Where are we in the AIDS epidemic today?
Gilles Pialoux: In 2021, worldwide, 38.4 million people were living with HIV. If we look at the incidence data for that year, an estimated 1.5 million new infections and 650,000 deaths. So yes, these figures are in relative decline, but it is not spectacular.
In France, the data is not very good, amplified by the fact that it was insufficiently informed, the health crisis not helping: 41% of mandatory declarations were not made for multiple reasons, preventing the rise modes of contamination and the socio-demographic profile of newly screened people.
In 2021, we also note a stagnation in the number of diagnoses: 5,013, according to the latest figures from Public Health France, and an increase in the incidence on certain categories of the population such as young men born abroad and having relations sex with men, and trans people.
In France, screening has stalled because of Covid: we lost around 900,000 tests in 2020. There is a lack of a real major screening campaign even if, and this is good news, we have noticed a slight increase in screening in the first half of 2022. Finally, the last important marker concerns late diagnoses. Last year, 30% of new diagnoses were at the disease stage, which is a very poor figure.
Clearly, the Covid crisis has made the fight against AIDS invisible between the various confinements and bottled laboratories.
Today, what are the possible treatments in case of seropositivity?
G.P.: A great deal of progress has been made in the field, in particular with a panel of new molecules in development and several weight-reduction possibilities. I can cite the arrival of injectables and the couple of antiretroviral molecules, cabotegravir and rilpivirine. At Tenon Hospital, we have been experimenting with it for six or seven years. These injectables are part of the possibilities of simplification for HIV-positive patients: they then receive two intramuscular injections every two months that can be performed in the hospital and then in town. That said, the patient must be able to find competent nurses to perform this type of injection, which requires a little skill, and we help them with this.
On the list of other methods of therapeutic relief, note the ANRS-Quatuor trial, to which the three infectious disease departments of Sorbonne University contributed. This trial validates the possibility of taking triple therapies over four days instead of seven. With Quatuor, the patient takes his antiretroviral treatment intermittently instead of once daily.
Other molecules are in development. I will cite two interesting ones: lenacapavir and islatravir which will be developed in the form of monthly or semi-annual tablets, or even as a subcutaneous implant like hormonal contraception. This is expected within two to three years. These two molecules are also intended to be used in prevention...
So, where are we in prevention today?
G.P.: Regarding PrEP (pre-exposure prophylaxis), the effectiveness is indisputable, but the findings are mixed. Yes, it is an extremely effective tool. In Tenon, we were among the first since we started working in 2015 on the ANRS-Ipergay study of PrEP "on demand". This consists of taking two tenofovir/emtricitabine tablets 2 to 24 hours before risky sexual intercourse and then one tablet 24 hours and 48 hours after. At the last congress of the French Society for the Fight against AIDS, of which I am vice-president, we dealt with inequalities in access to this treatment. In France, women represent 32% of new HIV diagnoses, but only 2.5% of them have initiated PrEP since 2016. Ditto for immigrant populations.
In the Ile-de-France region, out of 16,000 "PrEPors", heterosexual women born abroad are only 1% to benefit from it. They are under-represented even though they may have partners at risk... There is a lot of work to be done in terms of access to prevention for these populations.
Why does the PrEP campaign focus on gay men?
In addition to being 100% covered by Social Security, PreP can be prescribed in community medicine.
G.P.: Logically, in France, PrEP has been promoted a lot among men who have sex with men because they represent a significant part of contamination. However, just over half of newly diagnosed people in France are heterosexual women and men.
To date, there has been no campaign on methods of prevention, on HIV screening, on that of STIs... While this screening is possible without a prescription and covered by health insurance, there is still a long way to go, even if many things are progressing, such as the trial of PrEP on post-exposure prophylaxis with antibiotics. To put it simply, it consists of taking two tablets of doxycycline 100 mg ideally within 24 hours and at the latest within 72 hours following an at-risk report. This antibiotic has already shown its effectiveness in preventing chlamydia and syphilis, but is not yet in national recommendations.
If PrEP is a success for men who have sex with men, it is not yet widely enough beyond this target, unfortunately, although it can be prescribed to all those who consider themselves to be at risk of HIV.
How can we know if sexual intercourse is at risk in concrete terms? And why not open PrEP to all sexually active people?
G.P.: The whole question is to estimate the part of the risk. Already, we can protect ourselves with condoms, be in a closed couple, get tested with a serological blood test... That being said, we notice that most couples do not do this and decide to remove the condom without being sure that the partner is HIV-negative.
To answer your second question: yes, PrEP should be open to anyone who feels at risk, especially since in France, on-demand PrEP is very developed. In addition to being 100% covered by Social Security, it can be prescribed by the local doctor.
Much has been said about how quickly a vaccine for COVID-19 was found. What about a possible HIV vaccine?
G.P.: We have seen a recovery in vaccine research in recent years, particularly with the French biotechnology start-up Diaccurate. The Moderna laboratory has also begun to experiment with an anti-HIV RNA vaccine.
If vaccine research is paved with good intentions, it also suffers from many failures. I personally started injecting candidate vaccines in 1992 for ANRS phase 1 trials when I was at the Institut Pasteur, it goes back as you can see! With hindsight, a single phase 3 trial, RV 144, carried out by scientists in Thailand between 2003 and 2009, showed a small effectiveness of an AIDS vaccine of around 31%, which is insufficient. Especially when compared to PrEP which protects up to 96%...
Do you think that one day we will be able to cure AIDS?
G.P.: It seems complicated to me... We really come up against the fact that this virus is integrated into the cell and that all attempts to get it out of said cell have failed so far.
We are more concerned with the management of a chronic disease than with its cure. There remains the hope of a functional cure, that is to say that those affected can do without treatment.
What are you working on at the moment?
G.P.: My team works on several themes: prevention and screening for STIs, and risk reduction for drug use in a sexual context.
We also want to expand the sexual health offer, especially for trans people who are in the process of being reassigned to Tenon Hospital. We are in the process of developing tools to reduce these risks, such as a smartphone application which would allow us to know what drug the user has taken, what they should do in the event of danger... This is an ANRS research project which is progressing well and which has just passed before the ethics committee.
