Viruses can be used to apply to many different things, and in contemporary speech, the terms virus and viral have literally spread to an application that is far wider than the original senses of the word. To gather more data on the contemporary applications to both terms, I analyzed collocates surrounding these node words in the Corpus of Contemporary American English (COCA), which is an excellent tool with many different sources of language data. The top noun collocates for virus include: aids, influenza, infection, hepatitis, flu, immunodeficiency, computer, and disease.
I also completed a collocates search of the term viral, and the top noun collocates include: infection, video, infections, load, hepatitis, and later other terms like marketing, particles, sensation, hit, and internet. A virus, though similar to a complex system, is itself not the same, whether it is a computer virus or a disease in a living organism. In the human immune system, viruses disrupt and dysregulate the immune system in a variety of ways that do not always trigger the host recognition of the viral invader in the immune system (Gack).
The term virus came to be associated with computers with work by Jon von Neumann in his paper “Theory and Organization of Complicated Automata” in the 1940s. The first actual virus that affected a PC occurred in 1986 and is known as the "Pakistani Brain” virus (Scientific American). Certainly the term virus as applied to a computer is a metaphor, because it is similar in terms of taking over control or negatively affecting a program, they also can spread quickly and self-replicate systematically, adapting through mutation (Scientific American). Mutation and adaptation are important qualities in complex systems, but this does not make viral phenomenon- on the internet or in the immune system complex systems themselves. In the example of internet articles or videos spreading and going viral, this is just an example of information spreading, which is not the result of a complex system. The results that follow and the ways that new information affects language and interactions between people is part of the complex system of language.
Gack MU. 2017. What viruses can teach us about the human immune system. PLOS Pathogens Journal.
Scientific American. 2001. When did the term \'computer virus\' arise?