At San Raffaele a clinical study to test a therapeutic vaccine against HIV

The vaccine, tested for the first time in Italy on humans, aims to lead to effective recognition of the HIV virus and control of the infection

The available antiretroviral therapies are effective and guarantee an excellent quality of life for people living with HIV infection, but a vaccine that can control the infection is not yet available.

This is why the Viral Evolution and Transmission research teams, directed by Dr. Gabriella Scarlatti, and the Infectious Diseases Unit team, led by Prof. Antonella Castagna, have started a randomized controlled phase I clinical trial targeting people living with HIV to test the safety profile and level of immune response of a new vaccine, HIVconsvX, for potential therapeutic purposes.

The vaccine is provided by Professor Tomas Hanke of the Jenner Institute at Oxford University and has already been tested previously, with encouraging results, in volunteers without HIV infection.

"There are 85.6 million people living with HIV worldwide, and of these 160,000 in Italy alone, where new infections diagnosed in 2022 are about 2,000.

AIDS and HIV infection are far from gone. The search for new treatments, including vaccines, is therefore an absolute priority of the international scientific community".

states Dr. Scarlatti.

To date, the antiretroviral drugs available are able to successfully block the replication of the virus and make its presence in the blood undetectable, making the life expectancy of a person living with HIV comparable to that of the general population.

However, antiretroviral therapies - even if they are long-acting drugs that can be administered at long intervals - must be continued throughout life.

“Their interruption induces, in most cases, a viral rebound, i.e. a reappearance of the plasma viral load within 3-4 weeks”

says Prof. Castagna.

In addition to requiring rigorous adherence for their effectiveness, further problems lie in the possibility of side effects linked to the long duration of intake. Not least, all of these therapies are difficult to access for populations in developing countries.

Due to its great variability and mutability, HIV eradication is difficult to achieve, but a therapeutic vaccine could promote long-lasting and effective control of the infection.

"Together with my research group, we believe that this and similar research to ours can outline valuable opportunities for the long-term clinical management of people living with HIV, improving their well-being and quality of life, not least in populations that do not have ongoing access to drugs."

- concludes Gabriella Scarlatti.

The San Raffaele HIV-CORE007 study plans to enroll 33 HIV-1 positive volunteers (≥18 years and ≤60 years) who started antiretroviral therapy early with a stable regimen for at least 3 months and who have stably controlled the HIV infection at least 2 years.

In the first part, a phase I, randomized, single-blind study will be conducted to evaluate the safety profile of the new vaccine administered intramuscularly a first time and then a second time after 4 weeks.

A second part of the study aims to test the immunogenicity, i.e. the level of the immune response, of the vaccine and its ability to control the virus. The study is therefore randomized to receive the vaccine regimen or a placebo.

HIVconsvX is a mosaic vaccine created for a wide range of HIV-1 variants, potentially applicable to different HIV strains in any geographic region. Raffaele Dell'Acqua, infectious disease specialist and principal investigator of the study, states:

"We hypothesize that this vaccination regime is able to enhance the immune response against relevant sequences of the HIV genome and thus favor the control of replication."

HIV-CORE007 is the result of an international collaboration in which the immunogen was designed by Tomas Hanke. The project is part of the European AIDS Vaccine Initiative 2020 (EAVI2020) and also funded by the Ministry of Health.