The use of compositions comprising a papaya mosaic virus (PapMV) moiety for stimulation of the innate immune response is provided. The PapMV moiety may be papaya mosaic virus or PapMV virus-like particles (VLPs). The PapMV compositions stimulate a sufficiently strong innate immune response to provide protection against subsequent pathogen challenge or to treat an established infection. The use of PapMV compositions to protect a subject from potential infection by a pathogen, such as a viral pathogen, a bacterial pathogen or a fungal pathogen, and the use of PapMV compositions to treat an established infection, are also provided. The PapMV compositions be administered, for example, via intranasal or pulmonary routes to elicit effects within the mucosa and/or in the respiratory system.
