Brazil's health regulatory agency, Anvisa, on Wednesday (Oct. 7) authorized the first human trials of a Brazilian-made vaccine against malaria. The candidate, called Vivaxin, was developed by researchers at the Federal University of Minas Gerais (UFMG), the University of São Paulo (USP) and the pharmaceutical company Cristália. It targets Plasmodium vivax, the parasite behind most malaria cases in Brazil, according to reporting by G1.
What the first phase will measure
The authorized study is a phase 1 trial, the earliest stage of testing a vaccine in people. It will enroll 48 healthy volunteers aged 18 to 59 who have never had malaria, at UFMG's Hospital das Clínicas in Belo Horizonte. Participants will be split into groups receiving different doses of Vivaxin or a placebo. The protocol calls for three shots, 28 days apart, with about a year of follow-up.
Researchers will track three things: safety (how often adverse reactions occur and how severe they are), whether the vaccine triggers an immune response against the parasite, and how the body reacts to each dose. This stage cannot determine whether Vivaxin prevents the disease; that answer depends on later studies with larger groups of participants.
What is confirmed so far: the candidate cleared preclinical testing and received regulatory approval to be tested in people. What remains preliminary: any conclusion about protection. Anvisa's authorization does not mean the vaccine is approved for sale or available to the public. According to G1, development could still take years, and moving on to phase 2 depends on the results.
Why vivax is the target
Two malaria vaccines are already recommended by the World Health Organization, RTS,S/AS01 and R21/Matrix-M, but both were designed against Plasmodium falciparum, the species dominant in Africa and linked to most malaria deaths worldwide. No approved vaccine exists for P. vivax, which concentrates transmission in Latin America and Asia. In the Americas, the parasite accounted for an estimated 63.1% of malaria cases in 2024. In Brazil, the disease is concentrated in the Amazon region.
Until a vaccine arrives, protection still relies on well-known measures. Anyone living in or traveling to transmission areas in the Amazon should use repellent and bed nets and seek care for any fever, even weeks after returning from a trip. Malaria diagnosis and treatment are free in Brazil's public health system, the SUS, and starting treatment early prevents complications. If Vivaxin proves safe and effective in the coming phases, it would still take years to reach the public.