image: Human cells infected with MPXV (in green) among non-infected cells (nuclei in blue). Confocal microscopy image. © Institut Pasteur / Mathieu Hubert and Olivier Schwartz
Credit: © Institut Pasteur / Mathieu Hubert and Olivier Schwartz
On Wednesday August 14, in response to the active circulation of clade 1 monkeypox virus (MPXV) in Central Africa and the recent expansion of a subtype (1b) thought to be more lethal and transmissible in East Africa, the World Health Organization (WHO) declared a public health emergency of international concern (PHEIC), paving the way for enhanced coordination between regional health systems and the active engagement of stakeholders to tackle this global outbreak. The following day, Thursday August 15, Sweden reported the first positive case of clade 1b mpox on European soil. This led the French government to place the French health system on maximum alert on Friday August 16, and the French authorities have now begun to re-evaluate the health recommendations established in 2022 during the previous mpox outbreak in preparation for the probable emergence of cases in the country.
In these circumstances, the Institut Pasteur is contributing to the national response by taking three immediate measures:
1. The Department of Public Health within the Ministry for Health has activated the Institut Pasteur's Laboratory for Urgent Response to Biological Threats (CIBU), and since the weekend, at the request of French health authorities, it has been analyzing samples taken from suspected cases at hospitals in Paris or at the Institut Pasteur Medical Center to establish an mpox diagnosis, in tandem with reference health care establishments and in conjunction with the National Reference Center – Expert Laboratory (CNR-LE) for Orthopoxviruses.
2. The Institut Pasteur Medical Center, which specializes in travel medicine (tropical infectious diseases, including skin conditions) and which treated mpox patients during the previous outbreak in 2022, has activated its internal protocol so that any patients with typical mpox symptoms who come for an appointment can be tested in conditions of optimal safety: samples are taken in an isolated negative pressure room and a tried and tested procedure for handling, packaging and transporting samples to a biosafety level 3 laboratory is applied. In the event of a positive test, patients will be treated in conjunction with reference health care establishments with which the Institut Pasteur works closely.
3. The Institut Pasteur Medical Center has informed the health authorities that it is available to vaccinate any members of populations targeted by the health recommendations on mpox (currently being revised), as it did in 2022, when it vaccinated more than 1,500 people at high risk of infection.
"With the active circulation of this new strain of mpox in several African countries and its recent emergence in Europe, it is likely that people in France will be affected. This is a serious health situation that requires us to be very vigilant. That is why the Institut Pasteur is responding actively, drawing on years of research on this virus and the experience acquired during the 2022 outbreak. We are ready to test and vaccinate patients at the request of the authorities, in application of the health protocol and in conjunction with reference health care establishments," said Institut Pasteur President Yasmine Belkaid.
The Institut Pasteur has also decided to step up the research that it has already been conducting for several years on mpox, especially in Central Africa, to help combat and curb mpox outbreaks over the long term.
• The aims of this research are to identify the animal reservoirs for the virus, its mechanisms of transmission from animals to humans and between humans, and the resulting epidemic dynamics. The expertise developed in this area is used by local health authorities to determine appropriate public health measures to tackle the spread of the virus.
• The research strengthens our diagnostic capabilities with the help of tests that can be used in the field and our knowledge of virus subtypes through sequencing. Current efforts in France and at international level to diagnose mpox and isolate the different circulating strains are benefiting from this research.
• Research is ongoing at the Institut Pasteur to bring about longer-term improvements to treatments and vaccines for the various strains of mpox. The Institut Pasteur is currently leading an extensive study to analyze the function of Tecovirimat, the main antiviral on the market, to determine its efficacy on the various circulating strains and identify additional drugs that may be active against strains for which Tecovirimat does not work. In collaboration with Inserm, the Institut Pasteur is also seeking to characterize novel monoclonal antibodies as well as "nanobodies," small antibodies with neutralizing activity against mpox, for use in antiviral therapies. Lastly, the Institut Pasteur is exploring avenues to improve existing vaccines (known as third-generation vaccines) or vaccines under development (messenger RNA vaccines) using its own antigens.
For the Institut Pasteur President, Yasmine Belkaid, "this new episode serves as a reminder that epidemic risk is unfortunately part of our lives and that tackling it requires a comprehensive, sustained, long-term response. Growing ecosystem disruption and the continued development of international trade and travel make this risk more pressing every day. We need to play our part by supporting scientific research on infectious diseases in the fields of virology, immunology and vaccinology, as well as epidemiology, ecology and anthropology, and working in the field to tackle disease outbreaks, especially in the Global South, enabling local populations and local and regional authorities to act with sovereignty and to prevent and manage this risk themselves."