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Durability of Protection After Single Immunisation With GA2 Sporozoites (CoGA-Rechallenge)

ConditionMalaria,Falciparum
Trial statusNot yet recruiting
Trial phasePhase 1
Trial typeInterventional
Biological sexAll
Age18-35
SponsorLeiden University Medical Center

About this trial

This study will assess the durability of protection of a single immunisation with the Genetically Attenuated Parasite 2 (GA2) against controlled human malaria infection by rechallenging previously immunised and protected participants from the CoGA study (NCT05468606)

Eligibility criteria

This trial accepts healthy volunteers

Qualifiers

Participant is aged ≥18 and ≤35 years and in good health.

Rechallenge group only: participation in CoGA study, having received immunisation with 1x 50 GA2-infected MB, and protected during subsequent CHMI.

Participant has adequate understanding of the procedures of the study and agrees to abide strictly thereby.

Participant is able to communicate well with the investigator.

Disqualifiers

For participants of child bearing potential: breastfeeding, or positive serum pregnancy test prior to CHMI.

Infection controls only: any history of malaria or previous participation in any malaria (vaccine) study or CHMI.

Known hypersensitivity to or contra-indications for both atovaquone/proguanil or artemether/lumefantrine. QT prolonging drugs are only considered an exclusion criterion when QT prolongation is observed at the ECG at screening.

A history of severe (allergic) reactions to mosquito bites.

Trial design

Design model

Parallel

Treatments tested in this trial

  • CHMI with 3D7 malaria

    Biological/Vaccine

    Controlled human malaria infection with 3D7 malaria through mosquito bites

Treatment groups

14 Participants
are divided into 2 treatment groups
Group A: Rechallenge groupExperimental treatment 1 intervention
Group B: Infection control groupPlacebo comparator 1 intervention

Trial outcomes

Primary outcomes

1

Protective efficacy

Proportion of participants that do not develop parasitaemia (qPCR \>100p/mL) (sterile protection) after CHMI (re)challenge in participants with prior, single GA2 immunisation compared to infection controls.

Time frame
Moment of CHMI to antimalarial treatment (28 days post CHMI)
2

Time to parasitaemia

The time to parasitaemia (qPCR \>100 p/mL) (prepatent period) after CHMI (re)challenge between participants with prior, single GA2 immunisation and infection controls.

Time frame
Moment of CHMI to antimalarial treatment (28 days post CHMI)

Secondary outcomes

1

Humoral immune responses after homologous CHMI rechallenge

Difference in concentration of anti-CSP antibodies between groups as assessed by ELISA.

Time frame
Moment of CHMI up to182 days post CHMI
2

Cellular immune responses after homologous CHMI rechallenge

Difference in percentage of CD4+ and CD8+ T-cells producing IFN-γ between groups as assessed by flow cytometry

Time frame
Moment of CHMI up to182 days post CHMI

Other outcomes

Locations

This trial has no locations.

Sponsors and contacts

Click on the lead sponsor to view all of their trials.

Leiden University Medical Center

Lead sponsor

Source ClinicalTrials.gov

This trial is not recruiting at the moment. You can still explore other options: