An open label phase I/IIa clinical trial to assess the safety, immunogenicity and efficacy of the blood-stage malaria vaccine candidates R78C and RH5.1 in Matrix-M
Healthy volunteers, testing investigational Malaria vaccines
Current interventions as of 01/04/2026: We will testing the safety and efficacy of the vaccines, R78C and RH5.1, which are given in combination with the adjuvant Matrix-M. Group 1 participants will receive the combination of 10 ug of RH5.1 with 10 ug of R78C (with 50 ug Matrix M), given in a 0,1,5-month regimen. Group 2 will be a control group and will not receive any vaccinations. Safety will be assessed in vaccinated participants by follow up and collected of solicited and unsolicited adverse events after each vaccination. Efficacy will be tested by time to malaria diagnosis at blood stage controlled human malaria infection. _____ Previous interventions as of 10/09/2025: We will testing the safety and efficacy of the vaccines, R78C and RH5.1, which are given in combination with the adjuvant Matrix-M. Group 1 participants will receive the combination of 10 ug of RH5.1 with 10 ug of R78C (with 50 ug Matrix M), given in a 0,1,6-month regimen. Group 2 will be a control group and will not receive any vaccinations. Safety will be assessed in vaccinated participants by follow up and collected of solicited and unsolicited adverse events after each vaccination. Efficacy will be tested by time to malaria diagnosis at blood stage controlled human malaria infection. _____ Previous interventions: We will testing the safety and efficacy of the vaccines, R78C and RH5.1, which are given in combination with the adjuvant Matrix-M. Group 1 participants will receive the combination of 10 ug of RH5.1 with 10 ug of R78C (with 50 ug Matrix M), given in a 0,1,2-month regimen. Group 2 participants will be returning participants from a previous vaccine trial (VAC089). They will receive one 'booster' dose of vaccine: either 10 ug of R78C or the combination of 10ug R78C with 10 ug RH5.1 (both with 50ug of Matrix M), depending on Group allocation. Group 3 will be a control group and will not receive any vaccinations. Safety will be assessed in vaccinated participants by follow up and
Current inclusion criteria as of 10/09/2025: 1. Healthy adult aged 18 to 45 years. 2. Able and willing (in the Investigator’s opinion) to comply with all study requirements. 3. Willing to allow the Investigators to access participant’s electronic medical records and discuss the participant’s medical history with their GP. 4. Able and willing to provide written informed consent to participate in the trial. 5. Participants of childbearing potential only: must practice continuous effective contraception for the duration of the study. 6. Negative haemoglobinopathy screen (including screening for sickle cell disease and alpha and beta thalassaemia) and normal G6PD levels. 7. Agreement to permanently refrain from blood donation, as per current UK Blood Transfusion and Tissue Transplantation Services guidelines. 8. Reachable (24 hours a day) by mobile phone during the period between CHMI and completion of antimalarial treatment. 9. Willing to take a curative anti-malaria regimen following CHMI. 10. Able to answer all questions on the informed consent questionnaire correctly at first or second attempt. 11. Willing to be registered on the TOPS database (The Over volunteering Prevention System; www.tops.org.uk). _____ Previous inclusion criteria: 1. Healthy adult aged 18 to 45 years. 2. Able and willing (in the Investigator’s opinion) to comply with all study requirements. 3. Willing to allow the Investigators to access participant’s electronic medical records and discuss the participant’s medical history with their GP. 4. Able and willing to provide written informed consent to participate in the trial. 5. Participants of childbearing potential only: must practice continuous effective contraception for the duration of the study. 6. Negative haemoglobinopathy screen (including screening for sickle cell disease and alpha and beta thalassaemia) and normal G6PD levels. 7. Agreement to permanently refrain from blood donation, as per current UK Blood Transfusion and Tissue Tra
Current exclusion criteria as of 10/09/2025: 1. History of clinical malaria (any species) or previous participation in any malaria vaccine trial 2. Planned travel to a clearly malaria-endemic locality during the study period or previous travel to a malaria endemic locality within the preceding six months. 3. Use of immunoglobulins or blood products (e.g. blood transfusion) in the last three months. 4. Receipt of any vaccine in the 30 days preceding enrolment, or planned receipt of any other vaccine within 30 days following each study vaccination, with the exception of COVID-19 and flu vaccines, which should not be received between 14 days before to 7 days after any study vaccination. 5. Receipt of a vaccine within 2 weeks before the day of CHMI or planned receipt of a vaccine prior to expected completion of antimalarial treatment (around 2 to 3 weeks after day of challenge based on experience in previous P. falciparum CHMI studies to date). 6. Receipt of an investigational product in the 30 days preceding enrolment, or planned receipt during the study period. 7. Concurrent involvement in another clinical trial involving an investigational product or planned involvement during the study period. 8. Prior receipt of an investigational vaccine likely to impact on interpretation of the trial data, as assessed by the Investigator. 9. Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV infection; asplenia; recurrent, severe infections and chronic (more than 14 days) immunosuppressant medication within the past 6 months (inhaled and topical steroids are allowed). 10. History of allergic disease or reactions likely to be exacerbated by any component of the vaccine. 11. Any history of anaphylaxis. 12. Pregnancy, lactation or intention to become pregnant during the study. 13. History of cancer (except basal cell carcinoma of the skin and cervical carcinoma in situ). 14. History of serious psychiatric condition that may affect participation in