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In recent years, scientific research on HIV treatments has made significant advances, improving the lives of patients. But the number of contaminations remains high and no effective vaccine has so far emerged. Update with Gilles Pialoux, vice-president of the French Society for the Fight against AIDS (SFLS).
1er December marks World AIDS Day, a disease caused by HIV, which affects more than 38 million people worldwide. In a report released on Tuesdaythe United Nations warned of the progression of contamination with 1.5 million new infections detected in 2021 and 650,000 deaths.
Despite significant progress in treatment, now possible by injection, access to care remains very unequal throughout the world and there is still no vaccine against AIDS. Since the Covid-19 pandemic, a new messenger RNA clinical trial was launched, to find out if this technology can also protect against HIV.
Gilles Pialoux, head of the infectious diseases department at Tenon hospital (AP-HP) and vice-president of the French Society for the Fight against AIDS (SFLS), answers questions from France 24.
France 24: The human immunodeficiency virus (HIV) was discovered in 1983. How to explain that nearly 40 years later, despite technological advances, contamination figures remain as high ?
Gilles Pialoux: Since the discovery of the virus, science has advanced considerably and today we benefit from very effective treatments. TasP (Treatment as Prevention) allows HIV-positive people to lead normal lives and blocks the transmission of the virus, even in relationships without a condom. This treatment also allows pregnant women to avoid transmission of the virus to the child.
For those who are HIV-negative, PrEP (pre-exposure prophylaxis) is a very effective preventive treatment that protects against contamination. However, these treatments are still underused. In France, only 28% of men who have sex with men use PrEP despite representing 43% of new infections. In women, who account for 32% of infections, this figure drops to 4%. A real problem of awareness therefore persists on this disease. We must deploy more means to publicize developments in the fight against HIV.
There is also a screening problem. While disparities in access to testing persist around the world, Covid-19 has caused a dramatic setback. This health crisis has affected all countries, including those which paradoxically were little affected by the coronavirus, in Africa in particular. This decline in screening is due to confinements and the general feeling of fear, but also to logistical problems, such as the shortage of reagents which has affected laboratories. We carried out 950,000 fewer tests in France alone in 2020, a decrease of 13%. In 2021, we increased our testing by 8% but we have not yet managed to return to the level of 2019. HIV testing is now possible without a prescription in France, which is great news. But here again, this measure must be accompanied by effective information campaigns.
Several clinical trials have recently been launched – including that of Moderna which uses RNA technology, effective against Covid-19 – to develop a vaccine against HIV. Where are these studies and do they have a chance of succeeding? ?
While it is true that in several respects, Covid-19 has harmed the fight against HIV, it must be recognized that at the level of research, the pandemic has instilled new enthusiasm. The American laboratory Moderna has launched phase 1 trials to assess the immune response and the side effects of a vaccine based on RNA technology while taking into account the particularities of HIV. In France, the Vaccine Research Institute (VRI) has also launched a new innovative clinical trial.
This virus poses a major difficulty because it mutates enormously, in infected people but also during transmission as well as depending on the environment and regions. Many clinical trials have already been conducted to obtain a vaccine, but these have never exceeded 31% efficiency, which is very insufficient. If we managed to reach 50 or 60%, that would already be enormous progress. The advantage of RNA is that this technology is much easier to build and therefore saves time. Scientists have developed a consensus model, with one injection to prepare the immune response and then a second to boost it. It is nevertheless necessary to temper the enthusiasm because we are at the very beginning. Phase 3, which must confirm vaccine efficacy before marketing, will alone take between three and four years. [La phase 2 n’a pas encore été lancée, NDLR.]
Only one HIV vaccine clinical trial is currently in phase 3. This is the project Mosaicowhich should deliver its conclusions at the end of 2023.
A lot of work is also being done to promote and improve the taking of treatments. Can you explain to us these developments and the importance of this approach ?
This work aims to respond to a strong demand for relief from patients because treatment against HIV is a long-term treatment, which generates fatigue but which must absolutely be respected because the virus becomes more resistant in case of of oblivion.
We have managed to lighten the tritherapies, which can now be taken four days a week instead of daily administration. For a little over a year, two antivirals can now be administered by injection, once every two months. This treatment remains in the minority because it is still little known and it requires the use of a nurse. But it has the advantage of allowing greater discretion vis-à-vis the family and professional environment, and of avoiding the “reminder effect” of taking medication, which is complicated to live with on a daily basis. Other improvements are underway to develop a monthly or even half-yearly tablet or even develop the subcutaneous implant, which distributes the product for a year, on the model already used for contraception.
In addition to the practical aspect, these advances aim to make life easier for patients, in a context of strong discrimination. This is the case in France, where certain jobs such as those of policeman or gendarme remain prohibited for HIV-positive people, where it is sometimes more difficult to obtain insurance and therefore to access property and sometimes even to obtain appointments. you medical. Despite all these years of raising awareness, the subject of HIV remains taboo in society and fuels fears. Even within the medical profession, a malaise persists on this difficult and intimate subject. Too many professionals prefer to avoid it and do not encourage screening enough, which causes a loss of opportunity for their patients.