Tests with DNA vaccine against Zika begin in April, says the studys coordinator in Minas Gerais, Rodrigo Correa-Oliveira

After pioneering in findings about the Zika virus effects, Brazil now invests in the diseases prevention with vaccine trials


Volunteer trials for the study in Belo Horizonte began in early April and to the moment, 20 people have been selected. The first five volunteers were vaccinated from April 23 to 25

While researchers in the whole world are looking for ways to protect against Zika Virus (ZIKV), the Minas Gerais Federal Universitys teaching hospital began tests with the vaccine named DNA vaccine against Zika. The clinical 2/2b phase study of the experimental vaccine against the infection will last for two years and will assess the vaccines safety and effectiveness. The experimental substance has been used in humans in the USA and the clinical trials was approved by the national and international ethics and regulatory agencies. Volunteers will be split into two groups, for vaccine and placebo, and randomly given three doses of the vaccine in the first two months, without anyone knowing what was given until the end of the study.

Researcher Rodrigo Correa-Oliveira, the study coordinator at Fiocruz-Minas, stresses the goals of the 2/2b phase are to assess the vaccines safety and effectiveness to protect against Zika (defined as any viral infection confirmation with any ZIKV symptoms), in adults and adolescents from 15 to 35 years-old. He expects this vaccine will create a specific response generating antibodies that react against the virus and neutralize it. However, the hopes of a large-scale vaccine production is still far from reality. We are still at an initial phase and we expect to have results, but the large-scale production will only begin if the 2/2b Phase of the clinical trials prove the vaccine is safe and effective to protect against Zika virus. This will be followed by Phase 3 with crucial effectiveness trials, which if confirmed, will then allow applying to the regulatory agencies and to mass production. Phase 2 trials are designed to last approximately three years, given that each volunteer will be followed for two years after vaccination, he says.

Still according to the researcher, the vaccine, produced from the virus genetic material, will produce antibodies able to create a response against the infection in an immunized individual. Unlike vaccines produced from the virus itself, this vaccine used the Phase 2/2b is a DNA vaccine. This means it does not have the entire virus, whether attenuated or dead. Since it does not have the entire virus, it is impossible to develop the disease from it. This means it is safer, since even if some people have any disease compromising their immune systems, the vaccine is still safe to be used, he says.

The study will take place simultaneously in 19 research centers throughout USA, Central and South Americas. In Brazil, besides the Belo Horizonte Clinics Hospital, the São Paulo University School Clinics Hospital (HCFMUSP) intends to attend 120 volunteers. At the Belo Horizonte center, initially 100 people will join the study. If there are evidences of Zika transmission, we may apply to enroll more people. Volunteer selection for the Belo Horizonte study began in early April, and up to the moment, around 20 people have been included. The five first volunteers were vaccinated from April 23 to 25, he says. In total, 2400 volunteers are expected to join the study.

Partnership between researchers from UFMG, George Washington University and Fiocruz-Minas

Dr. Rodrigo Correa-Oliveira, who is also Research and Biological Samples vice-president at Oswaldo Cruz Foundation/Fiocruz, explains the researchers from George Washington University (GWU) and Fiocruz Minas have a partnership and collaboration agreement for over 17 years to perform experimental vaccines clinical trials against tropical neglected diseases, as hookworms and schistosomiasis. This partnership also includes the development of a highly specialized laboratory and clinical team, as well as the necessary infrastructure to perform experiments with high-quality vaccines according to the Clinical Good Practices. The vaccine against Zika clinical trials sponsor contacted researchers at GWU to ask about their interest to host a phase 2/2b clinical trial, given their long-lasting partnership with the Brazilian group and the fact that Zika is a problem in Brazil. All these factors influenced the assay, he says.

The researcher acknowledges the importance to the institution and the Country of being selected by the sponsor, as well as by the GWU team to be a participant center in these multinational Phase 2 clinical trials. This evidences the reputation and experience built by our group in Fiocruz-Minas and UFMG for the last years, which made us a valuable asset for the Country and the Unified Health System (SUS), since it will be immediately benefited when trials are over and the vaccine made available for the population, he says.

Finally, asked if Brazil is ready to prevent new (un)known arboviral outbreaks in urban areas, the researcher said not to believe. In his opinion, pompous investments at all levels are needed, from basic research to development of fast diagnostics, both clinical and serological, as well as vaccines able to be used preventively and/or for treatment. It is fundamental to carry an epidemiological/population analysis very fast so we can accelerate our reaction capacity against any virus, known or unknown. These activities must be very well integrated, what means large investments, he weighs.