A Phase 1 interventional study of 426c.Mod.Core-C4b and 3M-052-AF in HIV Infections, sponsored by HIV Vaccine Trials Network. Not yet recruiting at 1 site in South Africa. Open to participants aged Up to 7 Days, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-09-18.
Sponsored by HIV Vaccine Trials Network · Phase 1, Interventional, and Prevention
The purpose of this study is to evaluate the safety and immunogenicity of 426c.Mod.Core-C4b vaccine adjuvanted with 3M-052-AF + Alum in infants with perinatal HIV exposure who are without HIV at birth
This study will compare the safety and immunogenicity of an experimental HIV vaccine in infants with perinatal HIV exposure who are without HIV at birth. The study vaccine is called 426c.Mod.Core-C4b. The vaccine is mixed with an adjuvant called 3M-052-AF + Alum.
This study is divided into 2 parts: Part A and B. Part A has 4 groups, while Part B has 2 groups. Part A of the study is testing the vaccine alone or in combination with different doses of adjuvant. Part B is testing study vaccine and the safest dose of adjuvants from Part A versus placebo. Depending on their group, participants will receive 426c.Mod.Core-C4b, 426c.Mod.Core-C4b vaccine adjuvanted with 3M-052-AF + Alum, or a placebo by injection at Months 0, 3, and 7.
Additional study visits will occur at Day 1, Week 2, Month 3 1/2, Month 7 1/2, Month 10, Year 1, Year 1 1/2, and Year 1 3/4. Study visits may include physical exams, blood and saliva collection for the infants and questionnaires, counselling, blood, and optional breastmilk collection for the mothers of infants.
4,734 studies on the registry are indexed under HIV Infections; 244 are open to participants now.
This study's planned enrollment of 22 is below the median of 80 across 3,489 interventional studies indexed under HIV Infections.
Browse HIV Infections studies →HIV Vaccine Trials Network is the lead sponsor of 14 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Inclusion Criteria: Mother
Exclusion Criteria: Mother
Inclusion Criteria: Infant
Note: If gestational age at birth is not documented in the infant's available birth records, study staff may assess gestational age at the earliest possible opportunity during the screening period and use this assessment for purposes of eligibility determination.
Exclusion Criteria: Infant
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
CD4 count
The number of CD4 cells, a type of white blood cell, in a given amount of blood. It is used to follow how well the immune system is doing in HIV.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Investigational drug or device
A drug or device being studied in a clinical trial.
It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hepatitis B tests
Hepatitis B is a virus that infects the liver. These are separate tests: HBsAg positive usually means a current infection (a recent vaccination can briefly cause it too); total anti-HBc (HBcAb) positive means an infection now or in the past; HBV DNA measures how much virus is in the blood.
Some studies accept a past infection if HBV DNA is undetectable, sometimes with antiviral medicine during the study. Check what this study allows.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Platelets
Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Clinically significant
Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive 426c.Mod.Core-C4b (20 mcg) alone to be administered as two 0.25-mL intramuscular (IM) doses, one into each thigh at weeks 0, 12, and 28.
Biological: 426c.Mod.Core-C4b
Participants will receive 426c.Mod.Core-C4b (20 mcg) admixed with 3M-052-AF (0.3 mcg) and aluminum hydroxide suspension (Alum) (250 mcg) to be administered as two 0.25-mL IM doses, one into each thigh at weeks 0, 12, and 28.
Biological: 426c.Mod.Core-C4b · Biological: 3M-052-AF · Biological: Aluminum hydroxide suspension (Alum)
Participants will receive 426c.Mod.Core-C4b (20 mcg) admixed with 3M-052-AF (0.75 mcg) and aluminum hydroxide suspension (Alum) (250 mcg) to be administered as two 0.25-mL IM doses, one into each thigh at weeks 0, 12, and 28.
Biological: 426c.Mod.Core-C4b · Biological: 3M-052-AF · Biological: Aluminum hydroxide suspension (Alum)
Participants will receive 426c.Mod.Core-C4b (20 mcg) admixed with 3M-052-AF (1.5 mcg) and aluminum hydroxide suspension (Alum) (250 mcg) to be administered as two 0.25-mL IM doses, one into each thigh at weeks 0, 12, and 28.
Biological: 426c.Mod.Core-C4b · Biological: 3M-052-AF · Biological: Aluminum hydroxide suspension (Alum)
Participants will receive 426c.Mod.Core-C4b (20 mcg) admixed with 3M-052-AF (TBD) and Alum (250 mcg) to be administered as two 0.25-mL IM doses, one into each thigh at weeks 0, 12, and 28.
Biological: 426c.Mod.Core-C4b · Biological: 3M-052-AF · Biological: Aluminum hydroxide suspension (Alum)
Participants will receive Placebo (Tris Sodium Chloride (NaCl) buffer ) to be administered as two 0.25-mL IM doses, one into each thigh at weeks 0, 12, and 28.
Biological: Placebo and Diluent
self-assembling nanoparticle expressing up to 7 molecules of the 426c.Mod.Core envelope immunogen.
3M-052-AF is an aqueous formulation (AF) of a lipidated small molecule imidazoquinoline that is a Toll-like receptor (TLR)7/8 and inflammasome agonist. To be administered as 0.3 mcg, 0.75 mcg, or 1.5 mcg admixed with 426c.Mod.Core-C4b, with Alum
Aluminum hydroxide suspension (Alum) to be administered as 250 mcg (aluminum content) admixed with 426c.Mod.Core-C4b with 3M-052-AF.
Tris-NaCl buffer.
Number of participants reporting local reactogenicity signs and symptoms and number of local reactogenicity signs and symptoms experienced by each participant
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through 14 days following receipt of study product at day 5, week 12, and week 28
Number of participants reporting systemic reactogenicity signs and symptoms symptoms and number of systemic reactogenicity signs and symptoms experienced by each participant,
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through 14 days following receipt of study product at day 5, week 12, and week 28
Number of participants reporting adverse events and overall number of adverse events
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through out the study period
Number of participants reporting serious adverse events and overall number of serious adverse events
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through 12 months post last vaccination at week 28
Number of participants reporting medically attended adverse events and overall number of medically attended adverse events
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through 12 months post last vaccination at week 28
Number of participants reporting adverse events of special interest (AESIs) that are Potential Immune Mediated Medical Conditions (PIMMCs) and overall number of AESIs that are PIMMCs
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through 12 months post last vaccination at week 28
Number of participants reporting AEs leading to early participant withdrawal or permanent discontinuation
Graded according to the Division of AIDS (DAIDS) Table for Grading the Severity of Adult and Pediatric Adverse Events, Version 2.1 \[March 2017\]
Time frame: Measured through 12 months post last vaccination at week 28
Response rate of CD4bs-specific IgG binding antibodies
Measured by binding antibody multiplex assay (BAMA)
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Magnitude of CD4bs-specific IgG binding antibodies
Measured by binding antibody multiplex assay (BAMA)
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Response rate of CD4bs-specific memory B cells
Measured by flow cytometry
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Magnitude of CD4bs-specific memory B cells
Measured by flow cytometry
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Response rate of serum Ab neutralization of vaccine-matched viruses
Measured by TZM-bl pseudoneutralization assay
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Magnitude of serum Ab neutralization of vaccine-matched viruses
Measured by TZM-bl pseudoneutralization assay
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Differential neutralization of HIV-1 strains that are diagnostic for CD4bs bNAb precursors
Measured by TZM-bl assay
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Response rate of serum Ab neutralization of heterologous HIV-1 strains
Measured by TZM-bl assay
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Magnitude of serum Ab neutralization of heterologous HIV-1 strains
Measured by TZM-bl assay
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Response rate (i.e., percentage) of CD4bs-specific, including VRC01-class, B cells
Measured by BCR sequencing of sorted B cells
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Magnitude of CD4bs-specific, including VRC01-class, B cells
Measured by BCR sequencing of sorted B cells
Time frame: Measured 2 weeks after the 3rd vaccination at week 28
Response rate of vaccine-specific and CD4bs-specific binding antibodies
Measured by BAMA
Time frame: Measured 6 months and 12 months after the 3rd vaccination at week 28
Magnitude of vaccine-specific and CD4bs-specific binding antibodies
Measured by BAMA
Time frame: Measured 6 months and 12 months after the 3rd vaccination at week 28
Response rate of CD4bs-specific memory B cells
Measured by flow cytometry
Time frame: Measured 6 months and 12 months after the 3rd vaccination at week 28
Response rate of serum neutralization
Measured by TZM-bl assay
Time frame: Measured 6 months and 12 months after the 3rd vaccination at week 28
Magnitude of serum neutralization
Measured by TZM-bl assay
Time frame: Measured 6 months and 12 months after the 3rd vaccination at week 28
EPI vaccine-specific binding antibody responses
Assessed by Pediatric Vaccine Multiplex Assay (PVMA)
Time frame: Measured 2 weeks, 6 months, and 12 months after the 3rd vaccination at week 28
Start is estimated for Mar 2027; primary completion for Jun 2027, 2 months later.
Of 91 non-industry phase 1 interventional studies under HIV Infections, half reached primary completion within 27 months of starting (the median), counting those still running; a quarter within 18 and three quarters within 46. This study's planned 2 months is below that.
Counting every sponsor, half of 165 studies reached it within 19 months; a quarter within 7 and three quarters within 33.
How these figures are worked out, and which studies are left out of them.
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
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Studies of the drugs tested here: MEDI9197 · Aluminum Hydroxide
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