NCT05137236

A Study to Evaluate the Immunogenicity and Safety of mRNA-1283 COVID-19 Vaccine Boosters

A Phase 2A, Randomized, Stratified, Observer-Blind Study to Evaluate the Immunogenicity and Safety of mRNA-1283 Vaccine Boosters for SARS-CoV-2

• Status: Completed
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 540 (actual)
• Sponsor: ModernaTX, Inc. · Industry
• Sex: All
• Age: 18 Years
• Healthy volunteers: Accepted

Summary

The main goal of Part A of this study is to assess the safety, reactogenicity, and immunogenicity of the study vaccine candidates. The main goal of Part B of this study is to assess the safety, reactogenicity, and immunogenicity of the mRNA-1283.529 booster vaccine candidate.

Detailed description

Part A of this study will assess whether a single dose of mRNA-1283 at three different dose levels or mRNA-1283.211 at two different dose levels will boost antibody responses to the Wuhan-Hu-1 (ancestral strain of SARS-CoV-2) virus, and to the B.1.351 variant, and potentially other SARS-CoV-2 variants, and it will also be used to select a dose for subsequent clinical evaluation. The study will include an active comparator group of participants who will receive mRNA-1273. Participants in Part A who received the primary series of mRNA-1273 with appropriate documentation at least 6 months prior will be randomized 1:1:1:1:1:1 to receive a single boost of mRNA-1283 at one of three dose levels, a single boost of mRNA-1283.211 at one of two dose levels, or a single dose of the active comparator, mRNA-1273. Part B of this study will assess whether a single dose of mRNA-1283.529 at two different dose levels as the second booster after a first booster of mRNA- 1273, at least 3 months prior, will boost antibody response to the ancestral strain of the SARS-CoV-2 virus, the B.1.1.529 variant, and potentially other SARS-CoV-2 variants, and inform dose selection for mRNA-1283.529 booster vaccine candidate for subsequent clinical evaluation. Participants in Part B who received the primary series of mRNA 1273 and who received a first booster dose of mRNA-1273 at least 3 months prior will be enrolled in a 1:1 ratio to receive a single boost of mRNA 1283.529 at one of two dose levels.

Conditions

• SARS-CoV-2

Interventions

Type	Name	Description
BIOLOGICAL	mRNA-1283	Sterile liquid for injection
BIOLOGICAL	mRNA-1283.211	Sterile liquid for injection
BIOLOGICAL	mRNA-1273	Sterile liquid for injection
BIOLOGICAL	mRNA-1283.529	Sterile liquid for injection

Timeline

• Start date: 2021-12-06
• Primary completion: 2023-03-23
• Completion: 2023-03-23
• First posted: 2021-11-30
• Last updated: 2025-07-17
• Results posted: 2025-07-17

Locations

17 sites across 1 country: United States

Regulatory

• FDA-regulated drug study