ClinicalTrials.gg
Active, not recruitingNCT05304351Updated Sep 30, 2025

Safety and Immunogenicity of CRV-101 Vaccine for the Prevention of Herpes Zoster in Adults Aged 50 Years and Older

A Phase 2 interventional study of Amezosvatein Antigen High Dose Arm A and Amezosvatein Antigen Low Dose Arm B in Herpes Zoster and Shingles, sponsored by Curevo Inc. Active, not recruiting at 14 sites in United States. Open to participants aged 50 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-09-30.

Sponsored by Curevo Inc · Phase 2, Interventional, and Prevention

From the registry’s dates

  • Primary completion was expected by Jun 2026, 4 months ago, but the record still lists the study as active, not recruiting.
Phase
Phase 2
Study type
Interventional
Enrollment
1,516
Allocation
Randomized
Ages
50 Years and older
Sex
All
01

Study summary

The purpose of this study is to assess the safety and immunogenicity of amezosvatein (CRV-101), an investigational vaccine compared to Shingrix® for the prevention of herpes zoster in adults aged 50 years and older

Read the detailed description

In the first part of the trial, participants will be randomized 1:1:1 to amezosvatein high antigen dose (Arm A), amezosvatein low antigen dose (B), or Shingrix (C). In the second part of the trial, participants will be randomized 5:1 to receive amezosvatein adjuvant dose D or Shingrix (E), adjuvant dose F or Shingrix (G), or adjuvant dose H or Shingrix (I). In the third part of the trial, participants will be randomized 3:1 to receive amezosvatein adjuvant dose J or Shingrix (K) or amezosvatein adjuvant dose L or Shingrix (M). Both study vaccines, amezosvatein and Shingrix, will be administered by intramuscular injection on Month 0 and Month 2. Safety, reactogenicity, and immunogenicity analysis will be performed overall and by age group. Participants will be followed for safety, immunogenicity, and herpes zoster cases from Day 0 to the main study end (Month 14), and through the long-term follow up (LTFU) extension period of up to 5 additional years.

02

Conditions studied

  • Herpes Zoster
  • Shingles

Keywords

  • Herpes Zoster
  • Shingles
  • Varicella Zoster Virus
  • Vaccine
03

In context

Herpes Zoster

299 studies on the registry are indexed under Herpes Zoster; 55 are open to participants now.

This study's enrollment of 1,516 is above the median of 160 across 247 interventional studies indexed under Herpes Zoster.

Browse Herpes Zoster studies →

Lead sponsor

Curevo Inc is the lead sponsor of 2 studies on the registry; none are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
50 Years and older
Sexes eligible
All
Accepts healthy volunteers
Yes

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

Participants are eligible to be included in the study only if all of the following criteria apply:

  1. Male and non-pregnant female participant must be ≥50 years of age inclusive, at the time of signing the .

    • Arms A, B, C, J, K, L, and M will enroll participants ≥50 years of age
    • Arms D, E, F, G, H, and I will enroll participants ≥50 to \<70 years of age
  2. Participants who are healthy as determined by medical evaluation including comprehensive medical history, comprehensive physical examination, vital signs*, and screening laboratory tests conducted no more than 30 days prior to first study injection administration (Day 0).

    • Vital signs within grade 1 on the severity grading scale, excluding temperature, are allowed. If vital sign parameter meets grade 2 criteria, then subject must be excluded. Vital signs may be repeated 3 times after a period of rest as needed if transient abnormal fluctuation is suspected.
  3. (Applicable only for arms A through I) Completed an Emergency Use Authorization (EUA) or Conditional Marketing Authorization or licensed initial COVID-19 vaccine series (as applicable) ≥30 days prior to enrollment (i.e., at least 30 days prior to the Day 0 visit).
  4. Screening laboratory values [sodium, potassium, blood urea nitrogen (BUN), (ALT), Aspartate Aminotransferase (AST), total , alkaline phosphatase, creatinine, random glucose, white blood cell count with differential, , and count] must be within normal ranges or considered not by the PI.**
  5. Negative 1/2 antibody, surface antigen (HBsAg), and virus (HCV) antibody at screening. If HIV 1/2 antibody is positive, and confirmation testing is negative the participant may be enrolled.
  6. Normal urinalysis or, if abnormal, urinalysis determined to be not clinically significant by the PI at screening.**

    • Screening laboratory values that are abnormal but are considered abnormal due to an acute illness or process may be repeated once. Careful consideration regarding enrolling subjects with screening lab values meeting grade 2 severity that are considered not clinically significant must be made as there is less room for fluctuations to increase to gr ade 3 (severe) lab events.
  7. A female participant is eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies:

    • Is a woman of nonchildbearing potential (WONCBP). OR
    • Is a woman of (WOCBP) and using an acceptable method as defined below during the 30 days prior to Day 0 (i.e., the first study vaccine) and is willing to continue to do so during the study until at least 90 days after the last dose of study vaccine, and agrees not to donate eggs (ova, oocytes) for the purpose of reproduction during this period. The investigator should evaluate the potential for contraceptive method failure (e.g., noncompliance, recently initiated) in relation to the timing of the first dose of study vaccine.
    • A WOCBP must have a negative serum pregnancy test at screening and a negative urine pregnancy test on the day of each study vaccine (prior to vaccination). If a urine test cannot be confirmed as negative (e.g., an ambiguous result), a serum pregnancy test is required. In such cases, the participant must be excluded from participation if the serum pregnancy result is positive.

    WONCBP is as defined as

    • : A postmenopausal state is defined as least 12 months of spontaneous amenorrhea.
    • Permanently sterile: Permanent sterilization methods include hysterectomy, bilateral salpingectomy, bilateral tubal occlusion/ligation procedures, bilateral oophorectomy, and successful Essure® placement (permanent, non-surgical, non-hormonal sterilization) with documented radiological confirmation test at least 90 days after the procedure, and still menstruating or \<1 year since of the last menses if menopausal.

    WOCBP is defined as

    • Any woman or adolescent who has begun menstruation. Acceptable contraception methods include, but are not limited to, sexual abstinence, monogamous relationship with vasectomized partner who has been vasectomized for 6 months or more prior to the participant receiving study product, barrier methods such as condoms or diaphragms with spermicide or foam, effective intrauterine devices, NuvaRing®, and licensed hormonal methods such as implants, injectables, or oral contraceptives ("the pill").
  8. Capable of understanding and giving signed informed consent, which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol prior to any screening procedures.
  9. Willing to abstain from donating whole blood or blood derivatives until after Day 84 visit, and within 60 days prior to each study visit after Day 84.
  10. Be able and willing to participate in all study visits and be reachable by telephone or personal contact by the study site personnel.
  11. Participants who the investigator believes will comply with the requirements of the protocol (e.g., completion of the diary cards, return for follow-up visits, have regular contact to allow evaluation during the study).
  12. Capable of understanding and completing diary card. Arms A, B, and C use electronic diary and require access to web browser. Arms D through M use paper diary

Exclusion criteria

Exclusion Criteria

Participants are excluded from the study if any of the following criteria apply:

  1. History of herpes zoster (shingles).
  2. History or presence of acute or chronic illness (including cardiovascular, pulmonary, neurological, hepatic, rheumatic, hematological, metabolic, gastrointestinal, endocrinologic or renal disorders, or uncontrolled hypertension) which in the opinion of the Principal Investigator, may interfere with the evaluation of the safety or immunogenicity of the vaccine.
  3. History of disease or suspected or immunodeficient condition resulting from disease (e.g., , infection) or immunosuppressive/cytotoxic therapy (e.g., medications used during cancer chemotherapy, organ transplantation, or to treat autoimmune disorders) that is likely to affect the immune response to vaccination as determined by the PI.
  4. Rash, tattoos, or any other dermatological condition that could adversely affect the vaccine injection site or interfere with its evaluation.
  5. Abnormal blood pressure >150 mm Hg systolic or >95 mm Hg diastolic prior to first study injection administration (Day 0).***

    *** If abnormal, BP may be repeated up to 3 times after a rest period of 5 minutes between each measurement.

  6. History of significant psychiatric illness (including history of suicidal ideation or attempt) with or without current medication.
  7. ≥40kg/m2 at screening (where BMI >34.9 kg/m2, clinically-significant abnormal serum glucose at screening determined by the PI, or clinically-significant diseases or medical conditions, as determined by the PI, is exclusionary.)
  8. Significant underlying illness that in the opinion of the investigator would be expected to prevent completion of the study (e.g., life-threatening disease likely to limit survival to less than 4 years).
  9. Acute disease and/or fever at the time of enrollment (Day 0).

    1. Fever is defined as body temperature ≥38 °C (100.4 °F); oral acquisition will be the preferred route for recording temperature throughout this study.
    2. Participants with a minor illness (such as mild diarrhea or mild upper respiratory infection) without fever may be enrolled after resolution of the minor illness, at the discretion of the investigator.
  10. Immunized with a vaccine against herpes zoster (Zostavax®, Shingrix®, other licensed or HZ vaccine).
  11. Prior varicella vaccination at any time.
  12. Received any vaccine within 30 days prior to enrollment (Day 0) or received any non-investigational immunizations while on study except for seasonal influenza, pneumococcal vaccines, other vaccines per the ACIP recommendations, or any licensed or emergency use authorization or conditional marketing authorized COVID-19 booster. Administration of these immunizations must not occur until 30 days after the final study vaccination and completion of the Day 84 immunology blood draw and must not occur within the 30 days prior to each on-study immunology blood draw after Day 84. Receipt of any VZV vaccine is prohibited on the study.
  13. Use of any medication that, in the opinion of the Principal Investigator, may interfere with the evaluation of the safety or immunogenicity of the vaccine.
  14. (a) Chronic administration (defined as more than 14 days in total) of immunosuppressants or other immune-modifying drugs (e.g., oral or injected , such as prednisone; high-dose inhaled steroids; biologics (e.g., tumor necrosis factor [TNF] inhibitor, or other cytokine inhibitors within 14 days of Day 0 through Day 84, and within 14 days of each on study immunogenicity blood draw after Day 84; Exclusionary corticosteroid administration is defined as prednisone >20 mg/day (or equivalent) for any frequency; low-dose inhaled and topical and ocular steroids are allowed; (b) or cytotoxic therapies, such as chemotherapy drugs or radiation, from 180 days prior to enrollment, during the study through Day 421.

    Participants who meet this criterion from 14a and 14b after Day 56, should continue to be followed for safety and immunogenicity but will not be in included in the per protocol population from the date of meeting the criterion.

  15. Received a blood transfusion, , plasma, or immunoglobulin 90 days prior to first dose of study vaccine (Day 0) or planned administration of such products during the study.
  16. Donated blood products (platelets, whole blood, plasma, etc.) within 60 days prior to enrollment (Day 0).
  17. Participation in another experimental protocol which includes the receipt of any investigational products/vaccines or devices within 90 days prior to enrollment (Day 0) in this study, or planned participation in another experimental protocol which includes investigational product/vaccine or device receipt during the study period through D421*. After the D421 visit, participation in another clinical study and with concurrent receipt of another experimental investigational product/vaccine or device is allowed with medical monitor approval. Any other investigational product/vaccine with immune modulating effect which would complicate the assessment of humoral and cellular responses, including investigational vaccines, must not be used 60 days prior to each LTFU extension year visit. Receipt of another experimental VZV vaccine or HSV vaccine is prohibited on the study.

    *Prior to Day 421, concurrent participation in a study which previously included investigational product/vaccine receipt but is no longer receiving investigational products/vaccine, such as in an observational phase of the other study, is allowed.

  18. History of previous anaphylaxis or severe allergic reaction to vaccines or sensitivity to any of the study vaccines, or components thereof, or drug or other allergy that, in the opinion of the investigator, contraindicates participation in the study.
  19. Known or suspected alcohol or drug abuse within 5 years prior to enrollment (Day 0).
  20. ≥20 pack-years for a current smoker or a former smoker at screening.
  21. Unlikely to cooperate with the requirements of the study protocol, or deemed unreliable in attending study visits, or otherwise determined by the investigator not to be a good candidate to participate in this study.

[protocol v8.0]

Terms in these criteria, in plain language(18)

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.

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.

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.

Bilirubin

A yellow substance made when red blood cells are broken down, which the liver clears. A high level can mean a problem with the liver or the bile ducts.

Criteria often allow more for people with Gilbert’s syndrome, a harmless inherited condition that raises bilirubin.

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).

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.

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.

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.

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.

Hepatitis C tests

Hepatitis C is a virus that infects the liver. An HCV antibody test can stay positive after an infection has cleared (and is occasionally positive without one); an HCV RNA test shows whether the virus is there now.

After treatment, hepatitis C counts as cured when HCV RNA is still undetectable 12 weeks or more after the treatment ended. Studies often accept people cured this way.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Autoimmune disease

A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.

Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.

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.

Cancer (malignancy)

Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.

Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.

BMI (body mass index)

Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.

What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.

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.

Corticosteroids (steroids)

Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.

Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.

05

Study design

Phase
Phase 2
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Quadruple (Participant, Care provider, Investigator, Outcomes assessor)
Enrollment
1,516 participants (actual)

Study arms

  • Experimental
    Arm A

    Investigational Vaccine

    Biological: Amezosvatein Antigen High Dose Arm A

  • Experimental
    Arm B

    Investigational Vaccine

    Biological: Amezosvatein Antigen Low Dose Arm B

  • Active comparator
    Arm C

    Active comparator

    Biological: Shingrix

  • Experimental
    Arm D

    Investigational Vaccine

    Biological: Amezosvatein Adjuvant Dose Arm D

  • Active comparator
    Arm E

    Active Comparator

    Biological: Shingrix

  • Experimental
    Arm F

    Investigational Vaccine

    Biological: Amezosvatein Adjuvant Dose Arm F

  • Active comparator
    Arm G

    Active Comparator

    Biological: Shingrix

  • Experimental
    Arm H

    Investigational Vaccine

    Biological: Amezosvatein Adjuvant Dose Arm H

  • Active comparator
    I

    Active Comparator

    Biological: Shingrix

  • Experimental
    Arm J

    Investigational Vaccine

    Biological: Amezosvatein Adjuvant Dose Arm J

  • Active comparator
    Arm K

    Active Comparator

    Biological: Shingrix

  • Experimental
    Arm L

    Investigational Vaccine

    Biological: Amezosvatein Adjuvant Dose Arm L

  • Active comparator
    Arm M

    Active Comparator

    Biological: Shingrix

Interventions

  • BiologicalAmezosvatein Antigen High Dose Arm A

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalAmezosvatein Antigen Low Dose Arm B

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalShingrix

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalAmezosvatein Adjuvant Dose Arm D

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalAmezosvatein Adjuvant Dose Arm F

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalAmezosvatein Adjuvant Dose Arm H

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalAmezosvatein Adjuvant Dose Arm J

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

  • BiologicalAmezosvatein Adjuvant Dose Arm L

    Suspension for injection administered intramuscularly (IM) in the deltoid region of the non-dominant arm in Month 0 and Month 2 per study schedule

06

What researchers measure

Primary outcomes

  1. Occurrence of solicited local and systemic signs and symptoms

    Occurrence, severity, and duration of solicited local injection site reactions within 7 days (Day 0-Day 6) following each vaccination. (i.e., pain, redness, swelling) Occurrence, severity, and duration of solicited systemic reactions within 7 days (Day 0-Day 6) following each vaccination. (i.e., myalgia, fatigue, headache, chills, fever)

    Time frame: Day 0-Day 6 for each vaccination timepoint

  2. To compare the reactogenicity of amezosvatein to that of the standard 2-dose schedule of Shingrix®

    Comparison of the proportion of participants reporting solicited local and systemic reactogenicity events following each vaccination

    Time frame: Day 0-Day 6 for each vaccination timepoint

  3. Occurrence of unsolicited non-serious adverse events

    Occurrence, severity, and relationship to vaccination of unsolicited adverse events within 29 days (Day 0-Day 28) following each vaccination

    Time frame: Day 0-Day 28 following each vaccination

  4. Occurrence of serious adverse events (SAEs)

    Occurrence and relationship to vaccination of all serious adverse events (SAE) from after first vaccination (Day 0) to main study end (Day 421 \[Month 14\])

    Time frame: Day 0 - Day 421 [Month 14] (as noted in description)

  5. Occurrence of adverse events (AEs) of special interest

    Occurrence of any Potential Immune-Mediated Medical Conditions (PIMMCs) from post first vaccination (Day 0) to main study end (Day 421 \[Month 14\]) Medically attended adverse events (MAAEs) from post first vaccination (Day 0) to study end (Day 421 \[Month 14\])

    Time frame: Day 0 - Day 421 [Month 14] (as noted in description)

  6. To evaluate safety as measured by hematology and biochemistry parameters

    Occurrence, intensity, and relationship to vaccination of clinically significant hematologic and biochemical adverse events at at Day 7 and Day 63

    Time frame: Day 7 and Day 63

  7. Vaccine protein-specific antibody concentrations (GMC) elicited by vaccination between Month 0 and Month 3

    Assess humoral immune response as determined by Enzyme-linked Immunosorbent Assay (ELISA)

    Time frame: Month 3

  8. Vaccine Response Rate (≥ 4 fold increase in antibody concentration from pre-vaccination) at Month 3 for arms A, B, and C

    • Assess humoral immune response as determined by Enzyme-linked Immunosorbent Assay (ELISA)

    Time frame: Month 3

  9. To compare the humoral immune response of Shingrix® to amezosvatein

    Comparison of humoral response between amezosvatein and Shingrix at Month 3

    Time frame: Month 3

Secondary outcomes

  1. Fold rise of vaccine protein-specific antibody concentrations elicited in response to vaccination for durability post Month 3

    • Assess humoral immune response as determined by Enzyme-linked Immunosorbent Assay (ELISA)

    Time frame: Month 3

  2. Anti-Varicella Zoster Virus (VZV) neutralizing antibody titer in response to vaccination between Day 0 and Month 3 for arms A, B, and C

    To assess the functional humoral immune response to vaccination (sub-study)

    Time frame: Month 3

  3. Frequency of vaccine protein-specific CD4+ T cells expressing at least 2 activation markers in response to vaccination between Month 0 and Month 3 for arms A, B, and C

    To assess the cell-mediated immunity (CMI) immune response to vaccination as determined by intracellular cytokine staining (ICS)

    Time frame: Month 3

  4. To compare the frequency of vaccine protein-specific CD4+ T cells expressing at least 2 activation markers of Shingrix® to amezosvatein between Month 0 and Month 3 for arms A, B, and C.

    To compare CMI immune response between amezosvatein and Shingrix® at Month 3

    Time frame: Month 3

  5. CMI Vaccine Response rate (≥ 2-fold increase in the frequency of vaccine protein-specific CD4+ T cell expressing at least 2 activation markers) at Month 3 for arms A, B, and C.

    To assess the cell-mediated immunity (CMI) immune response to vaccination as determined by intracellular cytokine staining (ICS)

    Time frame: Month 3

  6. Vaccine Response Rate (≥ 4 fold increase in antibody concentration from pre-vaccination) at Month 3 for arms D through M

    Assess humoral immune response as determined by Enzyme-linked Immunosorbent Assay (ELISA)

    Time frame: Month 3

Other outcomes

  1. Vaccine protein-specific antibody concentrations elicited by response to vaccination for durability post Month 3

    • Durability of humoral immunogenicity as determined by Enzyme-linked Immunosorbent Assay (ELISA)

    Time frame: Month 14, and LTFU up to 5 additional years.

  2. Fold rise of vaccine protein-specific antibody concentrations elicited in response to vaccination post Month 3

    • Durability of humoral immunogenicity as determined by Enzyme-linked Immunosorbent Assay (ELISA)

    Time frame: Month 14, and LTFU up to 5 additional years.

  3. Frequency of vaccine protein-specific CD4+ T cells expressing at least 2 activation markers in response to vaccination for durability post Month 3

    To assess the cell-mediated immunogenicity as determined by intracellular cytokine staining (ICS)

    Time frame: Month 0, Month 14, and in LTFU up to 5 additional years.

  4. To assess the correlation between vaccine protein-specific Ab concentrations, Anti-VZV neutralizing Ab titer, and frequency of vaccine protein-specific CD4+ T cells expressing >=2 activation markers for each vaccine and correlation across vaccines

    The immunogenicity of amezosvtein alone or compared to Shingrix® will be further evaluated by methods to be determined. Exploratory analyses may include conducting analyses related to furthering the understanding of immunity to VZV and further characterization of the immune responses elicited by amezosvatein and/or in comparison to Shingrix

    Time frame: Main study (Month 0 - Month 14) and LTFU up to 5 additional years.

  5. To evaluate the incidence of clinically confirmed herpes zoster cases

    Occurrence of clinically confirmed herpes zoster cases during the entire main study and LTFU extension period

    Time frame: Main study (Month 0 - Month 14) and LTFU up to 5 additional years.

  6. Frequency of vaccine protein-specific CD4+ T cells expressing at least 2 activation markers in response to vaccination between Month 0 and Month 3 for arms J, K, L, and/or M for dose selected for further development

    To assess the cell-mediated immunity (CMI) immune response to vaccination as determined by intracellular cytokine staining (ICS)

    Time frame: Month 3

  7. To compare Shingrix® to amezosvatein on the frequency of vaccine protein-specific CD4+ T cells expressing at least 2 activation markers between Month 0 and Month 3 for arms J, K, L, and/or M for dose selected for further development

    To compare CMI immune response between amezosvatein and Shingrix® at Month 3

    Time frame: Month 3

  8. CMI Vaccine Response rate (≥ 2-fold increase in the frequency of vaccine protein-specific CD4+ T cell expressing at least 2 activation markers) at Month 3 for arms J, K, L, and/or M for dose selected for further development

    To assess the cell-mediated immunity (CMI) immune response to vaccination as determined by intracellular cytokine staining (ICS)

    Time frame: Month 3

  9. Occurrence of serious adverse events in long term follow up (LTFU) period

    Occurrence of serious adverse events in long term follow up (LTFU) period

    Time frame: LTFU period post Day 421 up to 5 additional years

  10. Occurrence and relationship to vaccination of all serious adverse events (SAE) related or fatal in study participants in LTFU period

    Occurrence and relationship to vaccination of all serious adverse events (SAE) related or fatal in study participants in LTFU period

    Time frame: LTFU period post Day 421 up to 5 additional years

  11. Occurrence of adverse events (AEs) of special interest

    Occurrence of any Potential Immune-Mediated Medical Conditions (PIMMCs) in LTFU period

    Time frame: LTFU period post Day 421 up to 5 additional years

07

Study locations

14 sites
  • Curevo Investigational Site
    Tempe, Arizona 85281, United States
  • Curevo Investigational Site
    Coral Gables, Florida 33134, United States
  • Curevo Investigational Site
    Tampa, Florida 33616, United States
  • Curevo Investigational Site
    Oak Brook, Illinois 60523, United States
  • Curevo Investigational Site
    Lenexa, Kansas 66219, United States
  • Curevo Investigational Site
    Newton, Kansas 67114, United States
  • Curevo Investigational Site
    Lexington, Kentucky 40509, United States
  • Curevo Investigational Site
    Las Vegas, Nevada 89119, United States
  • Curevo Investigational Site
    Edmond, Oklahoma 73013, United States
  • Curevo Investigational Site
    Knoxville, Tennessee 37909, United States
  • Curevo Investigational Site
    Austin, Texas 78745, United States
  • Curevo Investigational Site
    Dallas, Texas 75251, United States
  • Curevo Investigational Site
    Euless, Texas 76040, United States
  • Curevo Investigational Site
    Salt Lake City, Utah 84107, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 30, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05304351
Lead sponsor
Curevo Inc
Responsible party
Sponsor
First posted
Mar 31, 2022
Start date
Feb 2, 2022
Primary completion
Jun 30, 2026 (estimated)
Completion
Mar 6, 2032 (estimated)
Last update
Sep 30, 2025

Study contacts

Lisa Shelton, ARNP
study director · Curevo Inc
Guy De La Rosa, MD
study director · Curevo Inc

Oversight

Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
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Not currently enrolling

This study is active, not recruiting, as verified in Sep 2025. You cannot join it, but the record below documents what was studied.

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Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

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