The recent mumps outbreaks among MMR vaccinated persons have raised questions about the biological mechanisms related to mumps symptoms and complications in the background of waning immunity. Contrary to other paramyxoviruses, the understanding of mumps virus pathogenesis is limited, and further in-depth clinical studies are required to provide answers to important research questions.
Keywords: MMR vaccination; Mumps virus; T cell immunity; mucosal immunity; orchitis; parotitis; symptoms; viruria.