SARS-CoV-2Phase 2/3TeenCoveNCT04649151
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 study testing mRNA-1273 and mRNA-1273.222 in people with SARS-CoV-2, run by ModernaTX, Inc. at 53 sites in 2 countries.
Trial 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… Read more about this study
- Who is it for?
- Ages 12 to 18 yearsHealthy volunteers can take part
- Conditions the study is for
- SARS-CoV-2
- What is being tested?
- mRNA-1273 and mRNA-1273.222
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 4,328 participants
- Where
- 53 sitesin 2 countries
- Study dates
- 9 Dec 2020to 14 Jun 2024
- Phase
- Phase 2/3
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 12 to 18 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- For Part 1A, Part 2 and Part 3:
- Participants 12 to <18 years of age at the time of consent (Screening Visit, Day 0) who, in the opinion of the Investigator, are in good general health based on review of medical history and screening physical examination.
- Investigator assessment that the participant, in the case of an emancipated minor, or parent(s)/legally acceptable representative(s) (LAR[s]) understand and is willing and physically able to comply with protocol-mandated follow up, including all procedures and provides written informed consent/assent.
- Body mass index (BMI) at or above the third percentile according to World Health Organization (WHO) Child Growth Standards at the Screening Visit (Day 0)
- Female participants of nonchildbearing potential may be enrolled in the study. Nonchildbearing potential is defined as premenarche or surgically sterile (history of bilateral tubal ligation, bilateral oophorectomy, hysterectomy).
- Female participants of childbearing potential may be enrolled in the study if the participant has a negative pregnancy test at Screening (Day 0), on the day of the first injection (Day 1), on the day of the second injection (Day 29 in Parts 1A and Part 2, and Day 181 in Part 3); has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first injection (Day 1); and has agreed to continue adequate contraception or abstinence through 3 months following the second injection (Day 29 in Part 1A and Part 2, and Day 181 in Part 3).
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- For Part 1B:
- Participants must have been previously enrolled in mRNA-1273-P203 study.
- Female participants of childbearing potential may be enrolled in the study if the participant has a negative pregnancy test on the day of the first injection (Open-Label-Day 1) and on the day of the second injection (Open-Label-Day 29).
- For Part 1C-1 Homologous Booster Dose:
- Participants must have been previously enrolled in the mRNA-1273-P203 study, are actively participating in Part 1A or Part 1B and are least 5 months from the last dose.
- Female participants of childbearing potential may be enrolled in the study if the participant has a negative pregnancy test on the day of the first injection (BD-Day 1).
- Part 1C-2 Heterologous Booster Dose:
- Male or female, 12 to < 18 years of age at the time of consent who, in the opinion of the investigator, is in good general health based on review of medical history and screening physical examination AND has completed non-Moderna primary COVID-19 vaccination series under EUA (for example, Pfizer) at least 3 months from consent.
Who cannot join
- For Part 1A, Part 2, and Part 3:
- Has a known history of SARS-CoV-2 infection within 2 weeks prior to administration of investigational product (IP) or known close contact with anyone with laboratory-confirmed SARS-CoV-2 infection of COVID-19 within 2 weeks prior to administration of IP (Part 2 participants only). For Part 3 participants, known history of SARS-CoV-2 infection within 90 days prior to administration of IP or known close contact with anyone with laboratory-confirmed SARS-CoV-2 infection or COVID-19 within 90 days prior to administration of IP.
- Travel outside of the United States or home country (Part 2 and Part 3 only) in the 28 days prior to the Screening Visit (Day 0).
- Pregnant or breastfeeding
- Is acutely ill or febrile 24 hours prior to or at the Screening Visit (Day 0). Fever is defined as a body temperature ≥38.0°Celsius (C)/≥100.4°Farenheit (F). Participants who meet this criterion may have visits rescheduled within the relevant study visit windows. Afebrile participants with minor illnesses can be enrolled at the discretion of the Investigator.
- Prior administration of an investigational coronavirus (for example, SARS-CoV-2, SARS-CoV, Middle East Respiratory Syndrome [MERS-CoV]) vaccine
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- Current treatment with investigational agents for prophylaxis against COVID-19
- Has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation, or that could interfere with safety assessments or interpretation of results according to the Investigator's judgment
- Current use of any inhaled substance (for example, tobacco or cannabis smoke, nicotine vapors)
- History of chronic smoking (≥1 cigarette a day) within 1 year of the Screening Visit (Day 0)
- History of illegal substance use or alcohol abuse within the past 2 years. This exclusion does not apply to historical cannabis use that was formerly illegal in the participant's state but is legal at the time of screening.
- History of a diagnosis or condition that, in the judgment of the Investigator, may affect study endpoint assessment or compromise participant safety, specifically:
- Congenital or acquired immunodeficiency, including human immunodeficiency virus (HIV) infection
- Suspected active hepatitis
- Has a bleeding disorder that is considered a contraindication to IM injection or phlebotomy
- Dermatologic conditions that could affect local solicited AR assessments
- History of anaphylaxis, urticaria, or other significant AR requiring medical intervention after receipt of a vaccine
- Diagnosis of malignancy within the previous 10 years (excluding nonmelanoma skin cancer)
- Febrile seizures
- Receipt of:
- Any licensed vaccine within 28 days before the first dose of IP or plans for receipt of any licensed vaccine within 28 days before and/or after each dose of IP.
- Systemic immunosuppressants or immune-modifying drugs for >14 days in total within 6 months prior to the day of enrollment (for corticosteroids, ≥20 mg/day prednisone equivalent). Topical tacrolimus is allowed if not used within 14 days prior to the day of enrollment. Participants may have visits rescheduled for enrollment if they no longer meet this criterion within the Screening Visit window. Inhaled, nasal, and topical steroids are allowed.
- Intravenous blood products (red cells, platelets, immunoglobulins) within 3 months prior to enrollment
- Has donated ≥450 milliliters (mL) of blood products within 28 days prior to the Screening Visit (Day 0) or plans to donate blood products during the study
- Participated in an interventional clinical study within 28 days prior to the Screening Visit (Day 0) or plans to do so while participating in this study
- Is an immediate family member or has a household contact who is an employee of the research center or otherwise involved with the conduct of the study
- For Part 1C-1 and Part 1C-2:
- Pregnant or breastfeeding.
- Is acutely ill or febrile 24 hours prior to or at the Screening Visit (Day 0). Fever is defined as a body temperature ≥ 38.0°C/≥ 100.4°F. Participants who meet this criterion may have visits rescheduled within the relevant study visit windows. Afebrile participants with minor illnesses can be enrolled at the discretion of the investigator.
- Has a medical, psychiatric, or occupational condition that may pose additional risk as a result of participation, or that could interfere with safety assessments or interpretation of results according to the investigator's judgment.
- History of a diagnosis or condition (after enrolment in Part 1A) that, in the judgment of the investigator, may affect study endpoint assessment or compromise participant safety:
- Suspected active hepatitis
- Has a bleeding disorder that is considered a contraindication to IM injection or phlebotomy
- Dermatologic conditions that could affect local solicited AR assessments
- History of anaphylaxis, urticaria, or other significant AR requiring medical intervention after receipt of a vaccine
- Diagnosis of malignancy (excluding nonmelanoma skin cancer)
- Receipt of:
- Any authorized or licensed vaccine within 28 days before the first dose of IP or plans for receipt of any licensed vaccine through 28 days following the last dose of IP or any seasonal influenza vaccine within 14 days before the first dose of IP or plans for receipt of any seasonal influenza vaccine 14 days following the last dose of IP.
- Participated in an interventional clinical study, other than mRNA-1273-P203 study, within 28 days prior to the Screening Visit (Day 0 [for Part 1C-1], BD-Day 0 [for Part 1C-2]) or plans to do so while participating in this study.
- Part 1C-2 Heterologous Booster Dose:
- Has a known history of SARS-CoV-2 infection within 2 weeks prior to administration of IP or known close contact with anyone with laboratory-confirmed SARS-CoV-2 infection or COVID 19 within 2 weeks prior to administration of IP.
Trial locations and contacts
53 sites in 2 countries.
53 sites in 2 countries
United States48 sites
Velocity Clinical Research - Albuquerque - PPDS
Albuquerque, New Mexico, 87102
Benchmark Research
Austin, Texas, 78705
Velocity Clinical Research - Banning
Banning, California, 92220
Cope Family Medicine - Ogden Clinic - CCT
Bountiful, Utah, 84010
Tekton Research - Georgia - PPDS
Chamblee, Georgia, 30341
Coastal Pediatric Associates
Charleston, South Carolina, 29414
Meridian Clinical Research - Charleston, SC
Charleston, South Carolina, 29414
Olivo Medical and Wellness Center
Chicago, Illinois, 60618
Velocity Clinical Research - Cincinnati - PPDS
Cincinnati, Ohio, 45242
IACT Health - Roswell - IACT - HyperCore - PPDS
Columbus, Georgia, 31904
Coastal Bend Research Center
Corpus Christi, Texas, 78404
Velocity Clinical Research - Providence - PPDS
East Greenwich, Rhode Island, 02818
Child Healthcare Associates - East Syracuse
East Syracuse, New York, 13210
Alliance for Multispecialty Research -El Dorado
El Dorado, Kansas, 67042
Meridian Clinical Research (Endwell-New York) - Platinum - PPDS
Endwell, New York, 13901
ACRC Trials
Frisco, Texas, 75033
Cyn3rgy Research - ClinEdge - PPDS
Gresham, Oregon, 97030
Velocity Clinical Research - Gulfport - PPDS
Gulfport, Mississippi, 39503
Meridian Clinical Research (Hastings-Nebraska) - Platinum - PPDS
Hastings, Nebraska, 68901
DM Clinical Research - Kool Kids Pediatrics - ERN - PPDS
Houston, Texas, 77064
Wee Care Pediatrics - Kaysville
Kaysville, Utah, 84037
Paradigm Clinical Research
La Mesa, California, 91942
Altus Research - Hunt - PPDS
Lake Worth, Florida, 33461
Johnson County Clin-Trials
Lenexa, Kansas, 66219
Meridian Clinical Research - (Macon Georgia) - Platinum - PPDS
Macon, Georgia, 31210
Velocity Clinical Research - Boise - PPDS
Meridian, Idaho, 83642
Velocity Clinical Research - Metairie - PPDS
Metairie, Louisiana, 70006
Clinical Research Institute, Inc - CRN - PPDS
Minneapolis, Minnesota, 55402
Cottonwood Pediatrics
Murray, Utah, 84107
Meridian Clinical Research (Norfolk, Virginia)
Norfolk, Virginia, 68701
Coastal Carolina Research Center
North Charleston, South Carolina, 29405
Lynn Health Science Institute
Oklahoma City, Oklahoma, 73112
Quality Clinical Research - HyperCore - PPDS
Omaha, Nebraska, 68114
Meridian Clinical Research (Omaha-Nebraska) - Platinum - PPDS
Omaha, Nebraska, 68134
Accel Research Sites - Nona Pediatric Center - ERN - PPDS
Orlando, Florida, 32829
Meridian Clinical Research - Family Practice Ports - Portsmouth - Platinum - PPDS
Portsmouth, Virginia, 23703
Clinical Trials of Texas, Inc. - PPDS
San Antonio, Texas, 78229
Tekton Research
San Antonio, Texas, 78229
Tekton Research
San Antonio, Texas, 78244
Meridian Clinical Research (Sioux City - Iowa)
Sioux City, Iowa, 51106
South Ogden Family Medicine/Ogden Clinic - CCT Research
South Ogden, Utah, 84405
Sundance Clinical Research - Platinum - PPDS
St Louis, Missouri, 63141
Clinical Research Atlanta
Stockbridge, Georgia, 30281
Alliance for Multispecialty Research
Syracuse, Utah, 84075
Vital Prospects Clinical Research Institute PC - CRN - PPDS
Tulsa, Oklahoma, 74136
Velocity Clinical Research - Valparaiso
Valparaiso, Indiana, 46383
Advanced Clinical Research - Jordan Valley - ERN - PPDS
West Jordan, Utah, 84088
University of Massachusetts Medical School, Molecu
Worcester, Massachusetts, 01655
Dominican Republic5 sites
Caimed Dominicana S.A.S
Santo Domingo, Nacional
Hospital General Regional Dr. Marcelino Velez Santana
Santo Domingo, Nacional
Hospital Materno Infantil San Lorenzo de Los Mina
Santo Domingo, Nacional
Instituto Dermatologico y Cirugia de la Piel Dr. H Sede San Cristóbal
Santo Domingo, Nacional
Instituto Dominicano de Estudios Virologicos IDEV
Santo Domingo, Nacional
About this study
Official title: 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
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.
Read the 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
- Being tested
- mRNA-1273, Placebo, mRNA-1273.222
- Keywords
- mRNA-1273, mRNA-1273 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, mRNA-1273.222 vaccine, SARS-CoV-2 VOC, SARS-CoV-2 VOC vaccine, Omicron, Variant, Coronavirus, Virus Diseases, Messenger RNA, COVID-19, COVID-19 Vaccine, Moderna
- Medical subject headings
- Coronavirus Infections, Virus Diseases, COVID-19
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
mRNA-1273Biological
Sterile liquid for injection
PlaceboBiological
0.9% sodium chloride (normal saline) injection
mRNA-1273.222Biological
Sterile solution for injection
| Study group | Role | What they receive |
|---|---|---|
| mRNA-1273 | Experimental | Part 1A (Blinded Phase): Participants will receive 2 intramuscular (IM) injections of mRNA-1273 (100 microgram [ug] each), 28 days apart, on Day 1 and Day 29.
Part 1B (Open-Label Phase): Participants who cross over from placebo in Part 1A to Part 1B will receive 2 IM injections of mRNA-1273 (100 ug each), 28 days apart on Open Label Day 1 and Open Label Day 29.
Part 2 (Open-Label): Participants will receive 2 IM injections of mRNA-1273 (50 ug each), 28 days apart, on Day 1 and Day 29 and may receive a booster dose on Day 149. Receives: Biological: mRNA-1273 |
| Placebo | Placebo comparator | Part 1A (Blinded Phase): Participants will receive 2 IM injections of mRNA-1273 matching placebo, 28 days apart, on Day 1 and Day 29. Receives: Biological: Placebo |
| mRNA-1273 BD | Experimental | Part 1C-1 (BD Phase): Participants will receive 1 IM injection of mRNA-1273 (50 ug) on BD-Day 1, 5 months after the last dose of Part 1A and 1B.
Part 1C-2 (BD Phase): Participants will receive 1 IM injection of mRNA-1273 (50 ug) on BD-Day 1, at least 3 months post-last dose. Receives: Biological: mRNA-1273 |
| mRNA-1273.222 | Experimental | Part 3 (Open-Label): Participants will receive up to 2 IM injections of mRNA-1273.222 (50 ug each), 6 months apart, on Day 1 and Day 181. Receives: Biological: mRNA-1273.222 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)
Solicited ARs (local and systemic) were collected in an electronic diary (eDiary). Local ARs included injection site pain, injection site erythema (redness), injection site swelling/induration (hardness), and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs included fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Solicited ARs considered causally related to injection were graded 1-4 (per Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials); lower score indicated lower severity, and higher score indicated greater severity. Investigator reviewed if the solicited AR was recorded as an adverse event (AE) as detailed in the AE section. A Summary of serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is located in the AE section.
Measured: 7 days post-vaccination
Number of Participants With Unsolicited AEs
An unsolicited AE was any AE reported by the participant that was not specified as a solicited AR in the protocol or was specified as a solicited AR but started outside the protocol-defined period for reporting solicited ARs (onset after Day 7 of dosing). An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result or other safety assessment, including one that worsened from baseline and was considered clinically significant by the Investigator was recorded as an AE.
Non-serious SARs persisting beyond 7 days, leading to discontinuation, or medically attended were classified as AEs in Part 1/2 but not in Part 3. COVID-19/SARS-CoV-2 infections were AEs in Part1/2 but were considered clinical events for efficacy in Part 3 and not AEs.
A Summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the AE section.
Measured: Up to 28 days post-vaccination
Part 1A Geometric Mean Value of Serum Pseudovirus Neutralizing Antibody (nAb) ID50 Titers From Study P203 Vaccine Recipients at Day 57 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Pseudovirus nAb ID50 titers were measured using pseudovirus neutralization assay (PsVNA) assay. Antibody values reported as below the lower limit of quantification (LLOQ) were replaced by 0.5*LLOQ. Values greater than the upper limit of quantification (ULOQ) were replaced by the ULOQ if actual values were not available (LLOQ: 18.5 arbitrary units (AU)/milliliter (mL), ULOQ: 45118 AU/mL). Antibody levels were analyzed using an analysis of covariance (ANCOVA) model with the group variable (adolescents in P203 and young adults in P301) as fixed effect. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria were used for comparison assessments of immune response.
Measured: Day 57 Study P203/Day 57 Study P301
Part 1A Seroresponse Rate (SRR) for Serum Pseudovirus nAb ID50 in Study P203 Vaccine Recipients at Day 57 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Percentage of participants with seroresponse for pseudovirus nAb ID50 measured using PsVNA assay are reported. Seroresponse was defined as a change from below the LLOQ to equal above 4*LLOQ, or at least a 4-fold rise if baseline is equal to or above the LLOQ (LLOQ: 18.5 AU/mL), ULOQ: 45118 AU/mL).
PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria were used for comparison assessments of immune response.
Measured: Day 57 Study P203/Day 57 Study P301
Part 1C-1 Geometric Mean Concentration (GMC) of Serum Pseudovirus nAb Against the Original Strain After the BD in Study P203 at BD Day 29 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Pseudovirus nAb were measured using PsVNA assay. Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10, ULOQ: 281600). PPIS P301: randomly selected participants from study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison assessments of immune response.
Measured: BD Day 29 Study P203/Day 57 Study P301
Part 1C-1 SRR of Serum Pseudovirus nAb Against the Original Strain After the BD in Study P203 at BD Day 29 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Percentage of participants with seroresponse for pseudovirus nAb measured using PsVNA assay are reported. Seroresponse relative to pre-Dose 1 (baseline) at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold-rise if baseline was equal to or above LLOQ (LLOQ: 10 AU/mL, ULOQ: 281600 AU/mL). PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison assessments of immune response.
Measured: BD Day 29 Study P203/Day 57 Study P301
Part 3 GMC of nAb Post Dose 1 mRNA 1273.222 Against Omicron BA.4/BA.5 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 103 AU/mL, ULOQ: 28571 AU/mL). ANCOVA model with the group variable (adolescents in P203 and young adults in P301) as fixed effect. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison of immune response.
Measured: Day 29 Study P203/Day 57 Study P301
Part 1C-2 GMC of Post-booster Pseudovirus nAb Against Ancestral Strain at BD Day 29
Antibody values reported as below the LLOQ were replaced by 0.5 * LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL).
Measured: BD Day 29
Part 2 GMC of the Pseudovirus nAb Against Ancestral Strain at Day 57
Antibody values reported as below the LLOQ were replaced by 0.5 * LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL).
Measured: Day 57
Part 3 GMC of nAb Post Dose 1 mRNA 1273.222 Against SARS-CoV-2 Ancestral Strain Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL). ANCOVA model with the group variable (adolescents in P203 and young adults in P301) as fixed effect. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison of immune response.
Measured: Day 29 Study P203/Day 57 Study P301
Part 2 SRR of Pseudovirus nAb Against Ancestral Strain
Percentage of participants with seroresponse for pseudovirus nAb measured using PsVNA assay are reported. Seroresponse relative to pre-Dose 1 (baseline) at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold-rise if baseline was equal to or above the LLOQ (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL).
Measured: Day 57
Number of Participants With SAEs, AEs of Special Interest (AESIs), Medically Attended AEs (MAAEs), and AEs Leading to Study Discontinuation
SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability/permanent damage, was a congenital anomaly/birth defect, or was an important medical event. AESIs were identified based upon medical concepts that may be related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance. MAAE was an AE that led to an unscheduled visit to a healthcare practitioner, included visits to a study site for unscheduled assessments (for example, abnormal laboratory follow-up, and visits to healthcare practitioners external to the study site [for example, urgent care, primary care physician]). Non-serious SARs persisting beyond 7 days, leading to discontinuation, or medically attended were defined as AEs in Part 1/2 but not in Part 3. COVID-19/SARS-CoV-2 infections were AEs in Part 1/2 but were considered clinical events for efficacy in Part 3 and not AEs.
Measured: Day 1 up to Day 751
Secondary outcomes (13)
Part 1A Number of Participants With a SARS-CoV-2 Infection (Symptomatic or Asymptomatic)
SARS-CoV-2 infection was defined in participants with negative SARS-CoV-2 status at baseline: bAb level against SARS-CoV-2 nucleocapsid protein negative at Day 1, that became positive postbaseline; or positive postbaseline.
Measured: Day 43 (14 days after second injection) up to a median follow up of 2.5 months after second injection
Part 1A Number of Participants With Asymptomatic SARS-CoV-2 Infection
Asymptomatic SARS-CoV-2 infection was defined as absence of symptoms and a positive RT-PCR or serology test (bAb levels against SARS-CoV-2 nucleocapsid protein) post dosing in participants who did not have an infection at baseline or pre-Dose 1.
Measured: Day 43 (14 days after second injection) up to a median follow up of 2.5 months after second injection
Part 1A Number of Participants With a First Occurrence of Symptomatic COVID-19
COVID-19 was defined as symptomatic disease based on the following criteria: participants experienced at least 2 of the following systemic symptoms: fever (≥ 38ºC/≥ 100.4ºF), chills, myalgia, headache, sore throat, new olfactory and taste disorder(s); or experienced at least 1 of the following respiratory signs/symptoms: cough, shortness of breath or difficulty breathing, or clinical or radiographical evidence of pneumonia; and had at least 1 nasopharyngeal swab, nasal swab, or saliva sample (or respiratory sample, if hospitalized) positive for SARS-CoV-2.
Measured: Day 43 (14 days after second injection) up to 2.5 months after second injection
Part 1A Number of Participants With Secondary Case Definition of COVID-19 (Center for Disease Control and Prevention [CDC] Case Definition)
Secondary case definition of COVID-19 was defined by the following criteria: 1 systemic or respiratory symptoms: fever (temperature > 38ºC/≥ 100.4ºF), or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle aches, or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea, or vomiting or diarrhea, and at least one positive test for SARS-CoV-2.
Measured: Day 43 (14 days after second injection) up to a median follow up of 2.5 months after second injection
Part 1C-1 SRR of the Post-booster Serum Binding Antibody (bAb) Against Variants of Interest (B.1.1.7, B.1.351, B.1.617.2, and P.1) as Measured by MSD
Percentage of participants with seroresponse for bAb measured using (MesoScale Discovery) MSD are reported. Seroresponse from baseline (pre-Dose 1) at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold-rise if baseline (pre-Dose 1) is equal to or above the LLOQ.
Measured: BD Day 29
Part 1C-1 GMC of Post-booster Pseudovirus nAb Against Variant Strain (B.1.1.529)
Post-booster Pseudovirus nAb against B.1.1.529 (LLOQ: 8 AU/mL, ULOQ: 24503 AU/mL). Antibody values reported as below the LLOQ were replaced by 0.5 * LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available.
Measured: BD Day 29
Part 3 SRR of Serum Pseudovirus nAb Post Dose 1 of mRNA-1273.222 Against Omicron BA.4/BA.5 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Seroresponse from pre Dose 1 Baseline at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold rise if Baseline was equal to or above the LLOQ (LLOQ: 103 AU/mL, ULOQ:
28571 AU/mL). PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison of immune response.
Measured: Day 29 Study P203/Day 57 Study P301
Part 3 Pseudovirus nAb SRR of Post Dose 1 of mRNA-1273.222 Against Ancestral Strain Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Percentage of participants with seroresponse for pseudovirus nAb measured using PsVNA assay are reported. Seroresponse from pre Dose 1 Baseline at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold rise if Baseline was equal to or above the LLOQ. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison assessments of immune response.
Measured: Day 29 P203/Day 57 P301
Part 3 GM Value of Post Dose 1 (Day 29) of mRNA-1273.222 bAb Against Other Variants of Interest
mRNA-1273.222 bAb was measured using a S-binding IgG immunoassay. Antibody values reported as below the LLOQ were replaced by 0.5 * LLOQ. Values greater than the ULOQ are replaced by the ULOQ if actual values are not available (LLOQ: 397 AU/ml, ULOQ: 2200000 AU/mL).
Measured: Day 29
Part 1C-2 GM Value of mRNA-1273 Booster Against Variants of Interest at Day 29
Measured: Day 29
Part 1A GM Level of SARS-CoV-2 Spike Protein-specific bAb at Days 1, 57, 209, 394
SARS-CoV-2 Spike Protein-specific bAb were measured using MSD electrochemiluminescence multiplex assay. Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ are replaced by the ULOQ if actual values are not available (LLOQ: 69 AU/mL, ULOQ: 14400000 AU/mL).
Measured: Days 1, 57, 209, 394
Part 1A GM Value of SARS-CoV-2-Specific nAb at Days 1, 57, 209, 394
SARS-CoV-2-Specific nAb were measured using PsVNA assay. Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ are replaced by the ULOQ if actual values are not available (LLOQ: 10 AU/mL, ULOQ: 281600 AU/mL).
Measured: Days 1, 57, 209, 394
Part 1C-1 GM Value of Post-booster Dose Serum bAb Against Variants of Interest (B.1.1.7, B.1.351, B.1.617.2, and P.1) as Measured by MSD
Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available. B.1.1.7 (LLOQ: 52, ULOQ: 8800000), B.1.351 (LLOQ: 111, ULOQ: 5000000), B.1.617.2 (LLOQ: 49, ULOQ: 7400000), P.1 (LLOQ: 143, ULOQ: 5800000).
Measured: BD Day 29
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Dec 2020
- Study start9 Dec 2020
- Primary completion14 Jun 2024
- Study completion14 Jun 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for SARS-CoV-2Studies of the same condition, open and under way.
- More trials run by ModernaTX, Inc.The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2/3
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 4,328 participants (actual)
Sponsor and investigators
- Lead sponsor
- ModernaTX, Inc.
- Sponsor type
- Industry (pharma, biotech, devices)
- Collaborators
- Biomedical Advanced Research and Development Authority
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04649151
- Sponsor's protocol ID
- mRNA-1273-P203
- Other IDs
- 2023-000382-14, 2023
- Acronym
- TeenCove
- Status last verified
- Aug 2025
- First submitted
- 30 Nov 2020
- Last updated
- 15 Sep 2025
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Figueroa AL, Torres D, Reyes-Acuna C, Matherne P, Yeakey A, Deng W, Xu W, Sigal Y, Chambers G, Olsen M, Girard B, Miller JM, Das R, Priddy F. Safety and immunogenicity of a single-dose omicron-containing COVID-19 vaccination in adolescents: an open-label, single-arm, phase 2/3 trial. Lancet Infect Dis. 2025 Feb;25(2):208-217. doi: 10.1016/S1473-3099(24)00501-2. Epub 2024 Sep 24.
PubMed 39332418Ali K, Berman G, Zhou H, Deng W, Faughnan V, Coronado-Voges M, Ding B, Dooley J, Girard B, Hillebrand W, Pajon R, Miller JM, Leav B, McPhee R. Evaluation of mRNA-1273 SARS-CoV-2 Vaccine in Adolescents. N Engl J Med. 2021 Dec 9;385(24):2241-2251. doi: 10.1056/NEJMoa2109522. Epub 2021 Aug 11.
PubMed 34379915
Study at a glance
From the registry record, last updated by the sponsor on 15 Sep 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT04649151
- Acronym / sponsor ID
- TeenCove / mRNA-1273-P203
- Conditions
- SARS-CoV-2
- Keywords
- mRNA-1273, mRNA-1273 vaccine, SARS-CoV-2, SARS-CoV-2 Vaccine, mRNA-1273.222 vaccine, SARS-CoV-2 VOC, SARS-CoV-2 VOC vaccine, Omicron
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 4,328 participants (actual)
- Lead sponsor
- ModernaTX, Inc.Industry (pharma, biotech, devices)
- Collaborators
- Biomedical Advanced Research and Development Authority
- Study start
- 9 Dec 2020 (actual)
- Primary completion
- 14 Jun 2024 (actual)
- Study completion
- 14 Jun 2024 (actual)
- First posted
- 2 Dec 2020 (actual)
- Results
- Posted 15 Sep 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 4
| Arm | Type | Receives |
|---|---|---|
| mRNA-1273 | Experimental | Biological: mRNA-1273Part 1A (Blinded Phase): Participants will receive 2 intramuscular (IM) injections of mRNA-1273 (100 microgram [ug] each), 28 days apart, on Day 1 and Day 29. Part 1B (Open-Label Phase): Participants who cross over from placebo in Part 1A to Part 1B will receive 2 IM injections of mRNA-1273 (100 ug each), 28 days apart on Open Label Day 1 and Open Label Day 29. Part 2 (Open-Label): Participants will receive 2 IM injections of mRNA-1273 (50 ug each), 28 days apart, on Day 1 and Day 29 and may receive a booster dose on Day 149. |
| Placebo | Placebo comparator | Biological: PlaceboPart 1A (Blinded Phase): Participants will receive 2 IM injections of mRNA-1273 matching placebo, 28 days apart, on Day 1 and Day 29. |
| mRNA-1273 BD | Experimental | Biological: mRNA-1273Part 1C-1 (BD Phase): Participants will receive 1 IM injection of mRNA-1273 (50 ug) on BD-Day 1, 5 months after the last dose of Part 1A and 1B. Part 1C-2 (BD Phase): Participants will receive 1 IM injection of mRNA-1273 (50 ug) on BD-Day 1, at least 3 months post-last dose. |
| mRNA-1273.222 | Experimental | Biological: mRNA-1273.222Part 3 (Open-Label): Participants will receive up to 2 IM injections of mRNA-1273.222 (50 ug each), 6 months apart, on Day 1 and Day 181. |
Who may qualify
- Ages
- 12 to 18 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (14 listed)
- Participants 12 to <18 years of age at the time of consent (Screening Visit, Day 0) who, in the opinion of the Investigator, are in good general health based on review of medical history and screening physical examination.
- Investigator assessment that the participant, in the case of an emancipated minor, or parent(s)/legally acceptable representative(s) (LAR[s]) understand and is willing and physically able to comply with protocol-mandated follow up, including all procedures and provides written informed consent/assent.
- Body mass index (BMI) at or above the third percentile according to World Health Organization (WHO) Child Growth Standards at the Screening Visit (Day 0)
- Female participants of nonchildbearing potential may be enrolled in the study. Nonchildbearing potential is defined as premenarche or surgically sterile (history of bilateral tubal ligation, bilateral oophorectomy, hysterectomy).
- Female participants of childbearing potential may be enrolled in the study if the participant has a negative pregnancy test at Screening (Day 0), on the day of the first injection (Day 1), on the day of the second injection (Day 29 in Parts 1A and Part 2, and Day 181 in Part 3); has practiced adequate contraception or has abstained from all activities that could result in pregnancy for at least 28 days prior to the first injection (Day 1); and has agreed to continue adequate contraception or abstinence through 3 months following the second injection (Day 29 in Part 1A and Part 2, and Day 181 in Part 3).
Key exclusion criteria (41 listed)
- Has a known history of SARS-CoV-2 infection within 2 weeks prior to administration of investigational product (IP) or known close contact with anyone with laboratory-confirmed SARS-CoV-2 infection of COVID-19 within 2 weeks prior to administration of IP (Part 2 participants only). For Part 3 participants, known history of SARS-CoV-2 infection within 90 days prior to administration of IP or known close contact with anyone with laboratory-confirmed SARS-CoV-2 infection or COVID-19 within 90 days prior to administration of IP.
- Travel outside of the United States or home country (Part 2 and Part 3 only) in the 28 days prior to the Screening Visit (Day 0).
- Pregnant or breastfeeding
- Is acutely ill or febrile 24 hours prior to or at the Screening Visit (Day 0). Fever is defined as a body temperature ≥38.0°Celsius (C)/≥100.4°Farenheit (F). Participants who meet this criterion may have visits rescheduled within the relevant study visit windows. Afebrile participants with minor illnesses can be enrolled at the discretion of the Investigator.
- Prior administration of an investigational coronavirus (for example, SARS-CoV-2, SARS-CoV, Middle East Respiratory Syndrome [MERS-CoV]) vaccine
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| mRNA-1273Sterile liquid for injection | Biological | mRNA-1273, mRNA-1273 BD |
| Placebo0.9% sodium chloride (normal saline) injection | Biological | Placebo |
| mRNA-1273.222Sterile solution for injection | Biological | mRNA-1273.222 |
Primary outcome
Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs)
Time frame: 7 days post-vaccination
Solicited ARs (local and systemic) were collected in an electronic diary (eDiary). Local ARs included injection site pain, injection site erythema (redness), injection site swelling/induration (hardness), and axillary (underarm) swelling or tenderness ipsilateral to the side of injection. Systemic ARs included fever, headache, fatigue, myalgia, arthralgia, nausea/vomiting, and chills. Solicited ARs considered causally related to injection were graded 1-4 (per Toxicity Grading Scale for Healthy Adult and Adolescent Volunteers Enrolled in Preventive Vaccine Clinical Trials); lower score indicated lower severity, and higher score indicated greater severity. Investigator reviewed if the solicited AR was recorded as an adverse event (AE) as detailed in the AE section. A Summary of serious AEs (SAEs) and nonserious AEs ("Other"), regardless of causality, is located in the AE section.
Number of Participants With Unsolicited AEs
Time frame: Up to 28 days post-vaccination
An unsolicited AE was any AE reported by the participant that was not specified as a solicited AR in the protocol or was specified as a solicited AR but started outside the protocol-defined period for reporting solicited ARs (onset after Day 7 of dosing). An AE was defined as any untoward medical occurrence associated with the use of a drug in humans, whether or not considered drug related. Any abnormal laboratory test result or other safety assessment, including one that worsened from baseline and was considered clinically significant by the Investigator was recorded as an AE. Non-serious SARs persisting beyond 7 days, leading to discontinuation, or medically attended were classified as AEs in Part 1/2 but not in Part 3. COVID-19/SARS-CoV-2 infections were AEs in Part1/2 but were considered clinical events for efficacy in Part 3 and not AEs. A Summary of SAEs and nonserious AEs ("Other"), regardless of causality, is located in the AE section.
Part 1A Geometric Mean Value of Serum Pseudovirus Neutralizing Antibody (nAb) ID50 Titers From Study P203 Vaccine Recipients at Day 57 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: Day 57 Study P203/Day 57 Study P301
Pseudovirus nAb ID50 titers were measured using pseudovirus neutralization assay (PsVNA) assay. Antibody values reported as below the lower limit of quantification (LLOQ) were replaced by 0.5*LLOQ. Values greater than the upper limit of quantification (ULOQ) were replaced by the ULOQ if actual values were not available (LLOQ: 18.5 arbitrary units (AU)/milliliter (mL), ULOQ: 45118 AU/mL). Antibody levels were analyzed using an analysis of covariance (ANCOVA) model with the group variable (adolescents in P203 and young adults in P301) as fixed effect. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria were used for comparison assessments of immune response.
Part 1A Seroresponse Rate (SRR) for Serum Pseudovirus nAb ID50 in Study P203 Vaccine Recipients at Day 57 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: Day 57 Study P203/Day 57 Study P301
Percentage of participants with seroresponse for pseudovirus nAb ID50 measured using PsVNA assay are reported. Seroresponse was defined as a change from below the LLOQ to equal above 4*LLOQ, or at least a 4-fold rise if baseline is equal to or above the LLOQ (LLOQ: 18.5 AU/mL), ULOQ: 45118 AU/mL). PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria were used for comparison assessments of immune response.
Part 1C-1 Geometric Mean Concentration (GMC) of Serum Pseudovirus nAb Against the Original Strain After the BD in Study P203 at BD Day 29 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: BD Day 29 Study P203/Day 57 Study P301
Pseudovirus nAb were measured using PsVNA assay. Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10, ULOQ: 281600). PPIS P301: randomly selected participants from study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison assessments of immune response.
Part 1C-1 SRR of Serum Pseudovirus nAb Against the Original Strain After the BD in Study P203 at BD Day 29 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: BD Day 29 Study P203/Day 57 Study P301
Percentage of participants with seroresponse for pseudovirus nAb measured using PsVNA assay are reported. Seroresponse relative to pre-Dose 1 (baseline) at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold-rise if baseline was equal to or above LLOQ (LLOQ: 10 AU/mL, ULOQ: 281600 AU/mL). PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison assessments of immune response.
Part 3 GMC of nAb Post Dose 1 mRNA 1273.222 Against Omicron BA.4/BA.5 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: Day 29 Study P203/Day 57 Study P301
Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 103 AU/mL, ULOQ: 28571 AU/mL). ANCOVA model with the group variable (adolescents in P203 and young adults in P301) as fixed effect. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison of immune response.
Part 1C-2 GMC of Post-booster Pseudovirus nAb Against Ancestral Strain at BD Day 29
Time frame: BD Day 29
Antibody values reported as below the LLOQ were replaced by 0.5 * LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL).
Part 2 GMC of the Pseudovirus nAb Against Ancestral Strain at Day 57
Time frame: Day 57
Antibody values reported as below the LLOQ were replaced by 0.5 * LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL).
Part 3 GMC of nAb Post Dose 1 mRNA 1273.222 Against SARS-CoV-2 Ancestral Strain Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: Day 29 Study P203/Day 57 Study P301
Antibody values reported as below the LLOQ were replaced by 0.5*LLOQ. Values greater than the ULOQ were replaced by the ULOQ if actual values were not available (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL). ANCOVA model with the group variable (adolescents in P203 and young adults in P301) as fixed effect. PPIS P301: randomly selected participants from Study P301 aged 18-25 meeting pre-specified criteria and SARS-CoV-2 negative were used for comparison of immune response.
Part 2 SRR of Pseudovirus nAb Against Ancestral Strain
Time frame: Day 57
Percentage of participants with seroresponse for pseudovirus nAb measured using PsVNA assay are reported. Seroresponse relative to pre-Dose 1 (baseline) at a participant level was defined as a change from below the LLOQ to equal or above 4 * LLOQ, or at least a 4-fold-rise if baseline was equal to or above the LLOQ (LLOQ: 10 AU/mL, ULOQ: 111433 AU/mL).
Number of Participants With SAEs, AEs of Special Interest (AESIs), Medically Attended AEs (MAAEs), and AEs Leading to Study Discontinuation
Time frame: Day 1 up to Day 751
SAE was defined as any AE that resulted in death, was life-threatening, required inpatient hospitalization or prolongation of existing hospitalization, resulted in disability/permanent damage, was a congenital anomaly/birth defect, or was an important medical event. AESIs were identified based upon medical concepts that may be related to COVID-19 or were of interest in COVID-19 vaccine safety surveillance. MAAE was an AE that led to an unscheduled visit to a healthcare practitioner, included visits to a study site for unscheduled assessments (for example, abnormal laboratory follow-up, and visits to healthcare practitioners external to the study site [for example, urgent care, primary care physician]). Non-serious SARs persisting beyond 7 days, leading to discontinuation, or medically attended were defined as AEs in Part 1/2 but not in Part 3. COVID-19/SARS-CoV-2 infections were AEs in Part 1/2 but were considered clinical events for efficacy in Part 3 and not AEs.
13 secondary outcomes
Part 1A Number of Participants With a SARS-CoV-2 Infection (Symptomatic or Asymptomatic)
Time frame: Day 43 (14 days after second injection) up to a median follow up of 2.5 months after second injection
Part 1A Number of Participants With Asymptomatic SARS-CoV-2 Infection
Time frame: Day 43 (14 days after second injection) up to a median follow up of 2.5 months after second injection
Part 1A Number of Participants With a First Occurrence of Symptomatic COVID-19
Time frame: Day 43 (14 days after second injection) up to 2.5 months after second injection
Part 1A Number of Participants With Secondary Case Definition of COVID-19 (Center for Disease Control and Prevention [CDC] Case Definition)
Time frame: Day 43 (14 days after second injection) up to a median follow up of 2.5 months after second injection
Part 1C-1 SRR of the Post-booster Serum Binding Antibody (bAb) Against Variants of Interest (B.1.1.7, B.1.351, B.1.617.2, and P.1) as Measured by MSD
Time frame: BD Day 29
Part 1C-1 GMC of Post-booster Pseudovirus nAb Against Variant Strain (B.1.1.529)
Time frame: BD Day 29
Part 3 SRR of Serum Pseudovirus nAb Post Dose 1 of mRNA-1273.222 Against Omicron BA.4/BA.5 Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: Day 29 Study P203/Day 57 Study P301
Part 3 Pseudovirus nAb SRR of Post Dose 1 of mRNA-1273.222 Against Ancestral Strain Compared With Those From Young Adult (18 to 25 Years of Age) Vaccine Recipients (Day 57) in Study P301
Time frame: Day 29 P203/Day 57 P301
Part 3 GM Value of Post Dose 1 (Day 29) of mRNA-1273.222 bAb Against Other Variants of Interest
Time frame: Day 29
Part 1C-2 GM Value of mRNA-1273 Booster Against Variants of Interest at Day 29
Time frame: Day 29
Part 1A GM Level of SARS-CoV-2 Spike Protein-specific bAb at Days 1, 57, 209, 394
Time frame: Days 1, 57, 209, 394
Part 1A GM Value of SARS-CoV-2-Specific nAb at Days 1, 57, 209, 394
Time frame: Days 1, 57, 209, 394
Part 1C-1 GM Value of Post-booster Dose Serum bAb Against Variants of Interest (B.1.1.7, B.1.351, B.1.617.2, and P.1) as Measured by MSD
Time frame: BD Day 29
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 15 Sep 2025.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 39332418Figueroa AL, Torres D, Reyes-Acuna C, Matherne P, Yeakey A, Deng W, Xu W, Sigal Y, Chambers G, Olsen M, Girard B, Miller JM, Das R, Priddy F. Safety and immunogenicity of a single-dose omicron-containing COVID-19 vaccination in adolescents: an open-label, single-arm, phase 2/3 trial. Lancet Infect Dis. 2025 Feb;25(2):208-217. doi: 10.1016/S1473-3099(24)00501-2. Epub 2024 Sep 24.
- Derived from this study: PubMed 34379915Ali K, Berman G, Zhou H, Deng W, Faughnan V, Coronado-Voges M, Ding B, Dooley J, Girard B, Hillebrand W, Pajon R, Miller JM, Leav B, McPhee R. Evaluation of mRNA-1273 SARS-CoV-2 Vaccine in Adolescents. N Engl J Med. 2021 Dec 9;385(24):2241-2251. doi: 10.1056/NEJMoa2109522. Epub 2021 Aug 11.
- Click here to access the website, http://TeenCoveStudy.com, for additional information for the study, such as Study Overview, Participation, Site Locations, along with contact numbers for each location for the study.Link provided by the sponsor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
53 sites in 2 countries: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing mRNA-1273 and mRNA-1273.222 in people with SARS-CoV-2, run by ModernaTX, Inc. at 53 sites in 2 countries.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 14 inclusion and 41 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 15 Sep 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 53 sites in United States, Dominican Republic. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
Yes. Results are posted in the registry (first posted 15 Sep 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Solicited Local and Systemic Adverse Reactions (ARs) (time frame: 7 days post-vaccination). The study lists 12 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04649151, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Sep 2025; AzTrials last refreshed its copy on 27 Oct 2026.