Júlio Pedrosa (Fiocruz Amazônia)
The Leônidas & Maria Deane Institute (Fiocruz Amazônia), in a partnership with the Tropical Medicine Foundation (FMT), is participating in a pre-clinical trial project for a vaccine against the vivax variety of malaria. The project has just had its sponsoring approved by the Global Health Innovative Technology Fund (GHIT) of Japan. The research is coordinated by researcher Shigeto Yoshida, of the University of Kanazawa, and its partners are, in addition to Fiocruz Amazônia, the universities of Hokkaido, Kyoto, Toyama, and the Jichi Medical University, in Japan, as well as Cambridge University, in the United Kingdom.
Fiocruz Amazônia participates in a pre-clinical research project for a vaccine for vivax malaria
According to Stefanie Lopes, vice-director for research at Fiocruz Amazônia and local coordinator of the studies, the Foundation currently relies on a platform that focuses on clinical trials for the testing of substances, as well as on new formulations for vaccines against malaria caused by Plasmodium vivax. This platform can evaluate ex vivo antimalarial activity against the blood stage of the parasite, as well as its activity in blocking the transmission of the parasite to the vector in in vivo studies, through the experimental infection of colonized Anopheles mosquitos”, explains Lopes. In the near future, the researcher should also be expanding the platform with the in vitro study against the hepatic stage of the parasite, currently under validation.
Lopes highlights that establishing this last trial relied on the support of the Medicines for Malaria Venture (MMV) and the Foundation of Support to Research in the State of Amazonas (Fapeam). “This is a very important work, as one of the main challenges to control malaria vivax resides in the existence of a latent stage in the liver, the hypnozoite, responsible for making the disease reappear without the need for a new bite by an infected mosquito”, she said, adding that the drugs available to attack this stage of the parasite, primaquine and its single-dose substitute, tafenoquine, cannot be widely used due to their side effects in certain groups of people, such as pregnant women and people with G6PD deficiency.
Most cases of malaria in Brazil are caused by Plasmodium vivax, and due to the absence of a long-term stable culture, trials such as these in the Fiocruz Amazônia platform can only be carried out in endemic areas of the disease, as they depend on collecting blood from volunteers with the disease. For Lopes, incentives to research are crucial not only for Brazil, but for all other countries affected by malaria. “The city of Manaus has become a promising center for trials, because malaria patients are seen by doctors on a daily basis, and our installed infrastructure makes it possible for these tests to be carried out”, she observed, mentioning that it is necessary to collect samples from infected humans in order to study them.