Characterizing SARS-CoV-2-specific Immunity in Individuals Who Have Recovered From COVID-19

Study at a glance

From the registry record, last updated by the sponsor on 12 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.

Official title

Characterizing SARS-CoV-2-specific Immunity in Convalescent Individuals

ClinicalTrials.gov ID

NCT04403880

Acronym / sponsor ID

HVTN 405/HPTN 1901

Conditions

SARS-CoV-2, COVID-19

Study type

Observational

Recruitment status

Completed

Enrolment

760 participants (actual)

Lead sponsor

HIV Vaccine Trials NetworkResearch network

Collaborators

National Institute of Allergy and Infectious Diseases (NIAID), HIV Prevention Trials Network

Study start

13 May 2020 (actual)

Primary completion

21 Apr 2022 (actual)

Study completion

21 Apr 2022 (actual)

First posted

27 May 2020 (actual)

Results

Posted 12 Jan 2026

Clinical summary

The research question as the sponsor registered it. This describes what the study plans to test, not what it found.

Study design

Observational model

Cohort

Time perspective

Other

Number of arms

3

Who may qualify

Ages

18 years and older

Sex

All

Healthy volunteers

Accepted

Age groups

Adult, Older adult

Study population

Persons reporting a positive test for SARS-CoV-2 and resolution of COVID-19 within 1-8 weeks of enrollment OR, if asymptomatic infection, reporting positive SARS-CoV-2 test within 2-10 weeks of enrollment.

Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.

Interventions

Primary outcome

1. SARS-CoV-2-specific Antibody Binding Response Rate (BAMA IgG1) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2, 4

   BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3, overall and by region and enrollment group

2. SARS-CoV-2-specific Antibody Binding Response Magnitude (BAMA IgG1) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2, 4

   BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3, overall and by region and enrollment group

3. SARS-CoV-2-specific Antibody Binding Response Rate (BAMA IgG3) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2

   BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarizedSARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and enrollment group among America Cohort

4. SARS-CoV-2-specific Antibody Binding Response Magnitude (BAMA IgG3) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2

   BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarizedSARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and enrollment group among America Cohort

5. SARS-CoV-2-specific Antibody Binding Response Rate (BAMA IgA) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2

   BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and enrollment group among America Cohort

6. SARS-CoV-2-specific Antibody Binding Response Magnitude (BAMA IgA) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2

   BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and enrollment group among America Cohort

7. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2, 4, 12

   Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and enrollment group among America Cohort (USA and Peru only)

8. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and Enrollment Group Among America Cohort

   Time frame: Measured at Months 0, 2, 4, 12

   Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2,3,4, overall and by region and enrollment group among America Cohort (USA and Peru only)

9. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and Enrollment Group Among Africa Cohort

   Time frame: Measured at Months 0, 2, 4, 12

   Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and enrollment group among Africa Cohort

10. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and Enrollment Group Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and enrollment group among Africa Cohort

11. SARS-CoV-2-specific Antibody Binding Response Rate (ADCC) by Region and Enrollment Group Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by antibody-dependent cellular cytotoxicity assay (ADCC) at Visit 1, overall and by region and enrollment group among America Cohort (USA and Peru only)

12. SARS-CoV-2-specific Antibody Binding Response Magnitude (ADCC) by Region and Enrollment Group Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by antibody-dependent cellular cytotoxicity assay (ADCC) Visit 1, overall and by region and enrollment group among America Cohort

13. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate (ICS) by Region and Enrollment Group Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate by flow cytometry at Visit 1 , overall and by region and enrollment group among America Cohort (USA and Peru only)

14. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude (ICS) by Region and Enrollment Group Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and enrollment group among America Cohort positive responders (USA and Peru)

15. SARS-CoV-2-specific Memory B Cell Response Magnitude (B Cell) by Region and Enrollment Group Among America Cohort

    Time frame: Measured at Months 0.

    SARS-CoV-2-specific B cell responses and B cell phenotypic data was identified and characterized using fluorescently-labelled recombinant Env proteins (S6P and RBD) in combination with a flow cytometry antibody panel on all available samples from the enrollment visit (V1). There is no positivity call for B cell phenotypic data. The magnitude is B cell subset frequency. The table summarized SARS-CoV-2-specific Memory B Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and enrollment group among America Cohort (USA and Peru only)

16. SARS-CoV-2-specific Antibody Binding Response Rate (IgG1) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2, 4

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3 , overall and by region and COVID-19 severity among America Cohort (USA and Peru)

17. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgG1) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2, 4

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

18. SARS-CoV-2-specific Antibody Binding Response Rate (IgG3) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

19. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgG3) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point.SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

20. SARS-CoV-2-specific Antibody Binding Response Rate (IgA) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

21. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgA) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

22. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and COVID-19 severity

23. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2,3,4, overall and by region and COVID-19 severity among America Cohort

24. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and COVID-19 Severity Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and COVID-19 severity

25. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and COVID-19 Severity Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and COVID-19 severity among Africa Cohort

26. SARS-CoV-2-specific Antibody Binding Response Rate (ADCC) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by antibody-dependent cellular cytotoxicity assay (ADCC) at Visit 1, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

27. SARS-CoV-2-specific Antibody Binding Response Magnitude (ADCC) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by antibody-dependent cellular cytotoxicity assay (ADCC) Visit 1, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

28. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate (ICS) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate by flow cytometry at Visit 1, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

29. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude (ICS) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and COVID-19 severity among America Cohort

30. SARS-CoV-2-specific Memory B Cell Response Magnitude (B Cell) by Region and COVID-19 Severity Among America Cohort

    Time frame: Measured at Months 0

    SARS-CoV-2-specific B cell responses and B cell phenotypic data was identified and characterized using fluorescently-labelled recombinant Env proteins (S6P and RBD) in combination with a flow cytometry antibody panel on all available samples from the enrollment visit (V1). The sample will be included in the analysis only if the number of IgD- B cells is equal or greater than 1000 for that sample. The table summarized SARS-CoV-2-specific Memory B Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and COVID-19 severity among America Cohort (USA and Peru)

31. SARS-CoV-2-specific Antibody Binding Response Rate (IgG1) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

32. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgG1) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by BAMA IgG1 at Visit 1, 2, 3, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

33. SARS-CoV-2-specific Antibody Binding Response Rate (IgG3) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

34. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgG3) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

35. SARS-CoV-2-specific Antibody Binding Response Rate (IgA) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

36. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgA) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

37. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

38. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2,3, 4, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

39. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and Days Since SARS-CoV-2 Diagnosis Group Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and days since SARS-CoV-2 diagnosis group among Africa Cohort

40. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and Days Since SARS-CoV-2 Diagnosis Group Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and days since SARS-CoV-2 diagnosis group among Africa Cohort

41. SARS-CoV-2-specific Antibody Binding Response Rate (ADCC) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by antibody-dependent cellular cytotoxicity assay (ADCC) at Visit 1, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort (USA and Peru)

42. SARS-CoV-2-specific Antibody Binding Response Magnitude (ADCC) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by antibody-dependent cellular cytotoxicity assay (ADCC) Visit 1, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

43. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate (ICS) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate by flow cytometry at Visit 1, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

44. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude (ICS) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and days since SARS-CoV-2 diagnosis group among America Cohort

45. SARS-CoV-2-specific Memory B Cell Response Magnitude (B Cell) by Region and Days Since SARS-CoV-2 Diagnosis Group Among America Cohort

    Time frame: Measured at Months 0

    SARS-CoV-2-specific B cell responses and B cell phenotypic data was identified and characterized using fluorescently-labelled recombinant Env proteins (S6P and RBD) in combination with a flow cytometry antibody panel on all available samples from the enrollment visit (V1). The sample will be included in the analysis only if the number of IgD- B cells is equal or greater than 1000 for that sample. The table summarized SARS-CoV-2-specific Memory B Cell Response Magnitude (B Cell) by Region and Days Since SARS-CoV-2 Diagnosis Group among America Cohort

46. SARS-CoV-2-specific Antibody Binding Response Rate (IgG1) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3 , overall and by region and comorbidity group among America Cohort

47. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgG1) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG1) at Visit 1, 2, 3, overall and by region and comorbidity group among America Cohort

48. SARS-CoV-2-specific Antibody Binding Response Rate (IgG3) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and comorbidity group among America Cohort

49. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgG3) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgG3) at Visit 1, 2, overall and by region and comorbidity group among America Cohort

50. SARS-CoV-2-specific Antibody Binding Response Rate (IgA) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and comorbidity group among America Cohort

51. SARS-CoV-2-specific Antibody Binding Response Magnitude (IgA) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2

    BAMA assays was performed for samples from participants at Visit 1 (Month 0, baseline) and available samples at follow-up visits (Month 2, 4). Serum SARS-CoV-2-specific IgA, IgG1, IgG3 responses (dilution 1:50) to SARS-CoV-2 antigens were measured on a Bio-Plex instrument (Bio-Rad). The Bioplex software provides 2 readouts: a background-subtracted mean fluorescence intensity (MFI), where background refers to a plate level control (i.e., a blank well run on each plate), and a concentration based on a standard curve. Positive responses at each visit will be called if the MFI minus blank values are ≥ isotype, antigen, and dilution-specific cutoff (will be provided by the lab). MFIs minus blank (or net MFI) are used to summarize the magnitude at a given time-point. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by binding antibody multiplex assay (BAMA IgA) at Visit 1, 2, overall and by region and comorbidity group among America Cohort

52. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and comorbidity group among America Cohort

53. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2,3,4, overall and by region and comorbidity group among America Cohort

54. SARS-CoV-2-specific Antibody Binding Response Rate (Nab) by Region and Comorbidity Group Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and comorbidity group among Africa Cohort

55. SARS-CoV-2-specific Antibody Binding Response Magnitude (Nab) by Region and Comorbidity Group Among Africa Cohort

    Time frame: Measured at Months 0, 2, 4, 12

    Neutralizing antibodies against SARS coronaviruses are measured in 293T/ACE2 cells for all HIV negative samples. MPI (maximum percent inhibition) is also measured. Positivity calls are an ID50/ID80 (50% and 80% inhibitory dose) value either >20 (the lower limit of detection (LLOD) of the assay) or MPI is between 10%-50%. The neutralizing antibody ID50/ID80 of all HIV positive samples are measured by a different assay, VSV pseudovirus neutralization assay. Positivity calls are based on whether or not any neutralization is observed through entire titration (starting dilution 1:20) with MPI between 10%-50%. For the positive calls but the neutralization does not reach 50% or 80%, ID50/ID80 titer is first estimated by Prism. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by neutralizing antibody assay (NAb) at Visit 1, 2, 3, 4, overall and by region and comorbidity group among Africa Cohort

56. SARS-CoV-2-specific Antibody Binding Response Rate (ADCC) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Rate by antibody-dependent cellular cytotoxicity assay (ADCC) at Visit 1, overall and by region and comorbidity group among America Cohort

57. SARS-CoV-2-specific Antibody Binding Response Magnitude (ADCC) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0

    Antibody-dependent NK cell degranulation will be measured using ADCC assay at a dilution 1:500. Two readouts will be the background-subtracted % CD107A+ NK cells for the infected cells and the background-subtracted % CD107A+ NK cells for the transfected cells. The positive responses will be called if the values of background-subtracted % CD107A+ ≥ 4.07 and ≥5.27 for the infected and transfected cells, respectively. The cutoffs are determined by mean+2SD, respectively, from the SARS-CoV-2 negative controls. Percent CD107a+ NK Cells was the response magnitudes. The table summarized SARS-CoV-2-specific Antibody Binding Response Magnitude by antibody-dependent cellular cytotoxicity assay (ADCC) Visit 1, overall and by region and comorbidity group among America Cohort

58. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate (ICS) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Rate by flow cytometry at Visit 1, overall and by region and comorbidity group among America Cohort

59. SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude (ICS) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0

    Flow cytometry was used to examine SARS-CoV-2 specific CD4+ and CD8+ T-cell responses using an intracellular cytokine staining (ICS). Positive calls will be made using Fisher's exact positivity test for all the markers. The magnitudes are % T cells expressing IFN-g/IL-2. The table summarized SARS-CoV-2-specific CD4+ and CD8+ T Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and Comorbidity Group among America Cohort

60. SARS-CoV-2-specific Memory B Cell Response Magnitude (B Cell) by Region and Comorbidity Group Among America Cohort

    Time frame: Measured at Months 0

    SARS-CoV-2-specific B cell responses and B cell phenotypic data was identified and characterized using fluorescently-labelled recombinant Env proteins (S6P and RBD) in combination with a flow cytometry antibody panel on all available samples from the enrollment visit (V1). The sample will be included in the analysis only if the number of IgD- B cells is equal or greater than 1000 for that sample. The table summarized SARS-CoV-2-specific Memory B Cell Response Magnitude by flow cytometry at Visit 1, overall and by region and comorbidity group among America Cohort

61. SARS-CoV-2-specific Infection Presentation, Including Clinical Course, Along With Demographics and Corresponding Medical History of Participants , Overall and by Region Among America Cohort

    Time frame: Measured at Months 0

    SARS-CoV-2-specific Infection Presentation, Including Clinical Course, Along With Demographics and Corresponding Medical History of Participants , overall and by region

62. SARS-CoV-2-specific Infection Presentation, Including Clinical Course, Along With Demographics and Corresponding Medical History of Participants , Overall and by Region Among Africa Cohort

    Time frame: Measured at Months 0

    SARS-CoV-2-specific Infection Presentation, Including Clinical Course, Along With Demographics and Corresponding Medical History of Participants , overall and by region

Results and safety

Loading the posted results from ClinicalTrials.gov…

Research links

• Official record on ClinicalTrials.govLast updated by the sponsor 12 Jan 2026.
• Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
• Derived from this study: PubMed 37352144Karuna S, Gallardo-Cartagena JA, Theodore D, Hunidzarira P, Montenegro-Idrogo J, Hu J, Jones M, Kim V, De La Grecca R, Trahey M, Karg C, Takalani A, Polakowski L, Hutter J, Miner MD, Erdmann N, Goepfert P, Maboa R, Corey L, Gill K, Li SS; HVTN 405/HPTN 1901 Study Team. Post-COVID symptom profiles and duration in a global convalescent COVID-19 observational cohort: Correlations with demographics, medical history, acute COVID-19 severity and global region. J Glob Health. 2023 Jun 23;13:06020. doi: 10.7189/jogh.13.06020.
• Derived from this study: PubMed 34871308Karuna S, Li SS, Grant S, Walsh SR, Frank I, Casapia M, Trahey M, Hyrien O, Fisher L, Miner MD, Randhawa AK, Polakowski L, Kublin JG, Corey L, Montefiori D; HVTN 405/HPTN 1901 Study Team. Neutralizing antibody responses over time in demographically and clinically diverse individuals recovered from SARS-CoV-2 infection in the United States and Peru: A cohort study. PLoS Med. 2021 Dec 6;18(12):e1003868. doi: 10.1371/journal.pmed.1003868. eCollection 2021 Dec.

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  SARS-CoV-2

• RecruitingObservational study

  Viral Infections in Healthy and Immunocompromised Hosts

  Anogenital Herpes, COVID-19

• Not yet recruitingPhase 1

  Phase I Open-Label Safety Trial of Pembrolizumab for Neurological Post- Acute Sequelae of SARS-CoV-2 (PD1-PASC I)

  Post-Acute COVID-19 Syndrome

• RecruitingPhase 2

  COVID-19 Booster and IIV Schedule in Immunocompromised Hosts

  COVID 19, Influenza

• Enrolling by invitationPhase 2

  Immunotherapy for Neurological Post-Acute Sequelae of SARS-CoV-2

  Systemic Inflammation, Neuroinflammation

Referral and contact

AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.

53 sites in 6 countries: see every site and its status.