Safety and Immunogenicity of the Live Attenuated Zika Vaccine rZIKV/D4Δ30-713 in Flavivirus-naïve Adults

Phase I Evaluation of the Safety and Immunogenicity of the Live Attenuated Zika Vaccine rZIKV/D4Δ30-713 in Flavivirus-naïve Adults

This is a phase 1 double-blind, placebo controlled trial designed to evaluate the safety, reactogenicity, and immunogenicity of a single dose of the live attenuated Zika vaccine rZIKV/D4Δ30-713 in adults with no history of previous flavivirus infection.

Study Overview

• Status: Completed
• Conditions: Zika Virus
• Intervention / Treatment: Biological: Single dose of rZIKV/D4Δ30-713 (10^3 PFU) via subcutaneous injection (0.5ml); Biological: Single dose of placebo via subcutaneous injection (0.5ml).; Biological: Single dose of rZIKV/D4Δ30-713 (10^4 PFU) via subcutaneous injection (0.5ml)

Detailed Description

Fifty-six healthy volunteers will be enrolled over 2 sequential cohorts:

Cohort 1: n=28, volunteers will be randomly assigned to a single dose of either vaccine (10^3 PFU, n=20) or placebo (n=8). Cohort 1 will be enrolled and evaluated first. If the vaccine is not found to induce seroconversion to ZIKV in > 80% of subjects inoculated with 10-^3 PFU of the vaccine, a second cohort of volunteers will be enrolled and will be inoculated with 10^4 PFU of vaccine (or placebo).

Cohort 2: n=28, volunteers will be randomly assigned to a single dose of either vaccine (10^4 PFU, n=20) or placebo (n=8).

All volunteers will be followed on an outpatient basis for 6 months following vaccination (13 follow up visits over 180 days). Follow up visits will include clinical assessments as well as sample collection for evaluation of viremia and seroconversion. Sample collection will include blood, urine, saliva, nasopharyngeal or midturbinate swab, vaginal secretion or semen collection on specified visit days throughout the 180 day follow up period.

• Study Type: Interventional
• Enrollment (Actual): 56
• Phase: Phase 1

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Baltimore, Maryland, United States, 21202
      • Johns Hopkins University, Bloomberg School of Public Health
  • Vermont
    • Burlington, Vermont, United States, 05401
      • University of Vermont Medical Center (UVMMC), Clinical Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 46 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Adult male or female between 18 and 50 years of age, inclusive.
• Good general health as determined by physical examination, laboratory screening, and review of medical history.
• Available for the duration of the study, which is approximately 26 weeks.
• Willingness to participate in the study as evidenced by signing the informed consent document.
• Females only: Female subjects of childbearing potential, with the exception noted below, should be willing to use effective contraception and have no plans to undergo IVF (in vitro fertilization) during participation in the trial. Reliable methods of contraception include hormonal birth control, condoms with spermicide, diaphragm with spermicide, surgical sterilization, and intrauterine device. Women must have been on an effective method of birth control for at least 30 days prior to enrollment. All female subjects will be considered as having childbearing potential, except for women who exclusively have sex with women, those who have had a hysterectomy, tubal ligation, or tubal coil (at least 3 months prior to vaccination), or are considered to be post-menopausal, as documented by at least 1 year since last menstrual period with a follicle-stimulating hormone (FSH) level in the menopausal range or at least 24 consecutive months of amenorrhea. Transgender men who have internal female organs and have sex with men will be considered of childbearing potential and should be willing to use effective contraception during the trial. Exception: Females who have sex with females (exclusively) and have no intention of conceiving a child during the study and women whose partners have had a vasectomy will not be required to use contraception, however they will be required to use female condoms and/or dental dams for at least 1 month following vaccination. For women whose sexual partner has had a vasectomy, the vasectomy must have been performed 30 days or more prior to enrollment.

• Males only: Males of reproductive potential should be willing to use barrier contraception for the first 3 months following vaccination* and agree to not donate sperm for the duration of the study.

  • Based on CDC guidance for men returning from ZIKV-endemic areas

Exclusion Criteria:

• Females only: Currently pregnant, as determined by positive β-human choriogonadotropin (HCG) test, or breast-feeding.
• Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, rheumatologic, autoimmune, or renal disease based on history, physical examination, and/or laboratory studies.
• Behavioral, cognitive, or psychiatric disease that, in the opinion of the investigator, affects the subject's ability to understand and cooperate with the requirements of the study protocol.
• Screening laboratory values of Grade 1 or above for absolute neutrophil count (ANC), alanine aminotransferase (ALT), and serum creatinine, as defined in this protocol.
• Any other condition that, in the opinion of the investigator, would jeopardize the safety or rights of a subject participating in the trial, or would render the subject unable to comply with the protocol.
• Any significant alcohol or drug abuse in the past 12 months that has caused medical, occupational, or family problems, as indicated by subject history.
• History of a severe allergic reaction or anaphylaxis.
• Severe asthma (emergency room visit or hospitalization within the last 6 months).
• HIV infection, as indicated by screening and confirmatory assays.
• Hepatitis C virus (HCV) infection, as indicated by screening and confirmatory assays.
• Hepatitis B virus (HBV) infection, as indicated by hepatitis B surface antigen (HBsAg) screening.
• Any known immunodeficiency syndrome.
• History of Guillain-Barrè syndrome.
• Current use of anticoagulant medications (this does not include anti-platelet medication such as aspirin or non-steroidal anti-inflammatory medications).
• Use of immunosuppressive corticosteroids (excluding topical or nasal) or immunosuppressive drugs within 28 days prior to or following inoculation. An immunosuppressive dose of corticosteroids is defined as greater than or equal to 10 mg of a prednisone equivalent per day for greater than or equal to 14 days.
• Receipt of a live vaccine within 28 days or a killed vaccine within 14 days prior to inoculation, or anticipated receipt of any vaccine during the 28 days following inoculation with the exception of COVID-19 vaccines either licensed or under EUA which can be given at any time, however all effort will be made to avoid giving COVID-19 vaccines within the above windows.
• Asplenia.
• Receipt of blood products within the past 6 months, including transfusions or immunoglobulin, or anticipated receipt of any blood products or immunoglobulin during the 28 days following inoculation.
• History or serologic evidence of previous ZIKV or other flavivirus infection (e.g., dengue, yellow fever virus, St. Louis Encephalitis virus, or West Nile virus).
• Previous receipt of a flavivirus vaccine (licensed or experimental).
• Receipt or anticipated receipt of any investigational agent in the 28 days before or after inoculation with the exception of COVID-19 vaccines, either licensed or authorized under EUA.
• Refusal to allow specimen storage for future research.
• Is in isolation or quarantine for SARS-CoV-2 infection or exposure and cannot complete screening or enrollment for this reason.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Cohort 1: Vaccine; Single dose of rZIKV/D4Δ30-713 (10^3 PFU) via subcutaneous injection (0.5ml).	Biological: Single dose of rZIKV/D4Δ30-713 (10^3 PFU) via subcutaneous injection (0.5ml); Administered at a dose of 10^3 plaque-forming units (PFUs) by subcutaneous injection
Placebo Comparator: Cohort 1 - Placebo; Single dose of placebo via subcutaneous injection (0.5ml).	Biological: Single dose of placebo via subcutaneous injection (0.5ml).; Administered by subcutaneous injection.
Experimental: Cohort 2 - Vaccine; Single dose of rZIKV/D4Δ30-713 (10^4 PFU) via subcutaneous injection (0.5ml).	Biological: Single dose of rZIKV/D4Δ30-713 (10^4 PFU) via subcutaneous injection (0.5ml); Administered at a dose of using 10^4 plaque-forming units (PFUs) by subcutaneous injection.
Placebo Comparator: Cohort 2 - Placebo; Single dose of placebo via subcutaneous injection (0.5ml).	Biological: Single dose of placebo via subcutaneous injection (0.5ml).; Administered by subcutaneous injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants With Solicited Local and General Adverse Events (AEs)	Evaluated using the Adverse Event Grading Table in the study protocol.	Solicited AE's assessed every visit through Day 28
To Determine the Immunogenicity of a Single Dose of rZIKV/D4Δ30-713	Determination of the serum plaque reduction neutralization titer 50% (PRNT50) to ZIKV for each subject at Study Day 28 post-inoculation. Seroconversion will be defined as achieving a PRNT50 ≥ 1:10 at any time-point through Study Day 28. The peak PRNT50 to ZIKV through Study Day 28 will be calculated for each subject included in the per-protocol an intent-to-treat analysis and the geometric mean peak titer for vaccinated subjects will be calculated.	Measured through Day 28

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Viremia Induced by Vaccine (Number of Participants With Detectable Virus at Any Time Point)	Assess the frequency, quantity, and duration of viremia (virus in the blood) induced by a single dose of the rZIKV/D4Δ30-713 vaccine. The mean peak viremia, mean day of onset of viremia, and mean duration of viremia will be calculated. Viremia will be detected by culture (infectious virus) and by RT-PCR.	Measured through Day 90
Number of Vaccinees Infected With rZIKV/D4Δ30-713	Determine the number of vaccinees infected with rZIKV/D4Δ30-713. Infection is defined as recovery of infectious vaccine virus from the blood, serum or urine of a subject and/or by seroconversion to ZIKV. Seroconversion will be defined as achieving a PRNT50 ≥ 1:10 by Study Day 90 post-vaccination.	Measured through Day 180
Immunogenicity of rZIKV/D4Δ30-713 in Flavivirus-naïve Subjects	Evaluate the immunogenicity of rZIKV/D4Δ30-713 in flavivirus-naïve subjects as assessed by the PRNT50 to ZIKV, for each subject at Study Day 28, 56, and 90 post-administration of LA Zika vaccine. Expressed as geometric mean peak titer, reciprocal (median). Geometric mean titer was calculated at each time point for only those subjects with a titer of >= 10, reciprocal. Seroconversion was defined as a PRNT(50) of >= 10, reciprocal.	Measured through Day 180
Durability of Antibody Response	Determine the durability of antibody response 26 weeks after vaccination. Neutralizing antibody titers to ZIKV were measured at 0, 28, 56, 90, 150, and 180 days following vaccination, with the peak neutralizing antibody titer determined as the peak titer in the 90 days following vaccination for either dose cohort.	26 Weeks post vaccination
Quantity and Duration of ZIKV Presence	Determine the quantity and duration of ZIKV presence as determined by: The peak virus titer in the blood and the duration of viremia induced by the LA Zika vaccine as determined by RT-PCR and virus culture; The quantity and duration of possible Zika vaccine shedding in urine determined by RT-PCR and virus culture; The quantity and duration of possible Zika vaccine shedding in vaginal secretions determined by RT-PCR and virus culture; The quantity and duration of possible Zika vaccine shedding in semen determined by RT-PCR and virus culture	90 days post vaccination

Collaborators and Investigators

• Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)
• Investigators: Principal Investigator: Kristen Pierce, MD, University of Vermont; Principal Investigator: Anna Durbin, MD, Center for Immunization Research, Johns Hopkins School of Public Health

Study record dates

Study Major Dates

• Study Start (Actual): July 6, 2018
• Primary Completion (Actual): March 18, 2022
• Study Completion (Actual): March 18, 2022

Study Registration Dates

• First Submitted: July 27, 2018
• First Submitted That Met QC Criteria: August 1, 2018
• First Posted (Actual): August 2, 2018

Study Record Updates

• Last Update Posted (Actual): August 5, 2025
• Last Update Submitted That Met QC Criteria: July 16, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: Vaccine; Zika virus
• Additional Relevant MeSH Terms: Vector Borne Diseases; Mosquito-Borne Diseases; Infections; RNA Virus Infections; Virus Diseases; Arbovirus Infections; Flavivirus Infections; Flaviviridae Infections; Zika Virus Infection
• Other Study ID Numbers: CIR 318

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No