Evaluating the Safety and Immunogenicity of ALVAC-HIV and MF59®- or AS01B-adjuvanted Bivalent Subtype C gp120 in Healthy, HIV-uninfected Adult Participants

HIV Infections Clinical Trial

— HVTN 120  

Official title:

A Phase 1/2a Clinical Trial to Evaluate the Safety and Immunogenicity of ALVAC-HIV (vCP2438) and of MF59®- or AS01B-adjuvanted Clade C Env Protein, in Healthy, HIV-uninfected Adult Participants

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03122223
• Other study ID #: HVTN 120
• Secondary ID: 36128
• Status: Completed
• Phase: Phase 1/Phase 2
• Start date: January 16, 2018
• Est. completion date: July 30, 2020

Study information

• Verified date: March 2023
• Source: National Institute of Allergy and Infectious Diseases (NIAID)
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

A phase 1/2a clinical trial to evaluate the safety and immunogenicity of ALVAC-HIV (vCP2438) and of MF59®- or AS01B-adjuvanted clade C Env protein, in healthy, HIV-uninfected adult participants

Description:

The primary objective of this study is to evaluate the safety and tolerability of ALVAC-HIV and bivalent gp120 protein/MF59 or bivalent gp120 protein/AS01(B). This study will also compare HIV-specific CD4+ T-cell response rates at the Month 6.5 timepoint (2 weeks after the fourth vaccination) of ALVAC-HIV and bivalent gp120 protein/MF59 to each of the bivalent gp120 protein/AS01(B) vaccine regimens. Additionally, this study will compare HIV-specific Env-gp120 binding antibody response magnitudes at the Month 12 timepoint (6 months after the fourth vaccination) of ALVAC-HIV and bivalent gp120 protein/MF59 to each of the bivalent gp120 protein/AS01(B) vaccine regimens.

The study will enroll 160 healthy, HIV-uninfected volunteers aged 18 to 40 years. Groups 1 to 3 will consist of a total of 150 participants who will receive the vaccines at Months 0, 1, 3, and 6, while 10 participants in Group 4 will receive placebos at Months 0, 1, 3, 6.

Study visits will include a physical examination, an interview and/or questionnaire, HIV testing and HIV risk-reduction counseling, and urine and blood collection. Participants may optionally choose to provide rectal fluid, cervical fluid, semen, and/or stool samples.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 160
• Est. completion date: July 30, 2020
• Est. primary completion date: July 30, 2020
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 40 Years

Eligibility

Inclusion Criteria:

General and Demographic Criteria:

• Age of 18 to 40 years

• Access to a participating HVTN clinical research site (CRS) and willingness to be followed for the planned duration of the study

• Ability and willingness to provide informed consent

• Assessment of understanding: volunteer demonstrates understanding of this study; provides answers to a questionnaire prior to first vaccination with verbal demonstration of understanding of all questionnaire items answered incorrectly

• Agrees not to enroll in another study of an investigational research agent before the last required clinic visit

• Good general health as shown by medical history, physical exam, and screening laboratory tests

HIV-Related Criteria:

• Willingness to receive HIV test results

• Willingness to discuss HIV infection risks and amenable to HIV risk reduction counseling

• Assessed by the clinic staff as being at "low risk" for HIV infection and committed to maintaining behavior consistent with low risk of HIV exposure through the last required protocol clinic visit (see the study protocol for more information about low risk guidelines).

Laboratory Inclusion Values:

Hemogram/Complete Blood Count (CBC):

• Hemoglobin greater than or equal to 11.0 g/dL for volunteers who were assigned female sex at birth, greater than or equal to 13.0 g/dL for volunteers who were assigned male sex at birth. For transgender participants who have been on hormone therapy for more than 6 consecutive months, determine hemoglobin eligibility based on the gender with which they identify (ie, a transgender female who has been on hormone therapy for more than 6 consecutive months should be assessed for eligibility using the hemoglobin parameters for persons assigned female sex at birth).

• White blood cell count equal to 3,300 to 12,000 cells/mm^3

• Total lymphocyte count greater than or equal to 800 cells/mm^3

• Remaining differential either within institutional normal range or with site physician approval

• Platelets equal to 125,000 to 550,000/mm^3

Chemistry:

• Chemistry panel: ALT, AST, and ALP less than 1.25 times the institutional upper limit of normal; creatinine less than or equal to institutional upper limit of normal.

Virology:

• Negative HIV-1 and -2 blood test: US volunteers must have a negative FDA-approved enzyme immunoassay (EIA). Non-US sites may use locally available assays that have been approved by HVTN Laboratory Operations.

• Negative Hepatitis B surface antigen (HBsAg)

• Negative anti-Hepatitis C virus antibodies (anti-HCV), or negative HCV polymerase chain reaction (PCR) if the anti-HCV is positive

Urine:

• Normal urine:

• Negative urine glucose, and

• Negative or trace urine protein, and

• Negative or trace urine hemoglobin (if trace hemoglobin is present on dipstick, a microscopic urinalysis with red blood cells levels within institutional normal range).

Reproductive Status:

• Volunteers who were assigned female sex at birth: negative serum or urine beta human chorionic gonadotropin pregnancy test performed prior to vaccination on the day of initial vaccination. Persons who are NOT of reproductive potential due to having undergone total hysterectomy or bilateral oophorectomy (verified by medical records), are not required to undergo pregnancy testing.

• Reproductive status: Africa - A volunteer who was assigned female sex at birth must:

• Agree to consistently use effective contraception (see the study protocol for more information) for sexual activity that could lead to pregnancy from at least 21 days prior to enrollment through the last required protocol clinic visit. Effective contraception for participants in Africa is defined as using 2 methods of birth control. These include 1 of the following methods:

• Condoms (male or female), or

• Diaphragm or cervical cap, PLUS 1 of the following methods:

• Intrauterine device (IUD),

• Hormonal contraception (in accordance with applicable national contraception guidelines),

• Successful vasectomy in any partner assigned male at birth (considered successful if a volunteer reports that a male partner has [1] documentation of azoospermia by microscopy, or [2] a vasectomy more than 2 years ago with no resultant pregnancy despite sexual activity after vasectomy); or

• Any other contraceptive method approved by the HVTN 120 Protocol Safety Review Team (PSRT)

• Or not be of reproductive potential, such as having reached menopause (no menses for 1 year) or having undergone hysterectomy, bilateral oophorectomy, or tubal ligation;

• Or be sexually abstinent.

• Reproductive status: United States - A volunteer who was assigned female sex at birth must:

• Agree to consistently use effective contraception (see the study protocol for more information) for sexual activity that could lead to pregnancy from at least 21 days prior to enrollment through the last required protocol clinic visit. Effective contraception for participants in the United States is defined as using any 1 or more of the following methods of birth control:

• Condoms (male or female) with or without spermicide,

• Diaphragm or cervical cap with spermicide,

• Intrauterine device (IUD),

• Hormonal contraception, or

• Successful vasectomy in any partner assigned male at birth (considered successful if a volunteer reports that a male partner has [1] documentation of azoospermia by microscopy, or [2] a vasectomy more than 2 years ago with no resultant pregnancy despite sexual activity after vasectomy); or

• Any other contraceptive method approved by the HVTN 120 PSRT

• Or must not be of reproductive potential, such as having reached menopause (no menses for 1 year) or having undergone hysterectomy, bilateral oophorectomy, or tubal ligation;

• Or must be sexually abstinent.

• Volunteers who were assigned female sex at birth must also agree not to seek pregnancy through alternative methods, such as artificial insemination or in vitro fertilization until after the last required protocol clinic visit

Other:

• Volunteers 21 years of age and older who were assigned female sex at birth consenting to provide cervical samples:

• Pap smear within:

• the 3 years prior to enrollment with the latest result reported as normal or ASCUS (atypical squamous cells of undetermined significance), OR

• the 5 years prior to enrollment, with the latest result reported as normal, or ASCUS with no evidence of high risk HPV.

• If no pap smear was done within the last 3 years prior to enrollment (or within the last 5 years, if high risk HPV testing was performed), the volunteer must be willing to undergo a pap smear with the result reported as normal or ASCUS prior to sample collection.

Exclusion Criteria:

General:

• Blood products received within 120 days before first vaccination

• Investigational research agents received within 30 days before first vaccination

• Body mass index (BMI) greater than or equal to 40; or BMI greater than or equal to 35 with 2 or more of the following: systolic blood pressure greater than 140 mm Hg, diastolic blood pressure greater than 90 mm Hg, current smoker, known hyperlipidemia

• Intent to participate in another study of an investigational research agent or any other study that requires non-HVTN HIV antibody testing during the planned duration of the HVTN 120 study

• Pregnant or breastfeeding

• Active duty and reserve U.S. military personnel

Vaccines and Other Injections:

• HIV vaccine(s) received in a prior HIV vaccine trial. For volunteers who have received control/placebo in an HIV vaccine trial, the HVTN 120 PSRT will determine eligibility on a case-by-case basis.

• Previous receipt of monoclonal antibodies (mAbs), whether licensed or investigational; the HVTN 120 PSRT will determine eligibility on a case-by-case basis.

• Non-HIV experimental vaccine(s) received within the last 5 years in a prior vaccine trial. Exceptions may be made for vaccines that have subsequently undergone licensure. For volunteers who have received control/placebo in an experimental vaccine trial, the HVTN 120 PSRT will determine eligibility on a case-by-case basis. For volunteers who have received an experimental vaccine(s) more than 5 years ago, eligibility for enrollment will be determined by the HVTN 120 PSRT on a case-by-case basis.

• Live attenuated vaccines received within 30 days before first study vaccination or scheduled within 14 days after first study vaccination (eg, measles, mumps, and rubella [MMR]; oral polio vaccine [OPV]; varicella; yellow fever; live attenuated influenza vaccine)

• Any vaccines that are not live attenuated vaccines and were received within 14 days prior to first study vaccination (eg, tetanus, pneumococcal, Hepatitis A or B)

• Allergy treatment with antigen injections within 30 days before first study vaccination or that are scheduled within 14 days after first study vaccination

Immune System:

• Immunosuppressive medications received within 168 days before first study vaccination. (Not exclusionary: [1] corticosteroid nasal spray; [2] inhaled corticosteroids; [3] topical corticosteroids for mild, uncomplicated dermatitis; or [4] a single course of oral/parenteral prednisone or equivalent at doses less than or equal to 60 mg/day and length of therapy less than 11 days with completion at least 30 days prior to enrollment.

• Serious adverse reactions to vaccines or to vaccine components such as eggs, egg products, or neomycin, including history of anaphylaxis and related symptoms such as hives, respiratory difficulty, angioedema, and/or abdominal pain. (Not excluded from participation: a volunteer who had a nonanaphylactic adverse reaction to pertussis vaccine as a child.)

• Immunoglobulin received within 60 days before first study vaccination (for mAb see criterion above)

• Autoimmune disease

• Immunodeficiency

Clinically Significant Medical Conditions:

• Clinically significant medical condition, physical examination findings, clinically significant abnormal laboratory results, or past medical history with clinically significant implications for current health. A clinically significant condition or process includes but is not limited to:

• A process that would affect the immune response,

• A process that would require medication that affects the immune response,

• Any contraindication to repeated injections or blood draws,

• A condition that requires active medical intervention or monitoring to avert grave danger to the volunteer's health or well-being during the study period,

• A condition or process for which signs or symptoms could be confused with reactions to vaccine, or

• Any condition specifically listed among the exclusion criteria below.

• Any medical, psychiatric, occupational, or other condition that, in the judgment of the investigator, would interfere with, or serve as a contraindication to protocol adherence, assessment of safety or reactogenicity, or a volunteer's ability to give informed consent

• Psychiatric condition that precludes compliance with the protocol. Specifically excluded are persons with psychoses within the past 3 years, ongoing risk for suicide, or history of suicide attempt or gesture within the past 3 years.

• Current anti-tuberculosis (TB) prophylaxis or therapy

• Asthma other than mild, well-controlled asthma. (Symptoms of asthma severity as defined in the most recent US National Asthma Education and Prevention Program (NAEPP) Expert Panel report). Exclude a volunteer who:

• Uses a short-acting rescue inhaler (typically a beta 2 agonist) daily, or

• Uses moderate/high dose inhaled corticosteroids, or

• In the past year has either of the following:

• Greater than 1 exacerbation of symptoms treated with oral/parenteral corticosteroids;

• Needed emergency care, urgent care, hospitalization, or intubation for asthma.

• Diabetes mellitus type 1 or type 2. (Not excluded: type 2 cases controlled with diet alone or a history of isolated gestational diabetes.)

• Thyroidectomy, or thyroid disease requiring medication during the last 12 months

• Hypertension:

• If a person has been found to have elevated blood pressure or hypertension during screening or previously, exclude for blood pressure that is not well controlled. Well-controlled blood pressure is defined as consistently less than or equal to 140 mm Hg systolic and less than or equal to 90 mm Hg diastolic, with or without medication, with only isolated, brief instances of higher readings, which must be less than or equal to 150 mm Hg systolic and less than or equal to 100 mm Hg diastolic. For these volunteers, blood pressure must be less than or equal to 140 mm Hg systolic and less than or equal to 90 mm Hg diastolic at enrollment.

• If a person has NOT been found to have elevated blood pressure or hypertension during screening or previously, exclude for systolic blood pressure greater than or equal to 150 mm Hg at enrollment or diastolic blood pressure greater than or equal to 100 mm Hg at enrollment.

• Bleeding disorder diagnosed by a doctor (eg, factor deficiency, coagulopathy, or platelet disorder requiring special precautions)

• Malignancy (Not excluded from participation: Volunteer who has had malignancy excised surgically and who, in the investigator's estimation, has a reasonable assurance of sustained cure, or who is unlikely to experience recurrence of malignancy during the period of the study)

• Seizure disorder: History of seizure(s) within past 3 years. Also exclude if volunteer has used medications in order to prevent or treat seizure(s) at any time within the past 3 years.

• Asplenia: any condition resulting in the absence of a functional spleen

• History of hereditary angioedema, acquired angioedema, or idiopathic angioedema.

Related Conditions & MeSH terms

• HIV Infections

Intervention

Biological:
• ALVAC-HIV (vCP2438)
expresses the gene products 96ZM651 gp120 (clade C strain) linked to the sequences encoding the HIV-1 transmembrane anchor (TM) sequence of gp41 (28 amino acids clade B LAI strain) and Gag and Pro (clade B LAI strain). It is formulated as a lyophilized vaccine for injection at a viral titer greater than or equal to 1 × 10^6 cell culture infectious dose (CCID)50 and less than 1 × 10^8 CCID50 (nominal dose of 10^7 CCID50) and is reconstituted with 1 mL of sterile sodium chloride solution (NaCl 0.4%), administered IM as a single 1 mL dose.
• Bivalent subtype C gp120/MF59
clade C TV1.C gp120 Env and clade C 1086.C gp120 Env, each at a dose of 100 mcg, mixed with MF59 adjuvant, administered IM as a single 0.5 mL dose.
• Bivalent subtype C gp120/AS01(B)
clade C TV1.C gp120 Env and clade C 1086.C gp120 Env, each at a dose of 20 mcg or 100 mcg, mixed with AS01B adjuvant, administered IM as a single 0.75 mL dose.
• Placebo
Sodium Chloride for Injection, 0.9%, administered IM.

Locations

Country	Name	City	State
Tanzania	National Institute for Medical Research (NIMR) - Mbeya Medical Research Center (MMRC) Network CRS	Mbeya
United States	Brigham and Women's Hospital Vaccine CRS (BWH VCRS)	Boston	Massachusetts
United States	Fenway Health (FH) CRS	Boston	Massachusetts
United States	Case Clinical Research Site	Cleveland	Ohio
United States	The Hope Clinic of the Emory Vaccine Center CRS	Decatur	Georgia
United States	Vanderbilt Vaccine (VV) CRS	Nashville	Tennessee
United States	Penn Prevention CRS	Philadelphia	Pennsylvania
United States	University of Rochester Vaccines to Prevent HIV Infection CRS	Rochester	New York
United States	Bridge HIV CRS	San Francisco	California
United States	Seattle Vaccine and Prevention CRS	Seattle	Washington
Zambia	Matero Reference Clinic CRS	Lusaka
Zimbabwe	Seke South CRS	Chitungwiza

Sponsors (3)

Lead Sponsor	Collaborator
National Institute of Allergy and Infectious Diseases (NIAID)	GlaxoSmithKline, Sanofi Pasteur, a Sanofi Company

Countries where clinical trial is conducted

United States,  Zambia,  Zimbabwe,  Tanzania, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Number of Participants Reporting Local Reactogenicity Signs and Symptoms During the Vaccine Regimen	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. The maximum grade observed for each symptom over the time frame is presented;	Measured through 7 days after participants' last vaccination at Month 0,1,3, and 6
Primary	Number of Participants Reporting Systemic Reactogenicity Signs and Symptoms During the Primary Vaccine Regimen	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. The maximum grade observed for each symptom over the time frame is presented;	Measured through 7 days after each vaccination at Month 0, 1, 3, and 6
Primary	Frequency of Adverse Events by Relationship to the Study Product	For participants reporting multiple AEs over the time frame, the maximum relationship is counted.	Measured through 30 days after each vaccination at Month 0, 1, 3 and 6.
Primary	Frequency of SAEs, AESIs, and New Chronic Conditions	No SAEs, AESIs, or new chronic conditions were reported over the course of the study	Measured through Month 18.
Primary	Alkaline Phosphatase, AST, ALT in U/L	Laboratory results are summarized by analyte and timepoint.	Measured at Month 0 (Screening) ,0.5(Day 14), 1.5 (Day 42) , 3.5 (Day 98) and 6.5 (Day 182)
Primary	Hemoglobin, Creatinine in g/dL	Laboratory results are summarized by analyte and timepoint.	Measured at Month 0 (Screening) ,0.5(Day 14), 1.5 (Day 42) , 3.5 (Day 98) and 6.5 (Day 182)
Primary	WBC, Platelets, Lymphocytes, Neutrophils in Thousand Cells/Cubic mm	Laboratory results are summarized by analyte and timepoint.	Measured at Month 0 (Screening) ,0.5(Day 14), 1.5 (Day 42) , 3.5 (Day 98) and 6.5 (Day 182)
Primary	AEs or Reactro Leading to Early Participant Withdrawal or Early Discontinuation of Study Products Administration Throughout the Study.	From the study product discontinuation form, study product administration reasons are tabulated by treatment arm	Measured through month 12
Primary	Occurrence of CD4+ T Cell Responses to the HIV Proteins Included in the Vaccine, After the Primary Vaccine Regimen. Measured by Flow Cytometry.	PBMC samples are stimulated with synthetic peptide pools or left unstimulated as a negative control. For each sample, T-cell subset, and peptide pool, response magnitude is % cells expressing IL-2/IFNy after peptide stimulation minus % cells expressing markers after no stimulation. A contingency table is constructed to assess response: stimulation (peptide/none) vs. marker expression (yes/no). A one-sided Fisher's exact test is applied, testing if the number of cells positive for the marker is equal in the stimulated vs. unstimulated cells. A discrete Bonferroni adjustment is made over the peptide pools. A response is positive if p<=0.00001.The number and percentage of participants with positive responses are summarized by peptide pool.	Measured at Month 6.5
Primary	Level of CD4+ T Cell Responses to the HIV Proteins Included in the Vaccine, After the Primary Vaccine Regimen. Measured by Flow Cytometry.	Measured by flow cytometry ICS assay: refer to earlier description for assay methods and analysis variable derivation. The percentage of T-cells expressing IL-1/IFNy are summarized for positive responders only.	Measured at Month 6.5
Primary	Number of Participants With HIV-specific Total IgG Binding Antibody (Vaccine gp120 Panel) Response Magnitude as Assessed by Binding Antibody Multiplex Assay [Time Frame: Measured at Month 12.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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. Samples from post-enrollment visits have positive responses if: (1) net MFI >= an antigen-specific response threshold (defined as the maximum of 100 and the 95th percentile of baseline net MFI), and (2) net MFI > 3 times baseline net MFI, and (3) experimental antigen MFI > 3 times baseline MFI.	Measured at Month 12
Primary	Level of the HIV-specific Total IgG Binding Antibody (Vaccine gp120 Panel) Response Magnitude as Assessed by Binding Antibody Multiplex Assay [Time Frame: Measured at Month 12.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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.	Measured at Month 12
Secondary	Occurrence of CD4+ T Cell Responses to the HIV Proteins Included in the Vaccine, After the Primary Vaccine Regimen. Measured by Flow Cytometry.	PBMC samples are stimulated with synthetic peptide pools or left unstimulated as a negative control. For each sample, T-cell subset, and peptide pool, response magnitude is % cells expressing IL-2/IFNy after peptide stimulation minus % cells expressing markers after no stimulation. A contingency table is constructed to assess response: stimulation (peptide/none) vs. marker expression (yes/no). A one-sided Fisher's exact test is applied, testing if the number of cells positive for the marker is equal in the stimulated vs. unstimulated cells. A discrete Bonferroni adjustment is made over the peptide pools. A response is positive if p<=0.00001.The number and percentage of participants with positive responses are summarized by peptide pool.	Measured at Month 12
Secondary	Level of CD4+ T Cell Responses to the HIV Proteins Included in the Vaccine, After the Primary Vaccine Regimen. Measured by Flow Cytometry.	Measured by flow cytometry ICS assay: refer to earlier description for assay methods and analysis variable derivation. The percentage of T-cells expressing IL-1/IFNy are summarized for positive responders only.	Measured at Month 12
Secondary	Number of Participants With HIV-specific Total IgG Binding Antibody (Vaccine gp120 Panel) Response Magnitude as Assessed by Binding Antibody Multiplex Assay [Time Frame: Measured at Month 6.5.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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. Samples from post-enrollment visits have positive responses if: (1) net MFI >= an antigen-specific response threshold (defined as the maximum of 100 and the 95th percentile of baseline net MFI), and (2) net MFI > 3 times baseline net MFI, and (3) experimental antigen MFI > 3 times baseline MFI.	Measured at Month 6.5
Secondary	Level of the HIV-specific Total IgG Binding Antibody (Vaccine gp120 Panel) Response Magnitude as Assessed by Binding Antibody Multiplex Assay [Time Frame: Measured at Month 6.5]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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.	Measured at Month 6.5
Secondary	Area Under Titration Curve of the HIV-specific Total IgG Binding Antibody (Vaccine gp120 Panel) Response Breadth as Assessed by Binding Antibody Multiplex Assay [Time Frame: Measured at Month 6.5.]	Area under titration curve from serial dilution (AUTC) is calculated using the trapezoidal rule based on the raw MFI values truncated at zero across the log base 10 dilution factors, i.e., the summation of products of raw MFI values and log10(dilution factor). The dilution factor refers to the ratio of the volume of the initial (concentrated) solution (V1) to the volume of the final (dilute) solution (V2), and therefore it is unitless. For example, for a dilution of V1:V2=1:50 of a solution, the corresponding dilution factor is V2/V1=50/1=50.	Measured at Month 6.5
Secondary	Number of Participants With Anti -V1/V2 Scaffold IgG Binding Antibody ( Vaccine V1V2 Panel) Responses. Measured by Binding Antibody Multiplex Assay (BAMA). [Time Frame: Measured at Month 6.5.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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. Samples from post-enrollment visits have positive responses if: (1) net MFI >= an antigen-specific response threshold (defined as the maximum of 100 and the 95th percentile of baseline net MFI), and (2) net MFI > 3 times baseline net MFI, and (3) experimental antigen MFI > 3 times baseline MFI.	Measured at Month 6.5
Secondary	Level of Anti -V1/V2 Scaffold IgG Binding Antibody ( Vaccine V1V2 Panel) Responses. Measured by Binding Antibody Multiplex Assay (BAMA). [Time Frame: Measured at Month 6.5.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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.	Measured at Month 6.5
Secondary	Number of Participants With Anti -V1/V2 Scaffold IgG Binding Antibody ( Vaccine V1V2 Panel) Responses. Measured by Binding Antibody Multiplex Assay (BAMA). [Time Frame: Measured at Month 10.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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. Samples from post-enrollment visits have positive responses if: (1) net MFI >= an antigen-specific response threshold (defined as the maximum of 100 and the 95th percentile of baseline net MFI), and (2) net MFI > 3 times baseline net MFI, and (3) experimental antigen MFI > 3 times baseline MFI.	Measured at Month Month 12
Secondary	Level of Anti -V1/V2 Scaffold IgG Binding Antibody ( Vaccine V1V2 Panel) Responses. Measured by Binding Antibody Multiplex Assay (BAMA). [Time Frame: Measured at Month 12.]	Serum IgG responses were measured on a Bio-Plex instrument using a standardized custom Luminex assay, run at 1:50 dilution. The readout is background-subtracted mean fluorescent intensity (MFI), with background adjustment for an antigen-specific plate level control. For each sample, response magnitude is net MFI, defined as experimental antigen MFI minus reference antigen MFI. Values outside the linear range of the assay are not meaningful and are truncated: net MFI less than 1 is set to 1, and net MFI > 22,000 is set to 22,000. 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.	Measured at Month 12