Biotechnology risk is a form of existential risk that could come from biological sources, such as genetically engineered biological agents. These can come either intentionally (in the form of bioterrorism/biological weapons) or unintentionally (through the accidental release of engineerer viruses). A chapter in biotechnology and biosecurity was published in Nick Bostrom's Global Catastrophic Risks, which covered risks such as viral agents. Since then, new technologies like CRISPR and gene drives have been introduced.
While the ability to deliberately engineer pathogens has been constrained to high-end labs run by top researchers, the technology to achieve this (and other astonishing feats of bioengineering) is rapidly becoming cheaper and more widespread. Such examples include the diminishing cost of sequencing the human genome (from $10M USD to $1000), the accumulation of large datasets of genetic information, the discovery of gene drives, and the discovery of CRISPR.
Pathogens may be intentionally or unintentionally genetically modified to change their characteristics, including virulence or toxicity. When intentional, these mutations can serve to adapt the pathogen to a laboratory setting, understand the mechanism of transmission or pathogenesis, or in the development of therapeutics. Such mutations have also been used in the development of biological weapons, and dual-use risk continues to be a concern in the research of pathogens. The greatest concern is frequently associated with gain of function mutations, which confer novel or increased functionality, and the risk of their release.
A group of Australian researchers unintentionally changed characteristics of the mousepox virus while trying to develop a virus to sterilize rodents as a means of biological pest control. The modified virus became highly lethal even in vaccinated and naturally resistant mice.