A Brazilian vaccine targeting the most common type of malaria in the country is nearing human trials, with the application to regulatory agencies expected by January 2024. The vaccine, developed against Plasmodium vivax, has shown promising results in pre-clinical testing for quality, efficacy, and safety.
Currently, there is no vaccine available for P. vivax, an infectious disease caused by the Plasmodium parasite, transmitted to humans through bites from female Anopheles mosquitoes. In Brazil, the three most common species of the parasite are vivax, falciparum, and malariae.
“We have a unique product in the world, entirely produced in Brazil. My goal from the start of the research over ten years ago was to achieve a vaccine. Now we are in the final stage for authorization of clinical studies,” said Professor Irene Soares from the Faculty of Pharmaceutical Sciences at the University of São Paulo (FCF-USP), who coordinates the project with Professor Ricardo Gazzinelli, director of the Vaccine Technology Center (CT-Vacinas) and coordinator of the National Institute of Science and Technology for Vaccines (INCT-Vacinas).
Soares receives support from FAPESP through a thematic project. The team also received funding from the National Council for Scientific and Technological Development (CNPq) for initial proof-of-concept studies and from the Financing Agency for Studies and Projects (Finep) to conduct phase 1 clinical trials.
Named Vivaxin, the vaccine has undergone good laboratory practice (GLP) and good manufacturing practice (GMP) testing. It was presented in September at the 2nd Congress on Innovation and Sustainability at the Belo Horizonte Technological Park (BH-TEC) by CT-Vacinas from the Federal University of Minas Gerais (UFMG), a partner of USP in the product's development.
“In Brazil, there is a significant gap in vaccine research, highlighted during the COVID-19 pandemic. Academia usually conducts basic research, defining antigens, adjuvants, and proof of concept. This often results in publications, but studies are discontinued before reaching the vaccine stage. The goal of this partnership is to overcome the 'valley of death' and have a final product ready for human testing, a rare achievement in Brazilian vaccine research,” Soares explained to Agência FAPESP.
The patent application was submitted in late October through the USP Innovation Agency and the Technology Transfer and Innovation Center at UFMG. The patent protects the production process and final formulation with an adjuvant developed by the CT-Vacinas team. Results from the latest tests are expected to be published soon in a scientific journal.
Additionally, researchers previously demonstrated in an article published in April in Vaccine that the vaccine was capable of inducing high levels of antibodies in mice and rabbits, proving to be safe and well-tolerated. The formulation combines three different genetic forms, known as allelic variants, of a protein from P. vivax, the PvCSP (circumsporozoite protein), aiming to enhance efficacy and protection against all variations.
Unlike the falciparum parasite (more common in Africa), the target protein of vivax has three allelic forms—VK210, VK247, and P. vivax-like. It became a target due to being the most abundant component on the surface of sporozoites—the elongated form of the parasite present in the salivary glands of the transmitting mosquito, which infects humans by contaminating the liver. It features an area that binds to cellular receptors and antibodies.
In the study with the new formulation, antibodies produced by immunized mice recognized all three variants, managing to completely prevent infection in some cases (sterile protection) and, in others, delaying the appearance of parasites in the blood.
Malaria, considered endemic in the Amazon region and a global public health issue, causes fever, chills, shaking, sweating, and headaches. In severe cases, it can lead to seizures, bleeding, and altered consciousness. Typically, patients receive outpatient treatment with tablets provided free of charge by the Unified Health System (SUS).
From January to October this year, Brazil recorded 117,946 cases of the disease, with 80% (95,113) caused by P. vivax, according to the Ministry of Health. A concerning situation has been detected among indigenous populations, with about 45,100 cases reported by September, marking a 12% increase compared to the same period in 2023.
On World Malaria Day, celebrated on April 25, the Pan American Health Organization (PAHO) urged governments to intensify efforts to combat the disease, which disproportionately affects indigenous peoples, migrants, and vulnerable populations.
Last year, countries in the Americas reported approximately 480,000 malaria cases. Although numbers have decreased since 2017 (when there were 934,000 reports), some countries are still far from reaching the goal of a 75% reduction by 2025.