A Phase I/IIa Clinical Trial to Assess the Safety, Immunogenicity and Efficacy of the Blood-stage Plasmodium Vivax Malaria Vaccine Candidate PvDBPII in Matrix M1 in Healthy Adults Living in the UK

Plasmodium vivax (P. vivax) is the second commonest type of malaria parasite and although does not cause as many deaths as the most common malaria, called P. falciparum, P. vivax malaria can still cause severe disease and even death in some cases.

This study will be one of the first to test whether a vaccine can prevent or slow vivax malaria infection. A safe and effective vaccine would significantly reduce the global health burden caused by P. vivax malaria but unfortunately, no vaccine is yet available.

15 healthy volunteers aged 18-45 will be recruited in England at the Centre for Clinical Vaccinology and Tropical Medicine, Churchill Hospital, Oxford. All volunteers will receive three doses of the PvDBPII 50ug/Matrix M1 50ug candidate vaccine at monthly intervals prior to blood-stage CHMI 2-4 weeks after the third vaccination. Volunteers will undergo blood stage CHMI with Plasmodium vivax. 2 further volunteers will be recruited to act as back-up volunteers who will be vaccinated but only undergo CHMI if there are any last-minute drop-outs from the CHMI group. Volunteers in a parallel study (VAC069), who will undergo the same CHMI without prior vaccination, will be used as infectivity controls. Participants will be followed for approximately 1 year.

Primary outcome: 1) To assess the safety  of the PvDBPII-Matrix M1 vaccine in healthy volunteers, 2) To establish whether the PvDBPII-Matrix M1 vaccine can demonstrate a reduced parasite multiplication rate in vaccinated subjects compared to infectivity controls in a blood-stage controlled human malaria infection model

Secondary outcome: 1) To assess the humoral and cellular immunogenicity of the PvDBPII-Matrix M1 vaccine candidate, 2) To assess immunological readouts for association with a reduced parasite multiplication rate

ClinicalTrials.gov Identifier:   NCT04201431
Study Phase:                        I/IIa
Study Type :                         Interventional
Intervention Model:              Single Group Assignment
Masking:                              None (Open Label)
Primary Purpose:                 Prevention

Clinical trial registration

P. vivax
Vaccines (Immune Correlates)

Jan 2020 — Nov 2021

United Kingdom

Towards a vaccine for Plasmodium vivax