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The therapeutic and preventive advances of the past four decades suggest a future without AIDS, although scientists and associations are still facing great challenges. Among them, the need to reduce the epidemic in Africa, the continent most affected by AIDS, to restore the population’s confidence in science, but also the need to develop a vaccine to slow down the transmission of the virus. On the occasion of the Sidaction weekend, Hélène Roger, director of analysis and advocacy, and Jennifer Pasquier, scientific director, return to these major issues in the fight against the disease.
A future without AIDS is taking shape in the near future thanks to many advances in terms of prevention and treatment. But these mainly concern Western countries. What about Africa today, which remains the continent most affected by AIDS?
Helen Roger: Africa is indeed disproportionately impacted by HIV since it accounts for two-thirds of people living with HIV, and more than half of new infections worldwide in 2021. Of the 10 million people worldwide who do not still do not have access to antiretroviral (ARV) treatment, 6 million live in sub-Saharan Africa. Children are the big ones forgotten since only a little more than one in two women receives treatment to prevent infection to the child during pregnancy, and only one in three children has access to treatment in West Africa. West and Center.
The question of young people is also central since it is in Africa that there are the greatest number of new infections among young people, and that HIV remains the leading cause of death among 10-19 year olds. The most excluded populations, and who are subject to penalizing and discriminatory laws, such as homosexuals, drug users or sex workers, are particularly vulnerable and have limited access to prevention and care systems. The lack of political will, the fragility of health systems, the absence of universal health coverage and the weak support for community actors are also combined with health and geopolitical factors – conflicts, insecurity, humanitarian crises and the very strong impact of the crisis. Covid – which make it particularly difficult to deploy appropriate responses.
Regarding Covid-19, Sidaction intends to “restore confidence in science, which was badly mistreated during the health crisis”. How does this constitute a major challenge for the association?
Jennifer Pasquier: The Covid-19 pandemic has sparked an increased interest in science among French people, while sometimes fueling their mistrust of certain uncertain or disagreeing experts. Yet science has had many successes in the fight against HIV over the past 40 years. Thanks to therapeutic and preventive advances, it is now possible to live an almost normal life with HIV. Armed with the fight against the virus, scientific research is one of Sidaction’s priorities. For 29 years, Sidaction has been the only association fighting AIDS to support medical and scientific research programs in France. Among the main issues, scientists are currently working on two major challenges: discovering a vaccine to slow down the transmission of the virus and finding a treatment to allow remission of HIV, which would allow patients to do without triple therapy. As 30 years ago with triple therapy, the community must mobilize to meet these scientific challenges.
Where exactly are we in the development of a vaccine against HIV?
Jennifer Pasquier: There are two types of vaccine: preventive vaccines which are administered to healthy people to prevent the onset of a disease of infectious origin and therapeutic vaccines which are administered to sick people to help their immune defenses fight the disease. . In the context of HIV, many trials have been conducted, but unfortunately have not yet resulted in the development of an effective preventive vaccine. The reason for this failure is multifactorial.
First, HIV is an RNA virus that transforms its RNA genome into DNA in the body. When it does, it makes a lot of mistakes, which are called mutations. This leads to a very high genetic variability, which means that there are a multitude of viral variants within the same individual, which allows him to evade the immune system. Then, there is no natural protective immune response identified for HIV: there is no cure for HIV, because the body is not able to develop an immune response capable of effectively protecting it from infection. It is therefore difficult to manufacture a vaccine without knowing exactly what type of immune response is needed to protect against infection.
As for therapeutic vaccines, they are designed to produce HIV-specific immune responses capable of controlling the virus after the interruption of antiretroviral treatment. Also called immunotherapies, these therapeutic vaccines could represent a complement, or even an alternative to ARVs. Different strategies are currently being studied, the biggest obstacle being that HIV integrates its DNA with that of the host, which complicates the task of the immune system.