NCT04649151

A Study to Evaluate the Safety, Reactogenicity, and Effectiveness of mRNA-1273 Vaccine in Adolescents 12 to <18 Years Old to Prevent COVID-19

A Phase 2/3, Randomized, Observer-Blind, Placebo-Controlled Study to Evaluate the Safety, Reactogenicity, and Effectiveness of mRNA-1273 SARS-CoV-2 Vaccine in Healthy Adolescents 12 to <18 Years of Age

• Status: Completed
• Phase: Phase 2 / Phase 3
• Study type: Interventional
• Enrollment: 4,328 (actual)
• Sponsor: ModernaTX, Inc. · Industry
• Sex: All
• Age: 12 Years – 18 Years
• Healthy volunteers: Accepted

Summary

The mRNA-1273 vaccine is being developed to prevent COVID-19, the disease resulting from Severe Acute Respiratory Syndrome coronavirus (SARS-CoV-2) infection. The study is designed to primarily evaluate the safety, reactogenicity, and effectiveness of mRNA-1273 vaccine administered as primary series and a booster dose (BD) to an adolescent population. The study will also evaluate the safety and immunogenicity of an mRNA-1273.222 vaccine against the SARS-CoV- 2 omicron variant as a primary series.

Detailed description

This is a Phase 2/3 study, with Part 1A (Blinded Phase), Part 1B (Open-label Observational Phase), Part 1C (Booster Dose \[BD\] Phase), which consists of Part 1C-1 and Part 1C-2, Part 2 (Open-Label), and Part 3 (Open-label). Participants in Part 1A are blinded to their treatment assignment, with participants receiving either 2 active mRNA-1273 vaccine doses or placebo. Part 1B of the study is designed to offer participants whose age group becomes Emergency Use Authorization (EUA) eligible to be unblinded so that participants who received placebo in Part 1A can request 2 doses of open-label mRNA-1273 vaccine. Part 1C-1 of the study will offer participants in Part 1A and Part 1B who are at least 5 months from the last dose, the option to request a homologous BD of mRNA-1273. Part 1C-2 is designed to provide a heterologous BD of mRNA-1273 to eligible participants who completed primary COVID-19 vaccination series with a non-Moderna vaccine under EUA and are at least 3 months from the last dose. Part 2 is an open-label design. Participants will receive 2 doses and may receive a booster dose of mRNA-1273 SARS-CoV-2 vaccine. Part 3 is an open-label design. Participants will receive up to 2 doses of mRNA-1273.222 vaccine. Please access http://TeenCoveStudy.com for additional information, such as Study Overview, Participation, Site Locations along with contact numbers for each location for the study.

Conditions

• SARS-CoV-2

Interventions

Type	Name	Description
BIOLOGICAL	mRNA-1273	Sterile liquid for injection
BIOLOGICAL	Placebo	0.9% sodium chloride (normal saline) injection
BIOLOGICAL	mRNA-1273.222	Sterile solution for injection

Timeline

• Start date: 2020-12-09
• Primary completion: 2024-06-14
• Completion: 2024-06-14
• First posted: 2020-12-02
• Last updated: 2025-09-15
• Results posted: 2025-09-15

Locations

53 sites across 2 countries: United States, Dominican Republic

Regulatory

• FDA-regulated drug study