NCT06655324 · Merck Sharp & Dohme LLC
A Study to Evaluate Safety, Tolerability, and Immunogenicity of V350A and V350B in Healthy Participants (V350-001).
What this study is about
Epstein Barr virus (EBV) is a virus which can cause infectious mononucleosis and is associated with certain kinds of cancer and multiple sclerosis. Researchers are looking for new ways to prevent disease related to EBV and have developed a new study vaccine (V350A and V350B).
View original scientific description
Epstein Barr virus (EBV) is a virus which can cause infectious mononucleosis and is associated with certain kinds of cancer and multiple sclerosis. Researchers are looking for new ways to prevent disease related to EBV and have developed a new study vaccine (V350A and V350B). The main goal of this study is to learn about the safety and tolerability of V350A and V350B in healthy adults.
Interventions
BIOLOGICAL
V350A
Vaccination administered via intramuscular injection
BIOLOGICAL
V350B
Vaccination administered via intramuscular injection
BIOLOGICAL
Placebo
Vaccination administered via intramuscular injection
Primary outcome measures
Number of Participants with Solicited Injection Site Adverse Events (AEs)
Time frame: Up to approximately 6 months
An adverse event (AE) is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Solicited injection site AEs will be recorded on a vaccination report card (VRC).
Number of Participants with Solicited Systemic AEs
Time frame: Up to approximately 6 months
An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Solicited systemic AEs will be recorded on a VRC.
Number of Participants with Immediate AEs Following Vaccinations
Time frame: Up to approximately 6 months
An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Participants will be observed following vaccination for immediate AEs.
Number of Participants with Unsolicited AEs
Time frame: Up to approximately 7 months
An AE is any untoward medical occurrence in a patient or clinical study participant, temporally associated with the use of study intervention, whether or not considered related to the study intervention. Unsolicited AEs will be recorded on a VRC.
Number of Participants with Serious AEs
Time frame: Up to approximately 18 months
A serious adverse event (SAE) is an AE that results in death, is life threatening, results in a persistent or significant disability or incapacity, results in or prolongs an existing hospitalization, is a congenital anomaly or birth defect, is a cancer, is an overdose, or is another important medical event.
Number of Participants with Medically Attended Adverse Events (MAAEs)
Time frame: Up to approximately 18 months
A MAAE is an AE in which medical attention is received during an unscheduled, non-routine outpatient visit, such as an emergency department visit, office visit, or an urgent care visit with any medical personnel for any reason. Routine visits are not considered MAAEs.
Number of Participants with Events of Clinical Interest (ECIs)
Time frame: Up to approximately 18 months
ECIs are selected serious and nonserious AEs are defined as an overdose of Sponsor's product, drug-induced liver injury events, or potential immune-mediated diseases (pIMDs).
Who can participate
This study lists these criteria on ClinicalTrials.gov. A study coordinator reviews eligibility during screening — this page does not determine whether you qualify.
Inclusion criteria
- The key inclusion criteria include but are not limited to the following:
- Is in good health before randomization.
- Has a body mass index between 18 and 38 kg/m\^2, inclusive, for adults 18-30; has a body mass index between 15 and 38 kg/m\^2, inclusive, for adolescents 12-17.
Exclusion criteria
- The key exclusion criteria include but are not limited to the following:
- Has a confirmed or suspected case of infectious mononucleosis within 12 months prior to enrollment.
- Has any immunosuppressive medical condition or receive any immunosuppressive therapy.
Where
- Glendale, California
- Miami, Florida
- Kansas City, Missouri
- Springfield, Missouri
- Lincoln, Nebraska
- Omaha, Nebraska
- Columbus, Ohio
- Oklahoma City, Oklahoma
- Knoxville, Tennessee
Related conditions & keywords
Frequently asked questions
What is a clinical trial?
A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.
Is it safe to participate?
Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.
Will I be compensated?
Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.
Will I receive a placebo instead of treatment?
When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.
Can I leave a trial if I change my mind?
Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.
How long does a clinical trial last?
Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.
Data: ClinicalTrials.gov · synced Aug 25, 2026 · Source of record for eligibility and locations