Clinical Trials Register

Summary
EudraCT Number:	2026-000021-16
Sponsor's Protocol Code Number:	VLA1553-321
Clinical Trial Type:	Outside EU/EEA
Date on which this record was first entered in the EudraCT database:	2026-03-03
Trial results

Index
A. PROTOCOL INFORMATION
B. SPONSOR INFORMATION
C. APPLICANT IDENTIFICATION
D. IMP IDENTIFICATION
D.8 INFORMATION ON PLACEBO
E. GENERAL INFORMATION ON THE TRIAL
F. POPULATION OF TRIAL SUBJECTS
G. INVESTIGATOR NETWORKS TO BE INVOLVED IN THE TRIAL
H.4 THIRD COUNTRY IN WHICH THE TRIAL WAS FIRST AUTHORISED

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A. Protocol Information

A.2

EudraCT number

2026-000021-16

A.3

Full title of the trial

A Multicenter, Randomized, Controlled, Double Blinded Pivotal Study to Evaluate Safety and Immunogenicity of a Live-attenuated Chikungunya Virus Vaccine Candidate (VLA1553) in Adolescents Aged 12 Years to <18 Years

PIP #: P/0457/2021 and P/0501/2023

A.3.1

Title of the trial for lay people, in easily understood, i.e. non-technical, language

A Multicenter Study to Evaluate Safety and Immunogenicity of a Live-attenuated Chikungunya Vaccine in Adolescents

A.3.2

Name or abbreviated title of the trial where available

A Multicenter Study to Evaluate Safety and Immunogenicity of a Live-attenuated Chikungunya Vaccine

A.4.1

Sponsor's protocol code number

VLA1553-321

A.5.2

US NCT (ClinicalTrials.gov registry) number

NCT04650399

A.7

Trial is part of a Paediatric Investigation Plan

Yes

A.8

EMA Decision number of Paediatric Investigation Plan

P/501/2023

B. Sponsor Information
B.Sponsor: 1
B.1.1	Name of Sponsor	Instituto Butantan (Principal Sponsor in Brazil)
B.1.3.4	Country	Brazil
B.3.1 and B.3.2	Status of the sponsor	Non-Commercial
B.4 Source(s) of Monetary or Material Support for the clinical trial:
B.4.1	Name of organisation providing support	Valneva Austria GmbH
B.4.2	Country	Austria
B.4.1	Name of organisation providing support	Instituto Butantan
B.4.2	Country	Brazil
B.4.1	Name of organisation providing support	Coalition for Epidemic Preparedness Innovations
B.4.2	Country	Norway
B.4.1	Name of organisation providing support	EU Horizon 2020
B.4.2	Country	Belgium
B.5 Contact point designated by the sponsor for further information on the trial
B.5.1	Name of organisation	Valneva Austria GmbH
B.5.2	Functional name of contact point	Study Director
B.5.3	Address:
B.5.3.1	Street Address	Campus Vienna Biocenter 3
B.5.3.2	Town/ city	Vienna
B.5.3.3	Post code	1030
B.5.3.4	Country	Austria
B.5.4	Telephone number	00431206200
B.5.5	Fax number	0043120620
B.5.6	E-mail	office@valneva.com
B.Sponsor: 2
B.1.1	Name of Sponsor	Valneva Austria GmbH (Development lead and Co-Sponsor)
B.1.3.4	Country	Austria
B.3.1 and B.3.2	Status of the sponsor	Commercial
B.4 Source(s) of Monetary or Material Support for the clinical trial:
B.4.1	Name of organisation providing support	Valneva Austria GmbH
B.4.2	Country	Austria
B.4.1	Name of organisation providing support	Instituto Butantan
B.4.2	Country	Brazil
B.4.1	Name of organisation providing support	Coalition for Epidemic Preparedness Innovations
B.4.2	Country	Norway
B.4.1	Name of organisation providing support	EU Horizon 2020
B.4.2	Country	Belgium
B.5 Contact point designated by the sponsor for further information on the trial
B.5.1	Name of organisation	Valneva Austria GmbH
B.5.2	Functional name of contact point	Study Director
B.5.3	Address:
B.5.3.1	Street Address	Campus Vienna Biocenter 3
B.5.3.2	Town/ city	Vienna
B.5.3.3	Post code	1030
B.5.3.4	Country	Austria
B.5.4	Telephone number	00431206200
B.5.5	Fax number	0043120620
B.5.6	E-mail	office@valneva.com

D. IMP Identification
D.IMP: 1
D.1.2 and D.1.3	IMP Role	Test
D.2	Status of the IMP to be used in the clinical trial
D.2.1	IMP to be used in the trial has a marketing authorisation	No
D.2.5	The IMP has been designated in this indication as an orphan drug in the Community	No
D.2.5.1	Orphan drug designation number
D.3 Description of the IMP
D.3.1	Product name	CHIKV vaccine
D.3.2	Product code	VLA1553
D.3.4	Pharmaceutical form	Lyophilisate for solution for injection
D.3.4.1	Specific paediatric formulation	No
D.3.7	Routes of administration for this IMP	Intramuscular use
D.3.11 The IMP contains an:
D.3.11.1	Active substance of chemical origin	No
D.3.11.2	Active substance of biological/ biotechnological origin (other than Advanced Therapy IMP (ATIMP)	Yes
	The IMP is a:
D.3.11.3	Advanced Therapy IMP (ATIMP)	No
D.3.11.3.1	Somatic cell therapy medicinal product	No
D.3.11.3.2	Gene therapy medical product	No
D.3.11.3.3	Tissue Engineered Product	No
D.3.11.3.4	Combination ATIMP (i.e. one involving a medical device)	No
D.3.11.3.5	Committee on Advanced therapies (CAT) has issued a classification for this product	No
D.3.11.4	Combination product that includes a device, but does not involve an Advanced Therapy	No
D.3.11.5	Radiopharmaceutical medicinal product	No
D.3.11.6	Immunological medicinal product (such as vaccine, allergen, immune serum)	Yes
D.3.11.7	Plasma derived medicinal product	No
D.3.11.8	Extractive medicinal product	No
D.3.11.9	Recombinant medicinal product	No
D.3.11.10	Medicinal product containing genetically modified organisms	Yes
D.3.11.11	Herbal medicinal product	No
D.3.11.12	Homeopathic medicinal product	No
D.3.11.13	Another type of medicinal product	No

D.8 Information on Placebo
D.8 Placebo: 1
D.8.1	Is a Placebo used in this Trial?	Yes
D.8.3	Pharmaceutical form of the placebo	Solution for injection
D.8.4	Route of administration of the placebo	Intramuscular use

E. General Information on the Trial

E.1 Medical condition or disease under investigation

E.1.1

Medical condition(s) being investigated

healthy volunteers

active immunization for the prevention of Chikungunya virus infection

E.1.1.1

Medical condition in easily understood language

A vaccine that helps protect people from getting sick from the chikungunya virus. Chikungunya is a virus infection that people can get from mosquito bites.

E.1.1.2

Therapeutic area

Diseases [C] - Virus Diseases [C02]

MedDRA Classification

E.1.2 Medical condition or disease under investigation

E.1.2	Version	20.1
E.1.2	Level	PT
E.1.2	Classification code	10067256
E.1.2	Term	Chikungunya virus infection
E.1.2	System Organ Class	10021881 - Infections and infestations

E.1.3

Condition being studied is a rare disease

E.2 Objective of the trial

E.2.1

Main objective of the trial

To evaluate immunogenicity and safety of the full dose of the live-attenuated CHIKV vaccine candidate (VLA1553) 28 days following vaccination in adolescents aged 12 years to <18 years after a single immunization.

E.2.2

Secondary objectives of the trial

To assess the immunogenicity and safety of the full dose of VLA1553 following vaccination in adolescents aged 12 years to <18 years after a single immunization up to Month 12.
To assess the immunogenicity and safety of VLA1553 in subjects previously exposed to chikungunya virus.

E.2.3

Trial contains a sub-study

E.3

Principal inclusion criteria

- Male or female adolescents from the 12th birthday to the last day before the 18th birthday at the time of vaccination;
- written informed consent by the subject’s legal representatives, and written informed assent of the subject;
- generally healthy as determined by the Investigator's clinical judgement based on medical history, physical examination and screening laboratory tests;
- seropositive for previous CHIKV exposure (i.e. IgM+/IgG+ or IgM-/IgG+) or seronegative (i.e. IgM-/IgG-) as screened by CHIKV-specific ELISA.
- for women of childbearing potential:
- negative serum or urine pregnancy test at screening and on Day 1.
- practiced an adequate method of contraception during 30 days before screening
- agreed to employ adequate birth control measures for the first three months post-vaccination (i.e. until Day 85).

E.4

Principal exclusion criteria

- was taking medication or other treatment for unresolved symptoms attributed to a previous CHIKV infection; or had participated in a clinical study involving an investigational CHIKV vaccine;
- acute or recent infection;
- tested positive for human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg) or hepatitis C virus (HCV);
- abnormal findings in any required study investigations (including medical history, physical examination, and clinical laboratory) considered clinically relevant by the Investigator which pose a risk for participation in the study;
- medical history of or currently had acute or progressive, unstable or uncontrolled clinical conditions that posed a risk for participation in the study;
- history of immune-mediated or clinically relevant arthritis / arthralgia;
- history of malignancy in the past 5 years other than squamous cell or basal cell skin cancer. If there had been surgical excision or treatment more than 5 years ago that was considered to have achieved a cure, the subject could be enrolled;

E.5 End points

E.5.1

Primary end point(s)

Proportion of subjects with a seroprotective CHIKV antibody level defined as μPRNT50 ≥ 150 for μPRNT baseline negative subjects 28 days post-vaccination.

E.5.1.1

Timepoint(s) of evaluation of this end point

28 days after vaccination

E.5.2

Secondary end point(s)

Immunogenicity:
I1. Immune response as measured by CHIKV-specific neutralizing antibody titers on Day 8, Day 29, Day 85, Day 180, and Month 12 post-vaccination as determined by μPRNT assay;
I2. Proportion of subjects with seroprotective levels (defined as μPRNT50 ≥ 150 for μPRNT baseline negative subjects) on Day 8, Day 85, Day 180 and Month 12 post-vaccination as determined by μPRNT assay;
I3. Proportion of subjects with seroconversion (defined as >4-fold increase of µPRNT50 compared to baseline) at Day 29, Day 180 and Month 12 post-vaccination as determined by μPRNT assay;
I4. Fold increase of CHIKV-specific neutralizing antibody titers determined by μPRNT assay at Days 8, 29, 85, 180 and at Month 12 post-vaccination as compared to baseline;
I5. Proportion of subjects reaching an at least 4-fold, 8-fold, 16-fold or 64-fold increase in CHIKV-specific neutralizing antibody titer compared to baseline as measured by μPRNT assay;
I6. Antibody titers, seroprotection and fold increases for CHIKV-specific neutralizing antibodies, determined by μPRNT assay at Days 1, 8, 29, 85, 180, and Month 12 post-vaccination stratified by μPRNT baseline serostatus.

Safety:
S1. Frequency and severity of unsolicited AEs until Day 29 and Month 6 post-vaccination;
S2. Frequency and severity of solicited injection site and systemic reactions within ten days post-vaccination;
S3. Frequency and relatedness of any serious adverse event (SAE) during the entire study period;
S4. Frequency and severity of any early onset adverse event of special interest (AESI) starting within 2 to 21 days post-vaccination (i.e. Day 3 – Day 22);
S5. Frequency and severity of any late onset adverse event of special interest (AESI) during the entire study starting 22 days post-vaccination (i.e. Day 23 – study end);
S6. Assessment of viremia on Days 1 and 8 (and Day 29, if applicable) after vaccination.

E.5.2.1

Timepoint(s) of evaluation of this end point

Immunogenicity:
I1. on Day 8, Day 29, Day 85, Day 180, and Month 12 post-vaccination;
I2. on Day 8, Day 85, Day 180 and Month 12 post-vaccination;
I3. at Day 29, Day 180 and Month 12;
I4. at Days 8, 29, 85, 180 and at Month 12 post-vaccination;
I5. at Days 8, 29, 85, 180 and at Month 12 post-vaccination;
I6. at Days 1, 8, 29, 85, 180, and Month 12 post-vaccination.

Safety:
S1. until Day 29 and Month 6 post-vaccination;
S2. within 10 days post-vaccination;
S3. during the entire study period;
S4. starting within 2 to 21 days post-vaccination (i.e. Day 3 – Day 22);
S5. during the entire study starting 22 days post-vaccination (i.e. Day 23 – study end);
S6. on Days 1 and 8 (and Day 29, if applicable) after vaccination;

E.6 and E.7 Scope of the trial

E.6

Scope of the trial

E.6.1

Diagnosis

E.6.2

Prophylaxis

E.6.3

Therapy

E.6.4

Safety

Yes

E.6.5

Efficacy

E.6.6

Pharmacokinetic

E.6.7

Pharmacodynamic

E.6.8

Bioequivalence

E.6.9

Dose response

E.6.10

Pharmacogenetic

E.6.11

Pharmacogenomic

E.6.12

Pharmacoeconomic

E.6.13

Others

Yes

E.6.13.1

Other scope of the trial description

Immunogenicity

E.7

Trial type and phase

E.7.1

Human pharmacology (Phase I)

E.7.1.1

First administration to humans

E.7.1.2

Bioequivalence study

E.7.1.3

Other

E.7.1.3.1

Other trial type description

E.7.2

Therapeutic exploratory (Phase II)

E.7.3

Therapeutic confirmatory (Phase III)

Yes

E.7.4

Therapeutic use (Phase IV)

E.8 Design of the trial

E.8.1

Controlled

Yes

E.8.1.1

Randomised

Yes

E.8.1.2

Open

E.8.1.3

Single blind

E.8.1.4

Double blind

Yes

E.8.1.5

Parallel group

E.8.1.6

Cross over

E.8.1.7

Other

E.8.2

Comparator of controlled trial

E.8.2.1

Other medicinal product(s)

E.8.2.2

Placebo

Yes

E.8.2.3

Other

E.8.2.4

Number of treatment arms in the trial

E.8.3

Will this trial be conducted at a single site globally?

E.8.4

Will this trial be conducted at multiple sites globally?

Yes

E.8.6 Trial involving sites outside the EEA

E.8.6.2

Trial being conducted completely outside of the EEA

Yes

E.8.6.3

Specify the countries outside of the EEA in which trial sites are planned

Brazil

E.8.7

Trial has a data monitoring committee

Yes

E.8.8

Definition of the end of the trial and justification where it is not the last visit of the last subject undergoing the trial

LVLS

E.8.9 Initial estimate of the duration of the trial

E.8.9.2

In all countries concerned by the trial years

E.8.9.2

In all countries concerned by the trial months

E.8.9.2

In all countries concerned by the trial days

F. Population of Trial Subjects

F.1 Age Range

F.1.1

Trial has subjects under 18

Yes

F.1.1

Number of subjects for this age range:

750

F.1.1.1

In Utero

F.1.1.2

Preterm newborn infants (up to gestational age < 37 weeks)

F.1.1.3

Newborns (0-27 days)

F.1.1.4

Infants and toddlers (28 days-23 months)

F.1.1.5

Children (2-11years)

F.1.1.6

Adolescents (12-17 years)

Yes

F.1.1.6.1

Number of subjects for this age range:

750

F.1.2

Adults (18-64 years)

F.1.3

Elderly (>=65 years)

F.2 Gender

F.2.1

Female

Yes

F.2.2

Male

Yes

F.3 Group of trial subjects

F.3.1

Healthy volunteers

Yes

F.3.2

Patients

F.3.3

Specific vulnerable populations

Yes

F.3.3.1

Women of childbearing potential not using contraception

F.3.3.2

Women of child-bearing potential using contraception

Yes

F.3.3.3

Pregnant women

F.3.3.4

Nursing women

F.3.3.5

Emergency situation

F.3.3.6

Subjects incapable of giving consent personally

F.3.3.7

Others

F.4 Planned number of subjects to be included

F.4.2

For a multinational trial

F.4.2.2

In the whole clinical trial

750

F.5

Plans for treatment or care after the subject has ended the participation in the trial (if it is different from the expected normal treatment of that condition)

None

G. Investigator Networks to be involved in the Trial
G.4 Investigator Network to be involved in the Trial: 1
G.4.1	Name of Organisation	Centro de Pesquisa e Desenvolvimento de Fàrmacos - Universidade Federal de Minas Gerais
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 2
G.4.1	Name of Organisation	Centro de Estudos do Instituto de Infectologia Emílio Ribas
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 3
G.4.1	Name of Organisation	CECOR - Centro Oncológico de Roraima
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 4
G.4.1	Name of Organisation	Fundação de Medicina Tropical Dr. Heitor Vieira Dourado
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 5
G.4.1	Name of Organisation	Universidade Federal do Ceará - Núcleo de Pesquisa e Desenvolvbimento de Medicamentos
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 6
G.4.1	Name of Organisation	Obras Sociais Irmã Dulce
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 7
G.4.1	Name of Organisation	Real Hospital Português de Beneficência
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 8
G.4.1	Name of Organisation	Fundação Faculdade Regional de Medicina de São José do Rio Preto
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 9
G.4.1	Name of Organisation	Universidade Federal de Sergipe (UFS) - Campus Laranjeiras
G.4.3.4	Network Country	Brazil
G.4 Investigator Network to be involved in the Trial: 10
G.4.1	Name of Organisation	Centro de Pesquisa Clinica da Faculdade de Medicina da Universidade Federal de Mato Grosso do Sul
G.4.3.4	Network Country	Brazil

H.4 Third Country in which the Trial was first authorised
H.4.1	Third Country in which the trial was first authorised:	Brazil

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