The purpose of this study is to compare the safety, tolerability, and immunogenicity of CH505TF gp120 produced from stably transfected cells to CH505TF gp120 produced from transiently transfected cells in healthy, HIV-1-uninfected adult participants.

This study will compare the safety, tolerability, and immunogenicity of two experimental HIV vaccines in healthy, HIV-1-uninfected adult participants. The study vaccines are called Stable CH505TF gp120 and Transient CH505TF gp120. The vaccines are mixed with an adjuvant called GLA-SE.

Participants will be randomly assigned to two groups. Participants in Group 1 will receive Stable CH505TF gp120; participants in Group 2 will receive Transient CH505TF. Depending on their group, participants will receive Stable CH505TF gp120 or Transient CH505TF gp120 by injection at Months 0, 2, and 6.

Additional study visits will occur at Months 0.5, 2.5, 6.5, 9, and 12. Study visits may include physical examinations, medical history, vaccine injections, blood and urine collection, risk reduction counseling, and questionnaires. Participants will also be contacted for health information at Month 18.

Inclusion Criteria:

General and Demographic Criteria

• Age of 18 to 50 years
• Access to a participating HIV Vaccine Trials Network (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; completes a questionnaire prior to first vaccination with verbal demonstration of understanding of all questionnaire items answered incorrectly
• Willing to be contacted in person or by phone, text message, or e-mail 6 months after completion of the scheduled clinic visits
• Agrees not to enroll in another study of an investigational research agent before the last required protocol 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 study protocol)

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: alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase 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 US Food and Drug Administration (FDA)-approved enzyme immunoassay (EIA).
• 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 (β-HCG) 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: A volunteer who was assigned female sex at birth must:

  • Agree to use effective contraception for sexual activity that could lead to pregnancy from at least 21 days prior to enrollment until 3 months after the final study vaccination. Effective contraception is defined as using the following methods:

    • Condoms (male or female) with or without a spermicide,
    • Diaphragm or cervical cap with spermicide,
    • Intrauterine device (IUD),
    • Hormonal contraception, or
    • Any other contraceptive method approved by the HVTN 123 Protocol Safety Review Team (PSRT)
    • Successful vasectomy in any partner assigned male sex 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 post vasectomy);

  • 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.

• 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

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: age greater than 45, 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 123 study
• Pregnant or breastfeeding
• Active duty and reserve US 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 123 PSRT will determine eligibility on a case-by-case basis.
• Previous receipt of monoclonal antibodies (mAbs), whether licensed or investigational; the HVTN 123 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 by the HVTN 123 PSRT for vaccines that have subsequently undergone licensure by the FDA. For volunteers who have received control/placebo in an experimental vaccine trial, the HVTN 123 PSRT will determine eligibility on a case-by-case basis. For volunteers who have received an experimental vaccine(s) greater than 5 years ago, eligibility for enrollment will be determined by the HVTN 123 PSRT on a case-by-case basis.
• Live attenuated vaccines received within 30 days before first vaccination or scheduled within 14 days after injection (eg, measles, mumps, and rubella [MMR]; oral polio vaccine [OPV]; varicella; yellow fever)
• Any vaccines that are not live attenuated vaccines and were received within 14 days prior to first vaccination (eg, tetanus, pneumococcal, Hepatitis A or B)
• Allergy treatment with antigen injections within 30 days before first vaccination or that are scheduled within 14 days after first vaccination

Immune System

• Immunosuppressive medications received within 168 days before first 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 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 vaccination
• 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 exclusion criteria: Asthma other than mild, well-controlled asthma. (Symptoms of asthma severity as defined in the most recent 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 three 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.