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Malaria vaccine development: Recent progress, future challenges

Malaria vaccine development: Recent progress, future challenges. Christian Loucq, MD Director, PATH Malaria Vaccine Initiative All Party Parliamentary Group on Malaria and Neglected Tropical Diseases October 26, 2009. PATH Malaria Vaccine Initiative Mission and vision.

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Malaria vaccine development: Recent progress, future challenges

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  1. Malaria vaccine development:Recent progress, future challenges Christian Loucq, MDDirector, PATH Malaria Vaccine Initiative All Party Parliamentary Group on Malariaand Neglected Tropical DiseasesOctober 26, 2009

  2. PATH Malaria Vaccine InitiativeMission and vision To accelerate the development of malaria vaccines and ensuretheir availability and accessibility in the developing world A world free from malaria Established in 1999 as a program of PATH.Current donors: Bill & Melinda Gates Foundation,USAID, ExxonMobil Foundation, private individuals

  3. PATH: a catalyst for global health MVI: a global programof PATH

  4. Role of MACEPA • Many groups/organizations involved in the purchasing and distribution of bednets, few are measuring impact of the interventions • One of the important roles of MACEPA— supported the coordination of malaria M&E in Zambia • Partner in the development of the RBM MERG Malaria Indicator Survey (MIS) • Document and disseminate success stories

  5. PATH background • International nonprofit to help provide appropriate health technologies and vital strategies to improve global health and well-being • Particular focus on: • HIV, TB, and malaria (MACEPA and MVI) • Health technologies designed for low-resource settings • Safer childbirth and healthy children • Health equity for women • Basic protection of vaccines

  6. Why a malaria vaccine? • Malaria • 900,000 deaths • US$ 12 billion • 40 percent of public health spending • Control • Elimination / Eradication

  7. Why a malaria vaccine?

  8. Malaria 101 • A parasitic infection transmitted to humans through the bite of infected female Anopheles mosquitoes • Five Plasmodium sp. infect humans; falciparum and vivax cause the vast majority of clinical cases • Almost all serious disease/deaths are caused by P. falciparum malaria in children under 5 years of age

  9. Challenges to developing malaria vaccines Scientific: No vaccine is in human use against a parasite Malaria parasite has ~6,000 genes, many more than a virus How best to provoke immune response? How to predict a vaccine candidate’s success? Commercial: Limited market in developed countries Endemic countries mostly poor High-risk, high-level investment

  10. Where are we today? • World’s most clinically advanced vaccine candidate is RTS,S • Collaboration with GSK Bio (Belgium), 11 study centers (in seven African countries), and Northern institutions • Phase 3 trial now up and running in all seven countries, 10 of 11 sites

  11. RTS,S Phase 3 MAL-055 Clinical Research Sites IRSS - Centre Muraz Burkina Faso KHRC, Kintampo KEMRI/WRAIR – Kombewa KCCR, Kumasi KEMRI/CDC – Siaya Ghana KEMRI/Kilifi Kenya HAS, Lambaréné Gabon JMP, Korogwe, Tanzania IHDRC, Bagamoyo, Tanzania Tanzania KINTAMPO HEALTH RESEARCH CENTRE UNC, Lilongwe Malawi CISM, Manhiça Mozambique RTS,S project is MVI’s largest collaboration

  12. Where are we today? • A second vaccine approach approved for first-in-human trial in the United States • Sanaria Inc. seeks to replicate original experiment with irradiated mosquitoes

  13. How MVI works MVI partners to achieve its mission; success depends on the strength of its collaborations MVI is a non-profit vaccine investor. Partners include academia, government agencies, biotechs, pharmaceutical companies MVI identifies potentially promising malaria vaccine candidates and approaches, then… MVI systematically move candidates and approaches through the development process.

  14. MVI Portfolio *Selected projects

  15. MVI collaborators include…

  16. Goals in sight? • Vaccine goal for 2015 in sight • 50% efficacy against severe disease • Lasts more than one year • Another tool to achieve malaria control • Next-generation vaccine could be in the pipeline now • Higher efficacy, lasts longer than 4 years • Transmission blocking? • Key to malaria elimination, eradication

  17. Malaria vaccine community goal • By 2025, to develop and license a malaria vaccine that has a protective efficacy of more than 80% against clinical disease and lasts longer than four years BUT, • Could we do more?

  18. Goal: Malaria eradication

  19. What comes next? • Focus on questions to be answered

  20. Different types of vaccine target different stages of the lifecycle • Pre-erythrocytic vaccines • Blood-stage vaccines • Transmission-blocking vaccines

  21. Different types of vaccine target different stages of the lifecycle

  22. Transmission-blocking vaccines target the parasite in the mosquito—and mosquito itself

  23. Transmission-blocking vaccines • Goal: Interrupt lifecycle to reduce transmission • Strategies: 1. Block production of gametocytes (highly effective PE vaccine) 2. Block oocyst formation in mosquito (prevent transmission of the disease) • TBVs target transmission: • No direct, immediate benefit to vaccinee • Infections reduced due to reduced transmission (herd effect) 2 1

  24. A Primary 1st boost 2nd boost Nov 10 Dec 10 Jan 10 Feb 5 Feb 21 Mar 6 May 5 Time points of various bleeds from animals MFA with sera (1:2) from baboons immunized with CH-rPfs48/45 in Montanide ISA-51 # Doses % Blocking (MFA) Primary 93 + 3 (88–94) Boost 1 97 + 1 (95–98) Boost 2 (15d) 97 + 1 (95–99) Boost 2 (30 d) 97 + 1 (96–98) Boost 2 (3 mo) 97 + 1 (95–99) Chowdhury, DR. et al. PLoS One July 2009. 4(7):1–10

  25. MFA to evaluate transmission blocking antibodies • Cultured serum + gametocytes fed to starved mosquitoes through membrane • Count oocysts in midgut 1 week later. • Result: % oocyst reduction

  26. Vaccines: Critical component of coordinated eradication effort • Vector control • Insecticide treated bednets • Indoor residual spraying • Integrated vector management • Drug therapy • Vaccines

  27. Final thoughts… • Malaria eradication will not happen without vaccines • Funding for R&D —and introduction — is needed • CollaborationCoordinationCommitment

  28. Tomorrow…

  29. Thank You www.path.org www.malariavaccine.org

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