Group A Streptococcal InfectionPhase 1NCT07616934
A Clinical Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-A1 in Healthy Young Adults
A Phase 1 study testing VAX-A1 Low, VAX-A1 Mid and VAX-A1 High in people with Group A Streptococcal Infection, run by Vaxcyte, Inc. at 1 site in Australia.
Trial summary
This is a phase 1, first-in-human, randomized, double-blind, placebo-controlled, dose-escalation study to evaluate the safety, tolerability, and immunogenicity of VAX-A1 in healthy adults 18-40 years of age. Read more about this study
- Who is it for?
- Ages 18 to 40 yearsHealthy volunteers can take part
- Conditions the study is for
- Group A Streptococcal Infection
- What is being tested?
- VAX-A1 Low, VAX-A1 Mid and VAX-A1 High
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 80 participants
- Where
- 1 siteAustralia
- Study dates
- 1 Jun 2026to Dec 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 40 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Individuals 18-40 years of age (inclusive) at the time of randomization into the study
- Able and willing to complete the informed consent process
- Available for clinical follow-up through the last study visit at 6 months post-Dose 2
- Willing to have blood samples collected, stored indefinitely, and be used for research purposes
- Able to provide proof of identity to the satisfaction of the study staff completing the enrollment process
- Healthy, as defined by absence of clinically significant medical condition, either acute or chronic, as determined by medical history, vital signs, physical examination, screening laboratory test results, TTE and ECG results, and clinical assessment by the Investigator
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- For applicable individuals, postmenopausal (as confirmed by follicle-stimulating hormone [FSH] level at Screening) for at least 1 year, or surgically sterile for at least 6 months prior to dosing
- Individuals of childbearing potential must be not pregnant and not lactating, must have negative urine and serum pregnancy tests at Screening and a negative urine pregnancy test immediately prior to randomization, and agree to use acceptable contraception if heterosexually active. Participants must agree to consistently practice contraception if sexually active at least 7 days prior to enrollment and throughout the duration of the study
- Able to access and use a smartphone, tablet, computer, or other device connected to Wi-Fi or cellular network for completion of an eDiary
Who cannot join
- History of any clinically important cardiac, rheumatologic, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, renal, or other disease as determined by the Investigator. This includes a history of polyarthritis, nephropathy, pericarditis, myocarditis, or hypertension requiring current pharmacologic treatment.
- History of invasive GAS infection (such as toxic shock syndrome, necrotizing fasciitis, bloodstream infection, pleural empyema, meningitis) or poststreptococcal immune mediated disease (such as RHD, ARF, or APSGN)
- Known or suspected autoimmune disease, collagen vascular disease, or impairment/alteration of immune function (e.g., congenital or acquired immunodeficiency)
- Previous or existing diagnosis of human immunodeficiency virus, Hepatitis B virus, or Hepatitis C virus, or a positive serologic test at Screening
- History of malignancy or neoplasm, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer
- Bleeding disorder diagnosed by a physician (e.g., factor deficiency, coagulopathy, or platelet disorder requiring special precautions) resulting in clinically significant bruising or bleeding difficulties with IM injections or blood draws
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- History of severe allergic reaction with generalized urticaria, angioedema, or anaphylaxis to any previous vaccination
- Oral temperature >38.0°C (>100.4°F) or acute illness within 3 days prior to study vaccination (subject may be rescreened)
- Confirmed elevated BP at Screening, defined as systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg measured seated after ≥5 minutes rest and confirmed by repeat measurement
- Physical examination indicating any clinically significant medical condition or inadequate venous access
- Any Grade ≥2 abnormal safety laboratory test at Screening
- Abnormal ESR, or CRP or C3 levels at Screening
- Confirmed microscopic hematuria (>10 RBC/mm³) on UA at Screening. If a potential confounder is present, a repeat UA may be performed during the Screening window; exclusion applies to confirmed microscopic hematuria on an evaluable specimen.
- Evidence of antecedent/recent GAS infection based on anti-DNase B titer ≥ the laboratory reported upper limit of normal (ULN) for the assay used at Screening. Participants with anti-DNase B titer ≥0.8×ULN and <ULN at the initial Screening visit are temporarily ineligible and may be re-screened with repeat anti-DNase B testing 7-21 days after the initial sample; participants will be excluded if the repeat anti-DNase B titer is ≥ULN or demonstrates a clinically meaningful increase of ≥20% relative to the initial screening value, in the absence of an alternative explanation.
- Positive GAS rapid NAAT at Screening or Day 1
- Any finding based on comprehensive TTE at Screening indicative of possible cardiac pathology, including valvular abnormalities defined as mild stenosis or regurgitation.
- Any finding on ECG that is indicative of possible cardiac pathology, including a prolonged PR interval or conduction abnormality
- Receipt of any investigational product within 30 days prior to enrollment into the study, currently participating in another study that includes receipt of an investigational product or procedure, or having plans to receive another investigational product(s) while on study
- Planned or actual administration of any licensed vaccine within 30 days before or after receipt of study vaccine, or within 14 days before or after receipt of study vaccine in the case of influenza and COVID-19 vaccines. Vaccines that are required emergently (e.g., tetanus vaccination in a participant with a contaminated wound) may be given at any time during the study.
- Received blood or blood product (including intravenous immunoglobulin) within 6 months of enrollment into the study
- Receipt of any immunosuppressive therapy, including systemic steroids at a dosage equivalent to ≥0.5 mg/kg/day of prednisone, chronic use of inhaled or nebulized high potency corticosteroids, or use of intra-articular or intrabursal corticosteroids within 1 year of the first study vaccination
- Body mass index (BMI) ≥32 kg/m2 or ≤18 kg/m2
- History of alcohol or drug abuse in the 5 years prior to enrollment, or any history of intravenous drug abuse
- Any medical, psychiatric, or social condition that in the judgment of the Investigator may interfere with the study objectives, impair a participant's ability to give informed consent, pose a risk to the participant, or prevent the participant from completing the study
- Employee of, or first degree relative of any person employed by the Sponsor, the contract research organization (CRO), the Investigator, study site personnel, or site
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Australia1 site, 1 recruiting
- Recruiting
Fusion Clinical Research
Adelaide, South Australia, 5067
Christopher D Rook, MD, +61 8 7088 7900, christopher.rook@cmax.com.au
Christopher Rook, MD
About this study
Official title: A Phase 1, First-in-Human, Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-A1 in Healthy Young Adults
This is a phase 1, first-in-human, randomized, double-blind, placebo-controlled, dose-escalation study to evaluate the safety, tolerability, and immunogenicity of VAX-A1 in healthy adults 18-40 years of age.
- Conditions
- Group A Streptococcal Infection
- Being tested
- Placebo, VAX-A1 Low, VAX-A1 Mid, VAX-A1 High
- Keywords
- Strep A, Streptococcus pyogenes, Safety, Reactogenicity, Immunogenicity, Healthy Adults, Australia
- Medical subject headings
- Streptococcal Infections
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
PlaceboBiological
0.5mL of placebo (normal saline) will be administered into the deltoid muscle
VAX-A1 LowBiological
0.5mL of the low dose VAX-A1 will be administered into the deltoid muscle
VAX-A1 MidBiological
0.5mL of the mid dose VAX-A1 will be administered into the deltoid muscle
VAX-A1 HighBiological
0.5mL of the high dose VAX-A1 will be administered into the deltoid muscle
| Study group | Role | What they receive |
|---|---|---|
| VAX-A1 Low | Experimental | Participants will receive 2 doses of VAX-A1 administered via intramuscular injection at Day 1 and Month 2 Receives: Biological: VAX-A1 Low |
| VAX-A1 Mid | Experimental | Participants will receive 2 doses of VAX-A1 administered via intramuscular injection at Day 1 and Month 2 Receives: Biological: VAX-A1 Mid |
| VAX-A1 High | Experimental | Participants will receive 2 doses of VAX-A1 administered via intramuscular injection at Day 1 and Month 2 Receives: Biological: VAX-A1 High |
| Placebo | Placebo comparator | Participants will receive 2 doses of placebo administered via intramuscular injection at Day 1 and Month 2 Receives: Biological: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Frequency of solicited local reactions (redness, swelling, and pain at injection site)
Measured: up to 7 days after each vaccination
Frequency of solicited systemic adverse events (AE) (fever, headache, fatigue, muscle pain, rash, joint pain, nausea/vomiting, diarrhea)
Measured: up to 7 days after each vaccination
Frequency of laboratory abnormalities identified from protocol-scheduled safety laboratory assessments at 7 days after each vaccination and reported as AE
Measured: 7 days after each vaccination
Frequency of unsolicited AE
Measured: up to 30 days after each vaccination
Frequency of medically attended AE (MAAE)
Measured: Up to 8 months after first vaccination
Frequency of new onset chronic illness (NOCI)
Measured: up to 8 months after the first vaccination
Frequency of serious adverse events (SAE)
Measured: from screening through up to 8 months after first vaccination
Occurrence of AE of special interest (AESI) (acute rheumatic fever [ARF], acute carditis [AC], and acute glomerulonephritis [AGN])
Measured: up to 8 months after the first vaccination
Secondary outcomes (6)
Median value of each safety laboratory parameter assessed 7 days after each vaccination
Measured: 7 days after each vaccination
Median change from baseline to 7 days after each vaccination for each safety laboratory parameter
Measured: 7 days after each vaccination
Serum IgG geometric mean titer (GMT) at each scheduled immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Measured: Prior to each vaccination, 1 month after each vaccination and Month 8
Serum IgG geometric mean fold rise (GMFR) from baseline to each scheduled post-vaccination immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Measured: Prior to each vaccination, 1 month after each vaccination and Month 8
Percentage of participants achieving serum IgG ≥2-fold increase from baseline at each scheduled post-vaccination immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Measured: 1 month after each vaccination and Month 8
Percentage of participants with serum IgG ≥ LLOQ of the assay at each scheduled immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Measured: Prior to each vaccination, 1 month after each vaccination and Month 8
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jun 2026
- Study start1 Jun 2026
- Primary completionDec 2027 (estimated)
- Study completionDec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Group A Streptococcal InfectionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Vaxcyte, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07616934
- Sponsor's protocol ID
- VAXA1-101
- Status last verified
- Jun 2026
- First submitted
- 18 May 2026
- Last updated
- 16 Jun 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Vaxcyte is committed to providing access to anonymized data from the company's clinical trials for the purpose of legitimate scientific research. Requests for data may be addressed to datasharing@vaxcyte.com. Requests must be accompanied by a detailed analysis plan and will be reviewed for scientific validity. Sharing of data will require execution of a data-sharing agreement.
Study at a glance
From the registry record, last updated by the sponsor on 16 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Phase 1, First-in-Human, Randomized, Double-Blind, Placebo-Controlled, Dose-Escalation Study to Evaluate the Safety, Tolerability, and Immunogenicity of VAX-A1 in Healthy Young Adults
- ClinicalTrials.gov ID
- NCT07616934
- Acronym / sponsor ID
- VAXA1-101
- Conditions
- Group A Streptococcal Infection
- Keywords
- Strep A, Streptococcus pyogenes, Safety, Reactogenicity, Immunogenicity, Healthy Adults, Australia
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- Vaxcyte, Inc.Industry (pharma, biotech, devices)
- Study start
- 1 Jun 2026 (actual)
- Primary completion
- Dec 2027 (estimated)
- Study completion
- Dec 2027 (estimated)
- First posted
- 1 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a phase 1, first-in-human, randomized, double-blind, placebo-controlled, dose-escalation study to evaluate the safety, tolerability, and immunogenicity of VAX-A1 in healthy adults 18-40 years of age.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| VAX-A1 Low | Experimental | Biological: VAX-A1 LowParticipants will receive 2 doses of VAX-A1 administered via intramuscular injection at Day 1 and Month 2 |
| VAX-A1 Mid | Experimental | Biological: VAX-A1 MidParticipants will receive 2 doses of VAX-A1 administered via intramuscular injection at Day 1 and Month 2 |
| VAX-A1 High | Experimental | Biological: VAX-A1 HighParticipants will receive 2 doses of VAX-A1 administered via intramuscular injection at Day 1 and Month 2 |
| Placebo | Placebo comparator | Biological: PlaceboParticipants will receive 2 doses of placebo administered via intramuscular injection at Day 1 and Month 2 |
Who may qualify
- Ages
- 18 to 40 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Individuals 18-40 years of age (inclusive) at the time of randomization into the study
- Able and willing to complete the informed consent process
- Available for clinical follow-up through the last study visit at 6 months post-Dose 2
- Willing to have blood samples collected, stored indefinitely, and be used for research purposes
- Able to provide proof of identity to the satisfaction of the study staff completing the enrollment process
Key exclusion criteria (25 listed)
- History of any clinically important cardiac, rheumatologic, endocrinologic, hematologic, hepatic, immunologic, metabolic, urologic, pulmonary, neurologic, dermatologic, psychiatric, renal, or other disease as determined by the Investigator. This includes a history of polyarthritis, nephropathy, pericarditis, myocarditis, or hypertension requiring current pharmacologic treatment.
- History of invasive GAS infection (such as toxic shock syndrome, necrotizing fasciitis, bloodstream infection, pleural empyema, meningitis) or poststreptococcal immune mediated disease (such as RHD, ARF, or APSGN)
- Known or suspected autoimmune disease, collagen vascular disease, or impairment/alteration of immune function (e.g., congenital or acquired immunodeficiency)
- Previous or existing diagnosis of human immunodeficiency virus, Hepatitis B virus, or Hepatitis C virus, or a positive serologic test at Screening
- History of malignancy or neoplasm, except for adequately treated basal cell or squamous cell skin cancer or in situ cervical cancer
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Placebo0.5mL of placebo (normal saline) will be administered into the deltoid muscle | Biological | Placebo |
| VAX-A1 Low0.5mL of the low dose VAX-A1 will be administered into the deltoid muscle | Biological | VAX-A1 Low |
| VAX-A1 Mid0.5mL of the mid dose VAX-A1 will be administered into the deltoid muscle | Biological | VAX-A1 Mid |
| VAX-A1 High0.5mL of the high dose VAX-A1 will be administered into the deltoid muscle | Biological | VAX-A1 High |
Primary outcome
Frequency of solicited local reactions (redness, swelling, and pain at injection site)
Time frame: up to 7 days after each vaccination
Frequency of solicited systemic adverse events (AE) (fever, headache, fatigue, muscle pain, rash, joint pain, nausea/vomiting, diarrhea)
Time frame: up to 7 days after each vaccination
Frequency of laboratory abnormalities identified from protocol-scheduled safety laboratory assessments at 7 days after each vaccination and reported as AE
Time frame: 7 days after each vaccination
Frequency of unsolicited AE
Time frame: up to 30 days after each vaccination
Frequency of medically attended AE (MAAE)
Time frame: Up to 8 months after first vaccination
Frequency of new onset chronic illness (NOCI)
Time frame: up to 8 months after the first vaccination
Frequency of serious adverse events (SAE)
Time frame: from screening through up to 8 months after first vaccination
Occurrence of AE of special interest (AESI) (acute rheumatic fever [ARF], acute carditis [AC], and acute glomerulonephritis [AGN])
Time frame: up to 8 months after the first vaccination
6 secondary outcomes
Median value of each safety laboratory parameter assessed 7 days after each vaccination
Time frame: 7 days after each vaccination
Median change from baseline to 7 days after each vaccination for each safety laboratory parameter
Time frame: 7 days after each vaccination
Serum IgG geometric mean titer (GMT) at each scheduled immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Time frame: Prior to each vaccination, 1 month after each vaccination and Month 8
Serum IgG geometric mean fold rise (GMFR) from baseline to each scheduled post-vaccination immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Time frame: Prior to each vaccination, 1 month after each vaccination and Month 8
Percentage of participants achieving serum IgG ≥2-fold increase from baseline at each scheduled post-vaccination immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Time frame: 1 month after each vaccination and Month 8
Percentage of participants with serum IgG ≥ LLOQ of the assay at each scheduled immunogenicity sample collection visit for each vaccine antigen (SLO, C5a pep, SpyAD, GAC)
Time frame: Prior to each vaccination, 1 month after each vaccination and Month 8
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Jun 2026.
- Individual participant dataSharing planned: Yes. Vaxcyte is committed to providing access to anonymized data from the company's clinical trials for the purpose of legitimate scientific research. Requests for data may be addressed to datasharing@vaxcyte.com. Requests must be accompanied by a detailed analysis plan and will be reviewed for scientific validity. Sharing of data will require execution of a data-sharing agreement.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing VAX-A1 Low, VAX-A1 Mid and VAX-A1 High in people with Group A Streptococcal Infection, run by Vaxcyte, Inc. at 1 site in Australia.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 25 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 16 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Australia. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Clinical Development (650-837-0111, Clinicaltrialsgov@vaxcyte.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Frequency of solicited local reactions (redness, swelling, and pain at injection site) (time frame: up to 7 days after each vaccination). The study lists 8 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Jun 2026.