As influenza A viruses (especially the H3N2 subtype) continue to pose a significant public health threat during the winter months in Europe and the United States, the challenge of drug resistance in traditional antiviral drugs is becoming increasingly severe. Recently, a cutting-edge study from European academic institutions has brought a disruptive approach to influenza treatment. Scientists have successfully modified a cutting-edge phototherapy technology used in cancer treatment to create “near-infrared antiviral photoimmunotherapy,” achieving precise identification and efficient clearance of the influenza virus and its infected cells in the laboratory, opening up a new physical therapy pathway for combating seasonal influenza, including H3N2.
The Dilemma of Traditional Therapies and the Rise of Phototherapy Seasonal influenza causes hundreds of thousands of deaths globally each year, with the elderly and those with underlying medical conditions at the highest risk. Currently, the efficacy of mainstream clinical drugs in Europe and the United States, such as neuraminidase inhibitors, is highly dependent on administration within the “golden window” of 48 hours after symptom onset. Even more challenging is the high mutation rate of the influenza virus, which makes it highly susceptible to drug resistance, leading to drug ineffectiveness. Meanwhile, although antibodies targeting the viral surface hemagglutinin (HA) protein are an ideal treatment option, viruses can also evade recognition through antigenic drift.
Against this backdrop, the use of light as a physical means to combat infectious diseases is regaining scientific attention. Historically, light radiation has been used to combat bacterial infections and skin diseases. In recent years, different wavelengths of light, from ultraviolet and blue light to near-infrared light, have been shown to inactivate pathogens through mechanisms such as disrupting viral genomes or protein structures. However, achieving safe and precise targeting of viruses within the human body remains a core challenge.
Precise Modification of “Biological Missiles”: From Anti-Cancer to Antiviral The latest breakthrough research draws on “near-infrared photoimmunotherapy,” which has already achieved clinical success in the field of cancer. Its core principle is akin to equipping the immune system with “laser-guided missiles”:
Preparation of Targeted Carrier: The research team prepared a monoclonal antibody that specifically binds to the HA protein on the surface of the influenza A virus (the study used the H1N1 strain). Unlike neutralizing antibodies, this antibody does not directly inhibit viral activity but acts only as a precise “navigation head.”
Loading the photosensitive warhead: The antibody is chemically conjugated with a photosensitizer dye called IR700 to form an antibody-IR700 complex.
Perform photoactivated clearance: After the complex binds to free viral particles or virus-infected cells (whose surface highly expresses HA protein), near-infrared light of a specific wavelength is applied. The light energy induces a conformational change in IR700, generating localized mechanical stress at the binding site. This directly and physically destroys the integrity of the viral particles or causes rapid rupture of the cell membrane of infected cells, leading to leakage of contents and cell death.
This technology is named “Near-Infrared Antiviral Photoimmunotherapy” (NIR-AVPIT). Its greatest advantage lies in its extremely high specificity and novel mechanism of action: it does not interfere with the biochemical processes of the virus but rather physically destroys them, thus making it virtually impossible for the virus to develop drug resistance through conventional genetic mutations.
Laboratory Validation: Highly Efficient Inactivation and Clearance
This study validated the powerful efficacy of NIR-AVPIT in an in vitro cell model:
Direct Viral Inactivation: NIR-AVPIT treatment effectively neutralized the infectivity of free influenza virus.
Inhibition of Viral Spread: Treatment at the early stages of viral infection significantly inhibited viral replication and spread within the cell community. The study also found that two treatments at regular intervals produced a stronger inhibitory effect.
Significant Quantitative Effect: This therapy achieved a reduction of viral RNA amplification by more than four orders of magnitude (i.e., more than 99.99%), demonstrating its extremely high efficiency in clearing viral genetic material.
Precise Clearance of “Viral Factories”: The therapy rapidly induced morphological changes in cells expressing the HA protein and inhibited their proliferation, confirming its ability to precisely locate and clear infected cells that act as “virus production workshops.”
Although this study used the H1N1 strain as a model, it targeted the highly conserved HA protein of the influenza virus. Given that the H3N2 subtype also relies on the HA protein to infect cells, this therapy, in principle, has the same application potential, offering new hope for combating the variable H3N2 strains that often cause severe outbreaks.
Application Prospects and Challenges: From Laboratory to Clinical Practice
Phototargeting therapies, represented by NIR-AVPIT, bring multiple potential values to influenza prevention and control systems in Europe and the United States:
Overcoming Drug Resistance: Its physical destruction mechanism provides a novel approach to combating multidrug-resistant influenza viruses.
For High-Risk Patients with Severe Illness: It can serve as a supplementary or alternative therapy for immunocompromised patients, those who do not respond well to traditional drugs, or those who have missed the treatment window.
Reducing Viral Load: By rapidly clearing infected cells, it may help control disease progression and reduce the risk of severe illness.
Of course, moving this technology from the laboratory to mainstream clinical practice in Europe and the United States still faces challenges, including the production process of complex antibody-photosensitizer drugs, cost control, and how to optimize light equipment to ensure that light can safely, uniformly, and effectively penetrate human tissue to reach deep lung lesions. Currently, the parameters of phototherapy devices suitable for deep tissue treatment (such as wavelengths of 720-750nm) have been explored, but most commercially available home-use devices cannot meet the requirements.
Nevertheless, the scientific community is confident in this direction. As a review published in *eLight* points out, a deeper understanding of the mechanisms of light-virus interaction is driving the development of a new generation of antiviral tools aimed at achieving safer and more precise therapeutic interventions.
Conclusion From the ancient wisdom of sun healing to today’s molecular-level targeted photoimmunotherapy, humanity’s arsenal against influenza is undergoing a revolutionary evolution. The near-infrared antiviral photoimmunotherapy pioneered by European scientists not only provides a promising new candidate strategy for combating stubborn influenza viruses such as H3N2, but also heralds a potentially brighter era for anti-infective treatment—one that is highly efficient, precise, and less prone to drug resistance. With further research and technological advancements, this innovative therapy is expected to become an important part of comprehensive influenza treatment plans in Europe, the United States, and even globally in the future.
Post time: 12-10-25