HUNAnon ID: 3d72a1 March 21, 2018, 1:26 p.m. No.747061 🗄️.is 🔗kun >>7164 >>746813 Mumps vaccine does not wear off. There is no such thing as vaccine wearing off. Your immune system remembers that virus, that's it. If you catch mumps that mean this is a mutated new form of the original agent.