IrsiCaixa prepares the start of clinical trials of therapeutic AIDS vaccine


  • The therapeutic vaccine designed by IrsiCaixa researchers is the very first one developed according to the immune response of people who control HIV without antiretroviral treatment. Phase I trials will begin in the upcoming months, after getting excellent results in animal testing 
  • Clinical batches that will be administrated to volunteers, are currently being produced. Clinical trials are also being designed for their approval by the Spanish Agency of Medicines and Health Products (AEMPS)
  • IrsiCaixa, promoted by the Obra Social "la Caixa" and the Health Department of the Generalitat de Catalunya, is creating a cohort of 150-200 people who treatment early after acute infection, as a platform to test therapeutic vaccines and eradication strategies
  • Today, May 18th, is the AIDS Vaccine Day 

Current antiretroviral treatments slow down the progression of HIV infection, but cannot eradicate the virus from the body. Nowadays, the most realistic strategy to eradicate HIV/AIDS is the development of an effective vaccine, and so therefore today, May 18th , we are celebrating AIDS Vaccine Day. The IrsiCaixa AIDS Research Institute, promoted by the Obra Social "la Caixa" and the Health Department of the Generalitat de Catalunya, has already started the regulatory process for clinical trials of its therapeutic AIDS vaccine, which is the first one designed according to the immune response detected in HIV-infected people who better control the infection in the absence of antiretroviral treatment. Phases I and II will begin after the good results recently published achieved in testing with mice and monkeys (Mothe et al, 2015 JTM).


“We have studied in depth how HIV behaves in thousands of infected people, and we have learnt which is the necessary immune response to better control the virus replication in the absence of antiretroviral treatment. This response is what we have incorporated into our HTI vaccine design", explains Dr. Beatriz Mothe, researcher of the Host Cellular and Genetic Immunity group. To design the vaccine, a screening of more than 1,000 patients was first performed to define the virus targets where the vaccine had to be directed, selecting the answers of those who better control the infection and do not develop the disease (known as 'elite drivers', they represent an excellent model of functional cure). Simultaneously, HTI design has been optimized in order to be effective against mutated virus.


This last point makes the difference between HTI and previous vaccine designs, which were based on classic designs that included HIV proteins in full or native form, without paying attention to the specificity or quality of immune responses developed by infected people who are able to control the infection.


Batches production and trial development 

Vaccine clinical batches are currently being produced in the optimum conditions to be used in human beings, and clinical trials are also being designed to be presented, before summer starts, to the Spanish Agency of Medicines and Health Products.


Human trials are expected to begin throughout 2016. The first phase will last one year and will test the vaccine safety and capacity to induce a strong and lasting immune response. The second phase will last between 1-1.5 years and will evaluate its effectiveness to get a functional cure, which is the vaccine ability to prevent the virus rebound after the antiretroviral medication withdrawal.


Creating a cohort

In this study, IrsiCaixa will evaluate the functional cure strategies in people who are already in ART, whether initiated at early stages of infection or beyond the initial months. In addition to working closely with the HIV unit of the Hospital Germans Trias i Pujol (Fight Against AIDS Foundation) in the HIV-infected people management and monitoring, IrsiCaixa has promoted the creation of Early_cART study for the creation of a prospective cohort of individuals who begin antiretroviral treatment on an early stage. This cohort will serve as a platform for testing the efficacy of vaccines and therapeutic strategies for eradication.


The main reason why ART doesn’t eradicate the virus from the body is the existence of viral reservoirs which remain dormant inside cells and react when the treatment stops. There is a growing evidence that the start of antiretroviral therapy during the initial weeks of infection (known as “acute infection period”) offers an opportunity to reduce these viral reservoirs size, restricting the virus ability to mutate and getting a better immune recovery, which could favor the response to therapeutic vaccines.


The cohort will be integrated by 150-200 people with demonstrated recent infection, who start antiretroviral therapy in the first 6 months after HIV transmission. For the creation of this cohort, IrsiCaixa works closely with BCN Checkpoint and other HIV and other sexually transmitted diseases community centers, in order to identify new HIV infections at very early stages.


HTI vaccine has been developed under the HIVACAT project. Integrated by IrsiCaixa and the Infectious Diseases and AIDS unit of the Hospital Clínic de Barcelona, HIVACAT investigates the development of the vaccine in coordination with Esteve, and is supported by “la Caixa”, the Fundació Clínic and the Health and Economy Departments of the Generalitat de Catalunya.