On Tues 6 June, researchers vaccinated volunteers and began Mahidol University’s study of the malaria vaccine RTS,S/AS01. This is the first study in Asia of the vaccine, an advanced product that has received regulatory approval in Europe.
Several extensive clinical trials of RTS,S/AS01 have previously been conducted in children in sub-Saharan Africa. In a large Phase 3 trial of RTS,S/AS01E at 11 sites in seven sub-Saharan African countries, efficacy against clinical malaria in children aged 5–17 months following three primary doses was 45.1% (CI 41.4 to 48.7), 35.2% (CI 30.5 to 39.5) and 28.3% (CI 23.3 to 32.9) during 20, 32 and 48 months of follow-up, respectively.
While such a “leaky” vaccine is not ideal in high transmission settings, it could be useful in combination with other interventions such as mass drug administrations in the elimination of malaria in the Greater Mekong Subregion, leading malaria researchers say.
“RTS,S is the most advanced of the malaria vaccine candidates. This is the first time the vaccine is evaluated in an Asian population. If found to be safe and effective, RTS,S could be the urgently needed tool to expedite the elimination of malaria in the Greater Mekong Subregion,” said Dr Lorenz von Seidlein, Coordinator of MORU’s TME programme.
Expected to last 6 months, the Mahidol study will recruit 190 health adult volunteers to explore the immunogenicity and safety of various vaccine regimens with and without antimalarial drugs.
Funded by the Malaria Vaccine Initiative/PATH, the study is supervised by Mahidol Prof Sasithon Pukrittayakamee, Dr Borimas Hanboonkunupakarn and Dr Podjanee Jittamala and is coordinated by Pongphaya Pongsuwan. MORU investigators Sir Nick White, Nick Day, Arjen Dondorp and Lorenz von Seidlein will support the study implementation.