A method of producing a picornavirus-like particle (PVLP) in a plant is provided. The method comprises introducing a first nucleic acid and a second nucleic acid into the plant, portion of the plant, or a plant cell. The first nucleic acid comprising a first regulatory region active in the plant operatively linked to a nucleotide sequence encoding a polyprotein. The second nucleic acid comprises a second regulatory region active in the plant and operatively linked to a nucleotide sequence encoding one or more protease. The plant, portion of the plant, or plant cell is incubated under conditions that permit the expression of the nucleic acids, thereby producing the PVLP. A PVLP comprising the polyprotein is also provided.