Hypermutation refers to a process where genes or DNA undergo extreme and rapid changes or mutations. It is like a super fast and intense version of regular mutation. Full definition
(D) The average number of somatic hypermutations in the pandemic H1N1 patient plasmablast variable region genes compared with primary IgG plasmablast responses to vaccinia (small pox) or the anthrax vaccine, or after at least 4 boosters with the anthrax vaccine. (jem.rupress.org)
Recent studies in mice suggested that antibodies produced by old individuals may be encoded by distinct immunoglobulin (Ig) genes and that the somatic hypermutation process in these individuals is compromised. (sens.org)
Another research group [16] used hypermutation in a similar way in Ramos cells to evolve mRFP1.2 (excitation / emission peaks of 590/612 nm) to mPlum (590/649 nm) and mRaspberry (598/625 nm). (journals.plos.org)