June 13, 2025
Bulletin interne de l'Institut Pasteur
Interview with the leaders of priority area 2 "Environmental Transitions and Health"
In the lead-up to the Town Hall meeting due to take place on June 30, the senior management team and the Department of Communications and Public Affairs wanted to take this opportunity to introduce you to the scientists responsible for scientific priorities identified in the Strategic Plan, so you can find out more about their roles, the challenges entailed by their priority areas, key projects, and also upcoming events.
Interview with the leaders of priority area 2 "Environmental Transitions and Health"
Philippe Bastin
Head of the Trypanosome Cell Biology Unit
Anna-Bella Failloux
Head of the Arboviruses and Insect Vectors Unit
Arnaud Fontanet
Head of the Epidemiology of Emerging Diseases Unit
► Can you tell us about the scientific priority that has been assigned to you as part of the Pasteur 2030 Strategic Plan?
Arnaud Fontanet: Since the early 2000s, emerging infectious diseases (EIDs) have been multiplying. Over the past twenty-five years, we have witnessed about ten notable emergences; among them, I will cite seven that have been particularly impactful: the three due to new Betacoronaviruses - the SARS epidemic that originated in China in 2003, MERS in the Gulf countries in 2012, and COVID-19 seven years later - as well as H1N1 flu in 2009, the Ebola epidemic in West Africa in 2014, the Zika epidemic in 2015, and the mpox (formerly "monkey pox") epidemic in 2022.
The phenomenon of emergence itself, that is, the crossing of the species barrier by a virus from animals to humans (distinct from its dissemination within the human species, linked to exchanges and globalization), has become more frequent due to the combined effects of several factors: changes in hunting practices and the introduction of new animal species into markets - seen with civet farming to supply Chinese markets during the SARS emergence in 2003; the intensification of domestic animal farming, with the risks of new flu virus reassortment in poultry or pig farms; deforestation which disrupts the habitat of many animal species and brought Australian bats into contact with domestic horses, which were thus infected with the Hendra virus and transmitted it to humans. Climate change also plays a significant role by favoring the spread of certain vectors, such as Aedes mosquitoes (including the famous tiger mosquitoes).
The Institut Pasteur is a leading actor in the surveillance, understanding, and study of emerging infections, and the response to pandemics. Within priority 2 of the Pasteur 2030 strategic plan, I will be in charge of facilitating the work of researchers on campus who are interested in the conditions of these emergences and their link with environmental disruptions. An important part of the work will also consist of helping campus actors involved in the response to pandemics to prepare for the next one, as unfortunately there will be more.
Anna-Bella Failloux and Philippe Bastin: Arnaud described it very well; over the past three decades, many human pathogens have emerged through various transmission routes. This is especially the case for vector-borne transmission, which we study in conjunction with and in relation to the field of research on emergences. Climate changes are expanding habitats favorable to many vectors of pathogens, such as mosquitoes or ticks, increasing the incidence of diseases such as malaria, dengue, or Lyme disease in previously unaffected regions. We will focus on the study of diseases sensitive to climate change through the project of the future center dedicated to the study of these vector-borne diseases.
The plan to have a dedicated building for working on vector-borne diseases emerged from the Pasteur community as early as 2012. At that time, we found that we did not have the necessary infrastructure to work on these diseases, and we already perceived the effects of environmental and climatic changes, as well as the effects on the distribution of vectors.
This finding is even more relevant today as vector-borne diseases represent more than 17% of all infectious diseases, resulting in more than 700,000 deaths per year (WHO), particularly with malaria or dengue.
► How does the Institut Pasteur stand out from its competitors when addressing health issues in which the multi-factor element plays such a big role?
Anna-Bella Failloux and Philippe Bastin: There is no doubt that some of the diseases that are emerging or will emerge in wild outbreaks, following disruptions such as environmental or climatic changes, will be vector-borne. The pathogens are indeed viruses, bacteria, protozoa, and filariae studied by many teams on campus. The vectors belong to several groups of arthropods that we also study. We are fortunate that microbiologists and entomologists work together on the same campus at the Institut Pasteur.
The Institut Pasteur is the first in the world to have such coverage over the number of pathogens, the number of vectors, and multidisciplinary approaches. We cover the 25 pathogens identified by the World Health Organization (WHO) as being vector-borne. The Institut Pasteur is therefore very well positioned compared to its competitors and must initiate a dynamic by training and recruiting scientists in entomology to address vector-borne diseases.
The scientific strategy of the future center for the study of vector-borne diseases is continuing its development, and we have mapped the projects in the field of vector-borne diseases that will be integrated into the scientific program of this center. This represents about forty entities at the Institut Pasteur that work directly or indirectly on these diseases.
Medical entomology has been deeply rooted in the Institut Pasteur for a very long time, even becoming a tradition. In the early 20th century, two Institut Pasteur researchers, Alphonse Laveran and Charles Nicolle, both winners of the Nobel Prize in Physiology or Medicine, went to the field near the emergence zones in Pasteur Network countries to observe the sick and develop a strategy against malaria and typhus. During this period, courses and training for entomologists traditionally took place at the Institut Pasteur and ORSTOM (Scientific and Technical Research Office Overseas, now known as IRD for Research Institute for Development). The link was already very strong between the Institut Pasteur in Paris and the member institutes of the Pasteur Network due to the essential triad of basic research, surveillance, and fieldwork.
Charles Nicolle already warned us in 1933 that "there will be new infectious diseases. It is a fatal fact" (Destiny of Infectious Diseases). And today, we see that a non-negligible part of them is vector-borne.
Arnaud Fontanet: In response to the acceleration of emerging infectious diseases, we have the National Reference Centers (NRCs) in microbiology, the CIBU (Emergency Biological Intervention Cell), and collaborations within the Pasteur Network, which includes 32 members in 25 countries. The strength of the Pasteur Network, as mentioned by Anna-Bella and Philippe, lies in its vast multidisciplinary scientific expertise, advanced laboratories infrastructure, and global reach. Seventeen of its institutes are located in hotspots of infectious disease emergence, seven of which are in sub-Saharan Africa. These institutes play a key role in fighting epidemics and host national laboratories and WHO reference laboratories for major pathogens. They have been essential in managing epidemics such as Ebola (2014-2016), pneumonic plague (2017), Covid-19 (2020-2023), and mpox in Central Africa (geographically expanding since 2018).
Following the Covid-19 pandemic, we felt that we needed to learn from this major health crisis to be better prepared for the next one, which seems inevitable. We thus created the P3i initiative (Pasteur Pandemic Preparedness initiative), which is built around four pillars:
- Anticipating technical and personnel needs, and reflecting on management and logistics in case of a crisis. We also want to strengthen our ties with hospitals due to their central role in conducting clinical and translational research on emerging pathogens;
- Strengthening our surveillance and characterization tools for new pathogens through the NRCs and the CIBU;
- Our ability to develop biomedical countermeasures in case of a pandemic, including diagnostic tests and vaccines;
- The future center that will integrate the study of vector-borne diseases and will be operational in 2028.
We have also recreated the Task Force for investigating epidemic outbreaks (Outbreak Investigation Task Force - OITF), which had been launched after the Ebola epidemic in 2014, mobilized during MERS epidemics in the Gulf countries, central African Ebola epidemics, and the pneumonic plague epidemic in Madagascar in 2017. It had been put to sleep during COVID-19, and we have hiring an epidemiologist to reinstate it.
► How is your work organized?
Arnaud Fontanet: The coordination group for the response to COVID-19 (the "Task Force") that was set up during the COVID-19 pandemic under the coordination of Christophe d’Enfert has never stopped its activities. We continue to meet regularly, and we have expanded our team. It is within this group that the reflections on the preparation of the campus for the next health crisis continue. We have also set up working groups with researchers on campus concerned with the two current health crises, avian flu and mpox.
Anna-Bella Failloux and Philippe Bastin: We study all diseases related to parasites, viruses, or certain bacteria such as Lyme disease, malaria, sleeping sickness, leishmaniasis, Chagas disease, chikungunya, dengue, West Nile, and Usutu, etc.
Area 2 of the strategic plan is in line with the Labex IBEID (Laboratory of Excellence in Integrative Biology of Emerging Infectious Diseases), which is a scientific program grouping about fifty laboratories at the Institut Pasteur in partnership with Inserm, the French Agency for Food, Environmental, and Occupational Health Safety, the National Veterinary School of Alfort, the Assistance Publique - Hôpitaux de Paris, and Santé Publique France. This Labex aims to develop a structure to anticipate and combat emerging infectious diseases (EID). It has several programs to facilitate collaboration between laboratories and the emergence of young researchers at different stages of their careers. It also provides quickly mobilizable funds in case of the emergence of a known or less-known pathogen to react very quickly.
We also have another project related to the presence of ticks in urban areas that focuses on the development of a portable kit to quickly intervene and survey places where ticks may be carrying different pathogens.
It is important to note that vector-borne diseases are also related to urbanization and greening. With climate change, cities have warmed and implemented vegetation and water points to lower the temperature, but this attracts all insects and increases epidemic risks. Faced with these potential risks of dengue or chikungunya epidemics, we must remain vigilant and closely collaborate with our partners.
► Will you be involved in cross-cutting projects? If so, which ones?
Anna-Bella Failloux and Philippe Bastin: The strong connections we have with the Pasteur Network allow us to collaborate and share resources on a daily basis. The goal is to create a reference center for research on vector-borne diseases and climate changes.
We have also established collaborations with other organizations such as IRD (Research Institute for Development), CIRAD (International Center for Agricultural Research for Development), ANRS-MIE (ANRS Emerging Infectious Diseases), Inserm, Labex IBEID, and the Pasteur Network, thus highlighting the importance of fighting vector-borne diseases with the help of vaccination and antiviral treatments.
Arnaud Fontanet: We have just secured significant funding for a major cross-cutting project that allows us to participate in the response to the ongoing mpox epidemic in Africa. Indeed, the international health emergency declared by the WHO in August 2024 was renewed two days ago due to the epidemic's extension to West Africa. This project, which associates seven research teams from the campus with those of six Pasteur Network institutes in sub-Saharan Africa, will enable us to contribute to the evaluation of new molecular and serological tests, virus sequencing, and regional analysis of the circulation of new variants, as well as the characterization of these variants. All epidemiological and virological data generated by the project will be integrated into mathematical models to optimize the use of vaccine doses delivered in the concerned countries. This way, we will test "in real life" all the devices that have been set up in these countries following the COVID-19 pandemic to face a new pandemic.
►What is your goal for 2030 as head of scientific priority? What results do you intend to achieve?
Arnaud Fontanet: By working on current epidemics as we do with mpox, we are training ourselves to provide a better response to the next epidemics. But it is also important to reflect on what could be done upstream of the epidemics to prevent them. For this, we would need to have expertise in the ecology of infectious diseases to better understand the links between infectious agents and their environment. Let's see if we achieve this through recruiting or collaborating.
Anna-Bella Failloux and Philippe Bastin: What is essential for us is to be able to recruit and train a new generation that will take over the projects. The Institut Pasteur must remain in a dynamic of research and continue to strengthen its expertise in combating vector-borne diseases, anticipating and reacting to emergences, and collaborating with the Pasteur Network for coordinated action in the field.