction (PCR)-confirmed asymptomatic COVID-19 infection;Clinical Outcome: Severe COVID-19 infection;Duration of RCT set up (specific endpoint related to trial conduct feasibility);immunological outcome: change in anti-Nucleocapsid (N) response;immunological outcome: change in pan-Ig antibody response (pan-Ig anti-S1-RBD);immunological outcome: change in SARS-CoV-2-binding antibodies;Patient consent rate;Proportion of missing data for all baseline variables from routinely collected cohort data;Proportion of missing data for all clinical outcomes;SARS-CoV-2-specific antibodies;SARS-CoV-2-specific titers;Time of patient recruitment from activation of first study site until 380 patients are randomised;Time of patient recruitment from activation of first study site until 40 patients are randomised

Clinical Outcome: COVID-19 burden of diseases (BOD);Clinical Outcome: Newly PCR-confirmed symptomatic COVID-19 infection;Clinical Outcome: Newly polymerase chain reaction (PCR)-confirmed asymptomatic COVID-19 infection;Clinical Outcome: Severe COVID-19 infection;Duration of RCT set up (specific endpoint related to trial conduct feasibility);immunological outcome: change in anti-Nucleocapsid (N) response;immunological outcome: change in pan-Ig antibody response (pan-Ig anti-S1-RBD);immunological outcome: change in SARS-CoV-2-binding antibodies;Patient consent rate;Proportion of missing data for all baseline variables from routinely collected cohort data;Proportion of missing data for all clinical outcomes;SARS-CoV-2-specific antibodies;SARS-CoV-2-specific titers;Time of patient recruitment from activation of first study site until 380 patients are randomised;Time of patient recruitment from activation of first study site until 40 patients are randomised