Reflections from Switzerland

text and photos: Tulio de Oliveira

I recently traveled to Switzerland to attend and present at the Emerging Virus Diseases Symposium in Geneva, held from April 7–10. Following that, from April 10–12, I visited collaborators and delivered a keynote lecture at the University of Zurich. In the following paragraphs, I share my reflections on this significant scientific journey, which took place at a time when the U.S. administration announced major cuts to USAID and NIH funding, and the World Health Organization (WHO) faces a drastically changing global health funding environment.

The symposium opened with a keynote and public lecture by Dr. Maria Van Kerkhove, a colleague and friend, and a prominent figure in global health. She currently serves as Acting Director of the Department for Epidemic and Pandemic Threat Management at WHO. In her presentation, she emphasized the major advancements in global health surveillance, including the early identification of viral variants such as SARS-CoV-2 Omicron, the Mpox clade Ib, and new Marburg virus genomes. She also outlined strategies to strengthen pandemic preparedness. However, during her speech, she grew visibly emotional as she spoke about the difficult situation WHO is currently facing—having to downsize between 30% to 60% of its staff if financial support does not improve. After her presentation, Dr. Van Kerkhove approached me to discuss how research teams in the Global South—such as CERI and KRISP—are increasingly vital in supporting genomic surveillance and the early detection of emerging pathogens.

The second keynote, delivered by Prof. Melanie Saville from PATH (UK), addressed the importance of focusing research on entire viral families to enhance immunogen discovery and vaccine development. She highlighted families such as Arenaviridae (including Lassa fever), Filoviridae (with Zaire and Sudan Ebola viruses, and Marburg virus), Nairoviridae (with Crimean-Congo Hemorrhagic Fever), and Togaviridae (which includes Chikungunya virus). Prof. Saville emphasized the need to apply diverse computational tools to accurately predict immunogenic targets, adjuvants, and immune modulators. She also discussed progress in mRNA-based vaccine platforms, including Self-Amplifying RNA (saRNA), Trans-Amplifying RNA (taRNA), and Circular RNA for Chikungunya vaccine development.

One of the most promising strategies involves creating vaccine libraries and identifying appropriate receptors in animals and humans. These are then used to guide immunogen design, cloned into cDNA constructs, tested in preclinical platforms, and eventually assessed in clinical trials for safety and efficacy.

Following the keynote addresses, the symposium Following the keynote addresses, the symposium continued with a session on Switzerland’s pandemic preparedness program. Six speakers contributed to this segment, and what stood out was how efficiently Swiss scientists collaborate. They demonstrated that a successful pandemic response plan isn’t only about drafting comprehensive documents, but also involves clear communication, securing a reliable supply of reagents and biologicals, and ensuring the availability of trained personnel.

The afternoon sessions focused on arboviruses—viruses transmitted by mosquitoes. The session began with a perplexing clinical case: a patient in Switzerland, immunocompromised and hospitalized with meningitis, was eventually diagnosed with West Nile virus after PCR testing of plasma and cerebrospinal fluid. Following treatment with Remdesivir, the patient cleared the infection, later developing a rash and hepatitis but ultimately recovered. This case illustrated how challenging it can be to diagnose rare viral diseases outside their typical endemic regions.

Another presentation discussed the rapid spread of Aedes albopictus mosquitoes in France, with over 10,000 cases of Chikungunya reported weekly in Réunion Island during April. The outbreak subsequently spread to Mayotte, Mauritius, and Seychelles, with more than 100 imported cases per week detected in mainland France. The rise in Chikungunya and West Nile virus infections across Europe is increasingly linked to climate change, which is enabling arboviruses to expand into new territories.

The first day of the symposium concluded around 9 p.m., featuring over 12 hours of intense presentations and discussion—an effort to make the most of the gathering of around 100 of the world’s leading virologists. That evening, sessions also addressed the rise in Enteroviruses since the COVID-19 pandemic. The session was led by Prof. Heli Harvala, who recently returned to Finland after two decades in Oxford. Enteroviruses, a broad family with over 100 lineages (grouped into types A–D), were discussed in depth. One of the key viruses was Coxsackievirus A6 (CVA6), which emerged in Finland in 2009 and has since spread across Europe. Infections rose rapidly after 2010, affecting nearly the entire population.

Another important virus discussed was Enterovirus D68, which emerged in 2014 and has been associated with a polio-like illness called acute flaccid myelitis. That year, the U.S. and Canada reported over 1,100 cases and 58 deaths. Since then, D68 has spread widely, becoming more pathogenic. The family also includes polioviruses, and although polio has been nearly eradicated thanks to vaccines introduced in the 1950s, declining vaccination rates led to a case of circulating vaccine-derived poliovirus type 2 (cVDPV2) in the U.S. in 2022. Prof. Harvala warned that if immunization efforts continue to weaken, new enteroviruses—such as a hypothetical “Enterovirus X”—could emerge and trigger future global outbreaks.

Day Two: Respiratory and Poxviruses

The second morning session focused on respiratory viruses, which pose a significant pandemic threat. One of the highlights was a compelling presentation by Prof. Marion Koopmans from Erasmus University in the Netherlands. She presented data on a zoonotic H5N8 vaccine developed and tested at Erasmus MC, showing strong cross-reactivity with H5N1 strains. The vaccine is based on an H5N8 strain with hemagglutinin (HA) closely resembling that found in recent H5N1 infections in Texan cattle, and showed promising reactivity against clade 2.3.4.4b H5N1 viruses.

The next segment addressed poxviruses, particularly the re-emergence of Mpox. Since the end of smallpox vaccination in Africa, Mpox cases have risen, especially in Central African forest regions. The clinical presentation closely resembles other poxviruses, often resulting in bacterial superinfections and complications such as blindness. Initial Mpox outbreaks mostly affected children, but between 2017 and 2019, it reappeared in Nigeria. While the first cases involved children, the virus eventually entered sexual transmission networks, particularly among MSM, leading to a global spread of clade IIb.

Although Mpox is a DNA virus, it is evolving at an unusually fast rate—about 28 times faster—more similar to RNA viruses. A surge of cases occurred between 2023 and 2025. Surprisingly, some of the recent outbreaks were linked not to clade IIb, but to clade I. In Eastern DRC, a novel variant—clade Ib—was identified, showing a high number of APOBEC-mediated mutations and adaptations to human-to-human transmission.

Day Three: Hemorrhagic viruses

The sessions started with strategies for identifying viral spillovers with the case of Nipah virus in Bangladesh was presented by Prof. Emily Gurley from the Johns Hopkins Bloomberg School of Public Health. Human infections with Nipah virus are rare and typically originate from contact with infected bats, pigs, or horses. Although person-to-person transmission can occur, it is relatively limited (with an R0 of less than 1), which makes widespread outbreaks unlikely. Nevertheless, due to Nipah’s high mortality rate and the close contact between humans and a range of domestic animals, the potential for spillover events remains significant. The hemorrhagic fever sessions also highlighted the recent Marburg virus outbreak in Rwanda. In 2024, the country experienced its first known outbreak of Marburg virus disease, which led to 66 reported cases and 15 deaths. The majority of infections occurred among healthcare workers in Kigali. The outbreak was initially challenging to contain and began spreading within a hospital ward. However, through active case detection, isolation efforts, and the use of a new vaccine supported by CEPI, the spread was eventually brought under control. The outbreak was officially declared over on December 20, 2024, following a 42-day period with no new confirmed cases.

Reflections:

Reflecting on this important scientific symposium and my interactions with nearly one hundred of the world’s top virologists, I am deeply aware of the turbulent state of the world. Climate change, environmental degradation, rapid urbanization, the rise of nationalism, and shrinking international funding are all converging to increase the risk of emerging viruses and epidemics. As countries become more isolated and less cooperative, the emergence of new pathogens becomes more likely. In many cases, even when surveillance systems exist, emerging threats may be ignored or hidden—either due to misinformation, disbelief, or a reluctance to take responsibility for the consequences of disclosing new scientific discoveries.