A Brazilian vaccine against the most common type of malaria in the country and in regions of the Americas is in the patent phase [processo administrativo para obter um título de propriedade temporária] and by January the request for human testing must be filed with regulatory agencies. The immunizer against Plasmodium vivax went through the pre-clinical phase to evaluate quality, efficacy and safety, with promising results.
There is currently no vaccine against malaria vivaxinfectious disease caused by the parasite of the genus Plasmodium and transmitted to humans by the bite of female mosquitoes Anopheles. There are three most common species of the parasite in Brazil – vivax, falciparum and malariae. Only against the second has the World Health Organization (WHO) recommended, since 2021, vaccination in children in some sub-Saharan African countries.
“We have an unprecedented product in the world and entirely produced in Brazil. My goal since the beginning of the research, more than ten years ago, was to obtain a vaccine. Now we are in the final stage for authorization of clinical studies”, says professor at the Faculty of Pharmaceutical Sciences of the University of São Paulo (FCF-USP) Irene Soares, coordinator of the work, together with professor Ricardo Gazzinelli, director of the Center for Pharmaceutical Technology. Vaccines (CT-Vacinas) and coordinator of the National Institute of Vaccine Science and Technology (INCT-Vacinas).
Soares receives support from FAPESP through a Thematic Project. The group also received funding from the National Council for Scientific and Technological Development (CNPq, INCT-Vacinas 465293/2014-0) for initial proof-of-concept studies and from the Studies and Projects Financier (Finep, agreement 01.22.0046.00) to carry out the phase 1 clinical trial.
Called Vivaxin, the vaccine underwent good laboratory practice (GLP) and manufacturing (GMP) testing. It was presented in September during the 2nd Innovation and Sustainability Congress of the Belo Horizonte Technological Park (BH-TEC) by CT-Vacinas from the Federal University of Minas Gerais (UFMG), USP’s partner in developing the product.
“In Brazil, there is a large gap in vaccine research lines, which became evident during the Covid-19 pandemic. Basic research is normally carried out in academia, which involves the definition of antigen, adjuvant and proof of concept. From then on, articles are published and studies are discontinued, not reaching the vaccine. The objective of this partnership is to overcome the ‘valley of death’ and have the final product, for testing on humans, in a process entirely developed in the country, a rare fact in Brazilian science in the area of vaccines”, says Soares to FAPESP Agency .
The patent application was made at the end of October through the USP Innovation Agency and the UFMG Technological Transfer and Innovation Center. The patent protects the production process and final formulation with adjuvant developed by the CT-Vacinas team. The results of the latest tests should soon be published in a scientific journal.
Furthermore, researchers had already demonstrated, in article published in April in Vaccinethat the vaccine was able to induce high levels of antibodies in mice and rabbits, proving to be safe and well tolerated. The presented formulation combines in a single molecule three different genetic forms, the so-called allelic variants, of a protein from Plasmodium vivaxPvCSP (circumsporozoite protein), with the aim of increasing effectiveness and protecting against all variations.
Unlike the parasite falciparum (more common on the African continent), the target protein of vivax has three allelic forms –VK210, VK247 and P. vivax-like. It became a target because it is the most abundant component on the surface of sporozoites – an elongated form of the parasite present in the salivary gland of the transmitting mosquito and which infects humans, contaminating the liver. It has an area that binds to cellular receptors and antibodies.
In the study with the new formulation, the antibodies produced by the immunized mice recognized the three variants, managing, in some cases, to completely prevent infection (sterile protection) and, in others, to delay the appearance of the parasites in the blood.
In recent years, scientists have tested some adjuvants to reinforce the action of the immunizer. One of these tests resulted in another article, also published in April, in the magazine Frontiers in Immunologywith support from FAPESP.
Considered endemic in the Amazon region and a global public health problem, malaria causes fever, chills, tremors, sweating and headache. In severe cases it leads to convulsions, hemorrhages and altered consciousness. Typically, the patient receives treatment on an outpatient basis, with pills provided free of charge by the Unified Health System (SUS).
From January to October this year, Brazil registered 117,946 cases of the disease, 80% of which (95,113) were caused by Plasmodium vivaxaccording to the Ministry of Health. A worrying situation has been detected among indigenous people – there were around 45,100 cases until September, an increase of 12% compared to the same period in 2023.
On the last World Day against Malaria, celebrated on April 25, the Pan American Health Organization (PAHO) asked governments to intensify efforts to combat the disease, which has a greater impact on indigenous peoples, migrants and populations in situations of vulnerability.
Last year, countries in the Americas reported around 480,000 cases of malaria. Although the number has been decreasing since 2017 (when there were 934 thousand registrations), some countries are still far from reaching the target of a 75% reduction by 2025.
The article “Non-clinical toxicity and immunogenicity evaluation of a Plasmodium vivax malaria vaccine using Poly-ICLC (Hiltonol®) as adjuvant” can be read on the ScienceDirect website.
And the study “Poly I:C elicits broader and stronger humoral and cellular responses to a Plasmodium vivax circumsporozoite protein malaria vaccine than Alhydrogel in mice“ is available on the Frontiers website.
This content was originally published in Malaria vaccine developed at USP may soon be tested on the CNN Brasil website.
Source: CNN Brasil