Evaluating Safety and Immune Response to the HIV-1 CH505 Transmitted/Founder gp120 Adjuvanted With GLA-SE in Healthy, HIV-exposed Uninfected Infants

At each study visit, the infant's weight was measured. Using weight and age, a WHO weight-for-age z-score will be calculated using the World Health Organization (WHO) anthropometric calculator tool. Weight-for-age reflects body weight relative to the child's age on a given day. A Z-score of 0 represents the population mean, a Z-score less than -2 indicates an infant who is underweight, -2 to 2 indicates an infant who is normal weight, and above 2 indicates the infant may have a growth problem, but this is better assessed from weight-for-length.

This Outcome Measure was not collected for Mothers.

At each study visit, the infant's weight was measured. Using weight and age, a WHO weight-for-age z-score was calculated using the World Health Organization (WHO) anthropometric calculator tool. Weight-for-age reflects body weight relative to the child's age on a given day. Z-scores less than -2 indicates an infant who is underweight, -2 to 2 indicates an infant who is normal weight, and above 2 indicates the infant may have a growth problem, but this is better assessed from weight-for-length.

At each study visit, the infant's length and weight was measured. Using these measurements, a WHO weight-for-length z-score was calculated using the World Health Organization (WHO) anthropometric calculator tool. Weight-for-length reflects body weight in proportion to attained growth in length. A Z-score of 0 represents the population mean, a Z-score less than -2 indicates an infant who is wasted, -2 to 2 indicates an infant who is normal weight, and above 2 indicates the infant is overweight.

This Outcome Measure was not collected for Mothers.

At each study visit, the infant's length and weight was measured. Using these measurements, a WHO weight-for-length z-score was calculated using the World Health Organization (WHO) anthropometric calculator tool. Weight-for-length reflects body weight in proportion to attained growth in length. Z-scores less than -2 indicates an infant who is wasted, -2 to 2 indicates an infant who is normal weight, and above 2 indicates the infant is overweight.

Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 [July 2017]. The maximum grade observed for each symptom over the time frame is presented.

This Outcome Measure was not collected for Mothers.

Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 [July 2017]. The maximum grade observed for each symptom over the time frame is presented.

This Outcome Measure was not collected for Mothers.

Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 [July 2017]. The following symptoms are considered as systemic reactogenicity if the onset date was within the periods of assessment specified in the protocol: fever, sleepiness/lethargy, rash, vomiting, anorexia, seizure. The item Max. Systemic Symptoms is the maximum of the individual systemic reactogenicities for a participant.

This Outcome Measure was not collected for Mothers.

The number (percentage) of participants with local laboratory values recorded as meeting Grade 1 AE criteria or above as specified in the Division of AIDS Table for Grading the Severity of Adult and Pediatric Adverse Events for alanine aminotransferase (ALT), creatinine, hemoglobin, lymphocyte count, neutrophil count, platelets, white blood cells (WBC) was summarized by treatment arm for each post vaccination time point.

This Outcome Measure was not collected for Mothers.

Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Corrected Version 2.1, July 2017 (exceptions apply).

This Outcome Measure was not collected for Mothers.

Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Corrected Version 2.1, July 2017 (exceptions apply).

This Outcome Measure was not collected for Mothers.

Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Corrected Version 2.1, July 2017 (exceptions apply).

This Outcome Measure was not collected for Mothers.

Serum HIV-1-specific IgG responses were measured on a BioPlex instrument (BioRad) using a standardized custom HIV-1 Luminex assay. The readout was background-subtracted mean fluorescence intensity (MFI), where background referred to a plate level control. Net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. The area under the curve (AUC) was calculated for each participant and antigen using the trapezoidal rule, where the x-axis is log10 dilution and the y-axis is the Net MFI with negative values set to 0. AUC is considered the primary measure of response magnitude.

HIV-1 Env-specific B cells induced by vaccination were identified and characterized using fluorescently labeled recombinant Env proteins in the context of a flow cytometry panel to identify and characterize those B cell. Total B cells are identified using doublet exclusion, lymphocyte scatter profile, a viability dye to exclude dead cells, and are negative for lineage markers: CD3, CD56 and CD14; and positive for CD19 and CD20. B cells are further gated as IgD-, then IgG+, and IgA+.

HIV-1 Env-specific B cells induced by vaccination were identified and characterized using fluorescently labeled recombinant Env proteins in the context of a flow cytometry panel to identify and characterize those B cell. Total B cells are identified using doublet exclusion, lymphocyte scatter profile, a viability dye to exclude dead cells, and are negative for lineage markers: CD3, CD56 and CD14; and positive for CD19 and CD20. B cells are further gated as IgD-, then IgG+, and IgA+.

PVMA uses the same Luminex instrument and techniques as HVTN's standard Binding Antibody Multiplex Assay (BAMA) to assess serum samples for antibodies against diphtheria, tetanus, pertussis, and rubella. The assay is a reliable, high-throughput technique that requires minimal sample volume and measures multiple antibody concentrations. A Hepatitis B antigen was tested as part of the PVMA panel, but did not pass lab-internal QC. The lab opted to test this antigen via ELISA and reported those calculated concentration data for analysis in lieu of the HepB PVMA data. A HepB standard was used in each assay for quality control.

PVMA uses the same Luminex instrument and techniques as HVTN's standard Binding Antibody Multiplex Assay (BAMA) to assess serum samples for antibodies against Haemophilus influenzae type B (HiB) and respiratory syncytial virus (RSV). The assay is a reliable, high-throughput technique that requires minimal sample volume and measures multiple antibody concentrations.

Neutralizing antibodies against tier 1 and tier 2 strains of HIV-1 were measured as a function of reductions in Tat-regulated luciferase (Luc) reporter gene expression in TZM-bl cells. All serum samples were assayed against Tier 1 and Tier 2 strains of virus by starting with a 1:10 dilution of serum to obtain a neutralizing antibody titer. ID50 (ID80) titers are defined as the serum dilution that reduces RLUs by 50% (or 80%) relative to the RLUs in virus control wells after subtraction of background.

Serum HIV-1-specific FcR responses (1:50 dilution) were measured using the standardized custom HIV-1 Luminex assay on a Luminex FLEXMAP 3D system. Readouts were background-subtracted mean fluorescence intensity (MFI), with background defined by plate-level controls. Net MFI was calculated as experimental minus reference antigen MFI, and values <1 were set to 1. Post-enrollment samples were considered positive if they met all three criteria: (1) Net MFI ≥ antigen-specific cutoff (95th percentile of HVTN 115 Part A baseline at Day 0) and ≥ 100 above blank; (2) Net MFI > 3 times the median baseline Net MFI; and (3) MFI > 3 times the median baseline MFI. Response calls were based on the 1:50 dilution. Data were excluded if the blood draw was outside the allowable window, the participant was HIV positive, reference antigen MFI > 5,000, or baseline net MFI > 6,500.

Serum HIV-1-specific FcR (dilution 1:50) responses were measured on a Luminex FLEXMAP 3D Instrument System using a standardized custom HIV-1 Luminex assay. The readout was background-subtracted mean fluorescence intensity (MFI), where background referred to a plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Net MFI less than 1 is set to 1. Data are excluded if blood draw date was outside the allowable window, a participant was HIV-infected, reference antigen > 5,000 MFI, or baseline net MFI > 6,500.

The qualified GranToxiLux Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC-GTL) assay was performed to measure ADCC-mediated antibody responses. ADCC is quantified as net percent granzyme B activity, which is the percent of target cells positive for GTL (an indicator of granzyme B uptake) minus the percent of target cells positive for GTL when incubated with effector cells in the absence of a source of antibodies. Flow cytometry is used to quantify the frequency of granzyme B positive cells. There is no baseline subtraction applied to the responses, and a fixed positivity threshold is applied to %GzB activity. A positive response is defined as ≥ 8% GzB activity.

The qualified GranToxiLux Antibody-Dependent Cell-Mediated Cytotoxicity (ADCC-GTL) assay was performed to measure ADCC-mediated antibody responses. ADCC is quantified as net percent granzyme B activity, which is the percent of target cells positive for GTL (an indicator of granzyme B uptake) minus the percent of target cells positive for GTL when incubated with effector cells in the absence of a source of antibodies. Flow cytometry is used to quantify the frequency of granzyme B positive cells.

ADCC-mediated antibody responses were measured by luciferase ADCC assay using HIV CH0505s.LucR.T2A.ecto/293T/17 Infectious Molecular Clone (IMC)-infected target cells. Luminescence intensity reflects the number of intact target cells remaining after incubation with effector cells in the presence or absence of ADCC-mediating serum antibodies. Lower luminescence corresponds to fewer intact target cells. The outcome measure was calculated as the percent specific change in luciferase activity, defined as: percent specific change in luciferase activity = 100 * (RLU of target and effector well- RLU of test well)/(RLU of target and effector well). There is no baseline subtraction applied to the responses, and a fixed positivity threshold is applied to percent killing or loss of luciferase activity. A positive response is defined as percent specific killing ≥ 15%.

ADCC-mediated antibody responses were measured by luciferase ADCC assay using HIV CH0505s.LucR.T2A.ecto/293T/17 Infectious Molecular Clone (IMC)-infected target cells. Luminescence intensity reflects the number of intact target cells remaining after incubation with effector cells in the presence or absence of ADCC-mediating serum antibodies. Lower luminescence corresponds to fewer intact target cells. The outcome measure was calculated as the percent specific change in luciferase activity, defined as: percent specific change in luciferase activity = 100 * (RLU of target and effector well- RLU of test well)/(RLU of target and effector well).

ADCP assay is a qualified assay employing flow cytrometric-based technology that measures the ability of antibodies to mediate phagocytosis. A phagocytic score is determined based on the ratio of experimental sample to PBS control. Mean phagocytosis score is defined as: (% bead positive for participant x MFI bead positive for participant) / (% bead positive for PBS only control x MFI bead positive for PBS only control). Higher phagocytosis score values indicate a greater level of antibody-mediated phagocytic activity relative to the PBS control, while values closer to 1 indicate minimal activity above background. Positivity calls were based on two criteria: 1) Average ADCP score ≥ antigen specific cutoff values (max(95th percentile of HVTN 115 baseline ADCP score, 1)) and 2) Average ADCP score > 3x antigen specific median HVTN 115 baseline average ADCP score.

ADCP assay is a qualified assay employing flow cytrometric-based technology that measures the ability of antibodies to mediate phagocytosis. A phagocytic score is determined based on the ratio of experimental sample to PBS control. Mean phagocytosis score is defined as: (% bead positive for participant x MFI bead positive for participant) / (% bead positive for PBS only control x MFI bead positive for PBS only control). Higher phagocytosis score values indicate a greater level of antibody-mediated phagocytic activity relative to the PBS control, while values closer to 1 indicate minimal activity above background.