An international study, coordinated by the Institute for Research in Biomedicine (IRB) in Bellinzona, has identified new human monoclonal antibodies capable of combating West Nile virus , a mosquito-borne disease that has become increasingly important in Europe and other parts of the world in recent years. The findings, published in the scientific journal Immunity , could represent a significant step toward developing new prevention and treatment strategies for this infection and other viruses belonging to the same family.

The study was conducted by researchers from the IRB, an institute affiliated with the University of Italian Switzerland (USI) , together with experts from Stanford University, Masaryk University, the University of Zurich, the Pasteur Institute in Novi Sad and doctors working in Serbia.

A growing health threat

West Nile virus (WNV) is transmitted primarily through the bite of infected mosquitoes. In most cases, the infection is asymptomatic or causes mild symptoms, but in some people it can develop into severe neurological conditions, with encephalitis, meningitis, and, in the most severe cases, potentially fatal consequences.

Despite the growing spread of the virus , there are currently no licensed vaccines for humans or specific antiviral therapies. This has prompted the scientific community to identify innovative therapeutic tools capable of limiting the disease.

The study starts with recovered patients

To better understand how the immune response works, the researchers analyzed blood samples from people who had recovered from the infection in Serbia.

The goal was to identify human monoclonal antibodies naturally produced by the body and evaluate their ability to neutralize the virus. In parallel, the study showed that the presence of neutralizing autoantibodies against type I interferons does not compromise the development of the antiviral antibody response, a finding that contributes to a better understanding of the immune mechanisms involved.

The contribution of the IRB of Bellinzona

The laboratory led by Davide Robbiani at the IRB played a central role in identifying the most promising antibodies.

Among those selected , W010 stands out , a monoclonal antibody that recognizes a specific site in domain III of the virus's envelope protein. This structure is essential for the pathogen to attach to cells and initiate infection.

In experimental mouse models, W010 has shown significant efficacy both when administered prophylactically, before exposure to the virus, and as a treatment up to five days after infection, maintaining its protective activity even in conditions of reduced functionality of the interferon response.

An antibody with an even broader action

The researchers also characterized a second monoclonal antibody, called W014 , which demonstrated the ability to neutralize not only West Nile virus but also several orthoflaviviruses responsible for neurological diseases.

These include Japanese encephalitis virus, Murray Valley encephalitis virus, St. Louis encephalitis virus, and Usutu virus, which are also vector-borne and have been associated, in some cases, with serious central nervous system infections.

This broad-spectrum capability makes W014 a candidate of particular interest in the development of future therapies directed against a broader group of encephalitic viruses.

New perspectives for vaccines and therapies

According to the authors, the results allow us to identify some of the most vulnerable points of the West Nile virus, offering useful indications for the design of next-generation vaccines.

The identified antibodies represent candidates for both preventative use and potential therapeutic treatments, in a context in which available options are still very limited.

The research also contributes to expanding knowledge of the neutralization mechanisms of orthoflaviviruses, paving the way for the development of shared strategies against infections that continue to pose a challenge to international public health.

The complete scientific publication is available in the journal Immunity at the following link:
https://www.cell.com/immunity/fulltext/S1074-7613(26)00224-4