Safety and Immunogenicity Study of Plasmodium Vivax CS Derived Synthetic Peptides Formulated in Two Adjuvants

• Status: Completed
• Trial end date: 2006-04-01
• Target enrollment: 0
• Participant gender: All

Summary

This was a phase I double blind controlled vaccine trial, evaluating safety, tolerability and immunogenicity of mixtures of N, R and C LSP derived from the P. vivax CS protein formulated in two adjuvants Montanide ISA 720 and Montanide ISA 51.

The primary objective was to assess in malaria-naïve adults, the safety and reactogenicity of these peptides formulated in the two adjuvants

We recruited 40 healthy men and women volunteers from Cali, Colombia, a city non-endemic for malaria. Volunteers were 19--41 years of age and had no history of malaria. During a period of three months a total of 100 volunteers were assessed for eligibility criteria in order to select a total of 40 volunteers willing to participate in the clinical trial. By consecutive allocation, eight participants were allocated to each of the five experimental groups (A--E): four groups (A--D) were immunized with the vaccine formulations at two different dose concentrations and formulated in two different adjuvants. A control group (E) was injected with placebo (saline solution)

• Phase: Phase 1
• Accepts Healthy Volunteers?: Accepts Healthy Volunteers

Details

• Lead Sponsor: Malaria Vaccine and Drug Development Center
• Collaborators: Asoclinic Inmunología Ltda.; Centro médico Imbanaco
• Treatments: Freund's Adjuvant; Mannitol

Criteria

Inclusion Criteria:

• Healthy adults (male and non-pregnant female) 18- 45 years old, without previously malaria infection (naïve volunteers), capable to pass a comprehension test on the study and able to provide written informed consent to participate in the trial.

• Use of adequate contraceptive method since the initiation of the study and until two months after the end of the study.

• No plans to travel to a malaria endemic area during the course of the study.

• Reachable by phone during the study period (1 year).

• No use of other vaccines since 3 months before the beginning of the study and during it.

Exclusion Criteria:

• Females who intend to become pregnant within the 3 months following the screening visit or who are pregnant at screening time, ascertained by urine or serum pregnancy test (B-HCG). Women who are breast-feeding will also be excluded. Reason for exclusion: The immunological changes accompanying pregnancy and lactation could alter the results of the assays performed. If a pathological condition appear, it could be carried to the vaccine.

• Duffy negative phenotype. Justification: Individuals with this phenotype are refractory to P. vivax infection.

• G-6-PD deficiency or any genetic defect (hemoglobinopathy). Justification: These conditions influence the development of P. vivax infection.

• History of previous experimental malaria vaccination. Justification: Individuals who have been previously immunized may show a response due to the past immunization and not to the present one.

• Clinical or laboratory evidence of significant systemic disease, including hepatic, renal, cardiac, immunologic or hematological disease.

Justification: The results of the study could have a negative impact on the study if volunteers are suffering from any of these diseases.

• Evidence of active hepatitis B or C or HIV infection. Justification: Serious underlying medical condition could affect the immunological responses of volunteers or could increase the risk or severity of adverse events associated with participation in this study.

• Clinically significant laboratory abnormalities as determined by the investigator(s).

Justification: Baseline abnormal laboratory values may indicate a serious underlying medical condition and also will make it difficult to evaluate AE´s during the conduct of the study.

• Known history of autoimmune (including inflammatory bowel disease, rheumatoid arthritis, lupus) or connective tissue disease.

Justification: Autoimmune diseases could affect the immunological responses of volunteers and could increase the risk to the volunteer.

• Individuals receiving treatment with steroids or non-steroidal anti-inflammatory drugs or any immunosuppressive therapy.

Justification: These drugs could affect the immunological responses of volunteers and could increase the risk to the volunteer.

• Known history of drug or alcohol abuse interfering with normal social function. Justification: Pharmaco-dependency alters the capacity of free decision and produce physical or psychiatric undesirable condition that could affect the study.

• Volunteers unable to give written informed consent or with difficulties to understand the study.

Justification: Volunteers must have the capacity to provide informed consent in order to participate in any research involving humans