"Coronaviruses include a group of RNA viruses of medical and veterinary importance, all of which are characterized by spherical, enveloped virus particles with prominent surface projections, resembling the corona of the sun. They infect various animal species, causing respiratory, gastrointestinal, cardiovascular, and neurological diseases. In humans, coronaviruses have been associated with common colds, diarrhea, and possibly multiple sclerosis. The prototypical coronaviruses include avian infectious bronchitis virus (!BV), mouse hepatitis virus (MHV), porcine transmissible gastroenteritis virus (TGEV), bovine coronavirus (BCV), human coronavirus (HCV), feline infectious peritonitis virus (FIPV), rat sialodacryoadenitis virus (SDAV), turkey coronavirus (TCV), rabbit coronavirus (RCV), and several viruses of other animal species."

"Hepatitis delta virus (HDV) contains a circular, viroid-like RNA genome, the only animal viral RNA of its kind. It possesses a ribozyme activity, which can autocatalytically cleave and ligate itself. The ribozyme has a unique structural requirement different from other known ribozymes."

"One scientific discovery is a gift from the accumulated work of hundreds of researchers. Collaboration is crucial because viruses are smarter than researchers."