A novel antibody treatment reduces deformed wing virus loads in the western honey bee (Apis mellifera).

The deformed wing virus (Iflavirus aladeformis) (DWV) is a key driver of colony loss in the western honey bee (Apis mellifera). Here, we demonstrate that orally delivered anti-DWV antibodies can act systemically to reduce DWV loads in naturally infected honey bees. Immunoglobulin Y (IgY) was produced in adult chickens against two DWV proteins, harvested from their eggs, and fed to bees in a sucrose solution. An enzyme-linked immunosorbent assay demonstrated that orally delivered anti-DWV IgY migrated to the hemolymph. We next assessed the ability of orally delivered anti-DWV IgY to reduce DWV viral loads in naturally infected bees using qPCR. An antibody treatment resulted in a significant eightfold viral load reduction in DWV-infected bees. Our findings demonstrate the potential for antibody treatments to help mitigate the losses attributed to DWV in A. mellifera.

Importance: Deformed wing virus (DWV) is considered to be a key component of declining honey bee health which threatens global food production. The virus can result in significantly shortened lifespan, deformities in developing bees, and impaired cognition. There is currently no method to directly control the virus. The virus can be indirectly controlled with acaricidal treatments that target a key vector, the parasitic varroa mite (Varroa destructor). But acaricide resistance and a lack of effective alternatives for the control of both Varroa and DWV are major threats to beekeeping and the wider agricultural industry. Our research presents a significant development in the ability to reduce DWV burden in honey bees using IgY antibodies. Moreover, immunoglobulin Y has the potential to be more broadly established as a new treatment modality to combat other pathogens and parasites in A. mellifera.