A Study of Zika Vaccine mRNA-1893 in Adult Participants Living in Endemic and Non-Endemic Flavivirus Areas

NCT ID: NCT04917861

Last Updated: 2025-09-25

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2
• Total Enrollment: 808 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2021-06-07
• Study Completion Date: 2024-07-26

Brief Summary

This clinical study will evaluate the safety, tolerability, and reactogenicity of 2 dose levels of messenger RNA (mRNA)-1893 Zika vaccine in comparison to a placebo control in healthy participants who are flavivirus-seronegative and in participants who are flavivirus-seropositive.

Conditions

Zika Virus

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: PREVENTION
• Blinding Strategy: QUADRUPLE

Study Groups

mRNA-1893 Low Dose (2-Dose Regimen)

Participants will receive mRNA-1893 at a low dose level administered as a 2-dose regimen with 28-day (-3/+7 days) interval between vaccinations (administered on Day 1 and Day 29).

Group Type: EXPERIMENTAL

mRNA-1893

Intervention Type: BIOLOGICAL

Solution for injection

mRNA-1893 High Dose (2-Dose Regimen)

Participants will receive mRNA-1893 at a high dose level administered as a 2-dose regimen with 28-day (-3/+7 days) interval between vaccinations (administered on Day 1 and Day 29).

Group Type: EXPERIMENTAL

mRNA-1893

Intervention Type: BIOLOGICAL

Solution for injection

mRNA-1893 High Dose (1-Dose Regimen)

Participants will receive placebo matching to mRNA-1893 on Day 1 and mRNA-1893 at a high dose level administered as a 1-dose regimen (administered on Day 29). There will be 28-day (-3/+7 days) interval between vaccinations.

Group Type: EXPERIMENTAL

mRNA-1893

Intervention Type: BIOLOGICAL

Solution for injection

Placebo

Intervention Type: BIOLOGICAL

0.9% sodium chloride solution for injection

Placebo

Participants will receive placebo matching to mRNA-1893 administered as a 2-dose regimen with 28-day (-3/+7 days) interval between vaccinations (administered on Day 1 and Day 29).

Group Type: PLACEBO_COMPARATOR

Placebo

Intervention Type: BIOLOGICAL

0.9% sodium chloride solution for injection

Interventions

mRNA-1893

Solution for injection

Intervention Type: BIOLOGICAL

Placebo

0.9% sodium chloride solution for injection

Intervention Type: BIOLOGICAL

Other Intervention Names

Zika vaccine

Eligibility Criteria

Inclusion Criteria

• Understands and agrees to comply with the study procedures and provides written informed consent.
• According to investigator assessment, is in good general health and can comply with study procedures.
• Female participants of childbearing potential may be enrolled in the study if the participant: has a negative pregnancy test at the Eligibility Visit and on the day of the first investigational product (IP) injection; has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first IP injection; has agreed to continue adequate contraception through 3 months following the last IP injection; and is not currently breastfeeding.

Exclusion Criteria

• Participant is acutely ill or febrile (temperature ≥38.0°Celsius/100.4°Farenheight) on the day of the first or second vaccination.
• Participant had prior administration of a ZIKV vaccine candidate during a clinical study investigation.
• Participant had prior administration of a marketed dengue vaccine or dengue vaccine candidate under clinical study investigation.
• Participant has a body mass index (BMI) from ≤18 or ≥35 kilograms (kg)/square meter (m^2).
• Participant has a history of myocarditis, pericarditis, or myopericarditis.
• Participant has a history of a diagnosis or condition that, in the judgement of the investigator, is clinically unstable or may affect participant safety, assessment of safety endpoints, assessment of immune response, or adherence to study procedures. "Clinically unstable" is defined as a diagnosis or condition requiring significant changes in management or medication within the 2 months prior to screening and includes ongoing work-up of an undiagnosed illness that could lead to a new diagnosis or condition.
• Participant has any medical, psychiatric, or occupational condition, including reported history of drug or alcohol abuse, that in the opinion of the investigator, might pose a risk due to participation in the study or could interfere with the interpretation of study results.
• Participant has as a history of anaphylaxis, urticaria, or other significant AR requiring medical intervention after receipt of a vaccine, including an mRNA vaccine or any components of an mRNA vaccine.
• Participant has received or plans to receive a nonstudy vaccine (including authorized or approved vaccines for the prevention of COVID-19) ≤28 days prior to the first IP injection or within 28 days prior to or after any IP injection. Licensed influenza vaccine received within 14 days prior to the first IP injection or plans to receive a licensed influenza vaccine 14 days prior to through 14 days following each IP injection are not exclusionary.
• Participant has received systemic immunoglobulins or blood products within 3 months prior to the day of enrollment.
• Participant has donated ≥450 milliliters (mL) of blood products within 28 days of the Day 1 Visit.
• Participant has participated in an interventional clinical study within 28 days prior to the day of enrollment or plans to do so while enrolled in this study.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

ModernaTX, Inc.

INDUSTRY

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Locations

Meridian Clinical Research (Sioux City, IA)

Sioux City, Iowa, United States

Johnson County Clin-Trials

Lenexa, Kansas, United States

Benchmark Research - Fort Worth

Fort Worth, Texas, United States

Clinical Research Puerto Rico, Inc.

Guayama, PR, Puerto Rico

Ponce Medical School Foundation, Inc.

Ponce, PR, Puerto Rico

Ponce Medical School Foundation, Inc.

Ponce, PR, Puerto Rico

Clinical Research Puerto Rico, Inc.

San Juan, PR, Puerto Rico

Latin Clinical Trial Center, Inc.

San Juan, PR, Puerto Rico

GCM Medical Group, PSC

San Juan, PR, Puerto Rico

Carribean Medical Research

San Juan, PR, Puerto Rico

University of Puerto Rico

San Juan, PR, Puerto Rico

Countries

United States; Puerto Rico

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Document Type: Informed Consent Form

View Document

Other Identifiers

HHSO100201600029C

Identifier Type: OTHER_GRANT

Identifier Source: secondary_id

mRNA-1893-P201

Identifier Type: -

Identifier Source: org_study_id