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 range1 Year – 11 Years
SexALL
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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-);
✓. 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;
What they're measuring
1
The proportion of participants with a seroresponse as defined by μPRNT50 for baseline negative participants
✕. 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;