A Controlled Human Vivax Malaria Infection Study Through Inoculation of Infected Erythrocytes

Summary

The primary objectives of this study are to assess the safety and feasibility of blood-stage controlled human P. vivax malaria infection (CHMI) in healthy adult Thai volunteers through experimental injection of cryopreserved P. vivax infected erythrocytes, and to choose the optimal inoculation dose for future P. vivax CHMI studies. In this study, blood-stage CHMI will be conducted in 8 volunteers per inoculum stock who will each be infected with P. vivax by experimental injection with cryopreserved P. vivax infected erythrocytes, which were collected from the controlled human Plasmodium vivax malaria infection model through experimental sporozoite infection in Thai adults (NCT04083508) . There are currently 4 stocks of inocula from 6 volunteers in the NCT04083508 study, which have differing quantities and stages of parasites.

The total number of volunteers of this study will be up to 48 (8 volunteers per inocula stock). The volunteers will be monitored closely as in-patients in the Hospital for Tropical Diseases, and will be treated according to the Research Proposal.

This study is funded by the UK Wellcome Trust. The grant reference number are Oxford/MORU: 212336/Z/18/Z and 212336/Z/18/A, and Mahidol University: 212336/A/18/Z and 212336/A/18/A.

Conditions

• Plasmodium Vivax Infection

Interventions

BIOLOGICAL

An inoculum of malaria parasitised red blood cells with whole dose blood-stage inoculum

An inoculum of malaria parasitised red blood cells reconstituted in 0.9% normal saline, to a total volume of 5 mL; challenge with whole dose blood-stage inoculum (neat)

BIOLOGICAL

An inoculum of malaria parasitised red blood cells with 1:5 dilution blood-stage inoculum

An inoculum of malaria parasitised red blood cells reconstituted in 0.9% normal saline, to a total volume of 5 mL; challenge with 1:5 dilution blood-stage inoculum

BIOLOGICAL

An inoculum of malaria parasitised red blood cells with 1:10 dilution blood-stage inoculum

An inoculum of malaria parasitised red blood cells reconstituted in 0.9% normal saline, to a total volume of 5 mL; challenge with 1:10 dilution blood-stage inoculum

BIOLOGICAL

An inoculum of malaria parasitised red blood cells with 1:20 dilution blood-stage inoculum

An inoculum of malaria parasitised red blood cells reconstituted in 0.9% normal saline, to a total volume of 5 mL; challenge with 1:20 dilution blood-stage inoculum

Sponsors & Collaborators

• University of Oxford

  lead OTHER

• Wellcome Trust

  collaborator OTHER

Principal Investigators

• Nicholas Day, MD · University of Oxford

Study Design

Allocation

RANDOMIZED

Purpose

OTHER

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

20 Years

Max Age

55 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-05-23

Primary Completion

2026-11-30

Completion

2026-11-30

Countries

• Thailand

Study Locations