It is defined by the Center for Veterinary Biologics (part of the U.S. Department of Agriculture's Animal and Plant Health Inspection Service) as a "new hybrid microorganism created by joining nucleic acid fragments from two or more different microorganisms in which each of at least two of the fragments contain essential genes necessary for replication.
[citation needed] Chimeric flaviviruses have been created in an attempt to make novel live attenuated vaccines.
[2] In mythology, a chimera is a creature such as a hippogriff or a gryphon formed from parts of different animals, thus the name for these viruses.
[3] In 2012, the first example of a naturally-occurring RNA-DNA hybrid virus was unexpectedly discovered during a metagenomic study of the acidic extreme environment of Boiling Springs Lake that is in Lassen Volcanic National Park, California.
The US Food and Drug Administration (FDA) has recently approved the use of chimeric antigen receptor (CAR) to treat relapsed non-Hodgkin Lymphoma.