You are invited to take part in a study to investigate how the immune system responds to repeated malaria infection. The study is being run by the Oxford Vaccine Group in partnership with the Department of Biochemistry/Paediatrics which is part of the University of Oxford and is funded by the Medical Research Council (MRC).

We are currently recruiting for Group 3. Group 3 participants will act as a healthy control group and undergo a bone marrow sample only. This will allow comparison with samples from Group 1 and Group 2 participants who have also undergone a controlled malaria infection (“malaria challenge”). Group 3 participants will not undergo a malaria challenge or vaccination.

If you are aged from 18 to 45 years old, in good health and live in the Oxford area, then you may be eligible to take part in the study. The total study duration is 3 months (screening appointment, bone marrow test and 1 x follow up appointment). We will reimburse you up to £260 for your time, inconvenience, and travel.

Background

Malaria is an infectious disease caused by the Plasmodium parasite and is a major public health problem in many parts of the world. Malaria is spread by the bite of an infected mosquito. There are five species of the Plasmodium parasite that are known to cause malaria in humans. Of these five species, Plasmodium falciparum causes the most sickness and death globally, with an estimated 241 million cases of malaria and 619,000 deaths worldwide in 2021. Most of the deaths from malaria occur in children under five living in Africa, with infants under one year being at the highest risk.

An important study conducted in Tanzania showed that while the amount of malaria parasite in the blood remains constant over the first few malaria infections in life, the risk of severe disease and hospitalisation decreases significantly with each infection. This study concluded that rather than killing the malaria parasite, the immune system developed the ability to ‘tolerate’ the presence of the malaria parasite in the body after repeated infections. This limits the damage the infection causes. While this was an important finding, the way the immune system actually “tolerates” the malaria parasite remains unknown.

Study information

In order to better understand how the immune system adapts to tolerate the malaria parasite after repeated malaria infections, we have recruited people to undergo three malaria “challenges” approximately five months apart (Groups 1 and 2). Group 1 and 2 recruitment is now closed. In a malaria “challenge”, study participants are deliberately infected with malaria under very carefully regulated conditions. This means we will know the exact moment of infection and will be able to track the immune response that follows. We will observe participants closely and take blood daily to measure the parasite growth in their blood and analyse the immune response. Once participants develop malaria (confirmed by detecting parasites in the blood), we will start malaria treatment to clear the infection.

Participants in Groups 1 and 2 will also undergo a bone marrow test. The bone marrow test uses a needle to take a sample of bone marrow. As many immune cells are produced and live in the bone marrow, this procedure will allow us to “track” activated immune cells so we can investigate how they respond to the malaria infections.

We have now fully recruited Groups 1 and 2 and are recruiting a third group of participants (Group 3). Participants in Group 3 will be asked to undergo bone marrow sampling only. They will not undergo malaria challenge and will not receive a vaccine. These participants will be healthy ‘control’ participants to compare the bone marrow samples from Groups 1 and 2 with ‘normal’ bone marrow samples (Group 3). This group will have a screening visit, bone marrow procedure and one telephone call follow up appointment only.

If you would like to find out more, please read the Participant Information Sheet (Group 3 only) :

If you are interested in joining the study, please visit the Prescreening Questionnaire where you can access the online screening questions and register your interest. This questionnaire takes around 5-10 min to complete :

There is no obligation to participate in any study. For more information about how your details are stored, please refer to the Participant Information Sheet (Group 3 only) above.

If you would like any further information regarding the study, please contact us on:

Email: info@ovg.ox.ac.uk

Telephone: 01865 611400