A Trial to Evaluate the Safety and Immunogenicity of VLA1553 in Healthy Children (NCT07133178) | Clinical Trial Compass
WithdrawnPhase 3
A Trial to Evaluate the Safety and Immunogenicity of VLA1553 in Healthy Children
Stopped: No participant recruited; trial initiation postponed to an unspecified future time while Valneva assesses potential pathways to address regulatory requests. Evaluation is ongoing to ensure alignment with regulatory expectations and obligations.
0Started 2026-02-06
Plain-language summary
VLA1553-322 is a multicenter, prospective, randomized, double-blind, phase 3 clinical trial evaluating VLA1553 in comparison to a comparator (Nimenrix®) for each stratum (age group). At least 3,000 male and female healthy children aged 1 to 11 years will be enrolled and randomized 3:1 to either VLA1553 (n=2,250) or comparator (Nimenrix®) (n=750).
Who can participate
Age range
1 Year – 11 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Male or female healthy children aged 7 to 11 years for Stratum A, 3 to 6 years for Stratum B and 1 to 2 years for Stratum C at the time of obtaining participant informed consent / assent;
. Written informed consent by the participant's parent(s) / Legally Acceptable Representative(s) (LAR(s), according to local requirements, and written informed assent of the participant, if applicable;
. Participant is generally healthy as determined by the Investigator's clinical judgement based on medical history, physical examination and screening laboratory tests;
. Participants in Stratum C (1 to 2 years) must be within the normal WHO growth and weight ranges for their age.
. Participant is seropositive for previous CHIKV exposure (i.e. IgM+ / IgG+ or IgM- / IgG+) or seronegative (i.e. IgM- / IgG-);
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
The proportion of participants with a seroresponse as defined by μPRNT50 for baseline negative participants
. If participant is of childbearing potential (e.g. after onset of menarche) and if involved in activities that could result in pregnancy:
. Female participant has a negative pregnancy test (in accordance with local regulations) at Screening (Visit 0) and Day 1 (Visit 1), respectively;
. Female participant has practiced an adequate method of contraception during at least the 30 days before Screening (Visit 0) and during the Screening period;
Exclusion criteria
. Participant who is anti-CHIKV IgM+ / IgG- does not qualify for participation in this trial.
. Participant is taking medication or other treatment for unresolved symptoms attributed to a previous CHIKV infection; or has participated in a clinical trial involving an investigational CHIKV vaccine;
. Participant has an acute or recent infection and who is not symptom-free in the week prior to both the Screening visit (Visit 0) and Visit 1;
. Participant has received another live virus vaccine within 28 days or inactivated / other vaccine within 14 days prior to vaccination in this trial or plans to receive a live virus vaccine within 28 days or inactivated vaccine / other within 14 days after vaccination; Whenever possible, standard of care vaccinations should be planned with the trial VLA1553 administration in mind.
. Participant has an ongoing medical history of or currently has acute or progressive, unstable, controlled or uncontrolled clinical condition (e.g., cardiovascular, respiratory, neurologic, psychiatric, or rheumatologic conditions) that poses a risk for participation in the trial, based on the Investigators clinical judgement. Examples include individuals with controlled, poorly controlled or unstable disease, ongoing suspected or active inflammation, or poor compliance with pharmacologic treatment, or presence of high-risk comorbidities (e.g., significant cardiopulmonary disease);
. Participant has abnormal findings in any required trial investigations (including medical history, physical examination, and clinical laboratory) considered clinically relevant by the Investigator which pose a risk for participation in the trial based on his / her judgement;
. Participant has a history of immune-mediated or clinically relevant arthritis / arthralgia;
. The participant, their parent(s) / LAR(s) or siblings have a known HIV, hepatitis B or hepatitis C infection;