What is the term for a virus that has not been previously recorded?

The term for a virus that has not been previously recorded is "novel virus." This designation is used to describe viruses that are newly identified and have not been recognized or documented in scientific literature before. Novel viruses can emerge from mutations in existing viruses or from zoonotic events, where a virus jumps from one species to another, often leading to new strains that can pose health risks to humans or animals.

The concept of a novel virus is significant in virology and public health, especially during disease outbreaks, as it indicates that the scientific community may have limited knowledge about the virus’s characteristics, transmission, and impacts, making research and rapid response critical.