====== Virus ======
A **virus** is a [[nucleotide]] sequence that can only replicate within a host [[organism]]. Viruses can infect animals, plants, and bacteria.

  * [[virus:International Committee on Taxonomy of Viruses]]


===== Viral Structure =====
A virus is made up or a core of genetic material, which can be either [[DNA]] or [[RNA]], that is surrounded by a [[capsid]] that gives it physical structure and protection in many environments.


===== Types of Viruses =====

  * [[Adenovirus]]
  * [[Coronavirus]]


===== Theories of Viruses =====
Since viruses do not replicate without hosts, there has long been debate about whether or not viruses are alive or should be considered their own [[kingdom]] of life.

==== Quasispecies Swarms ====
Because viruses are extremely small and even a small ecology of them may contain a spectrum of genetic variance, some scientists have begun to examine viruses at the group level of constitution.((December, 2011 | Samuel Ojosnegros et al | [[Virus Research]] (journal) | Quasispecies as a matter of fact: Viruses and beyond | [[https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC7172439/|doi: 10.1016/j.virusres.2011.09.018]]))
  * Dec 2011 - Quasispecies as a matter of fact: Viruses and beyond
    * Mutant spectra act as interacting sets of variant viruses subjected to group selection. 
    * The target of selection may be realized through complementing or interfering interactions. 
    * Cooperative interactions can modulate virulence in bacteria. 
    * Cellular heterogeneity lies at the basis of tumor progression. 
    * Prions become heterogeneous by accumulating protein-folding mutants.

===== Challenges in Studying Viruses =====
Viruses are challenging to isolate since they require cells for replication.((November 11, 2020 | Rachael Krishna | [[https://fullfact.org/health/Covid-isolated-virus/|The Covid-19 virus has been isolated many times]])) Viruses including [[viruses:rhinovirus]] and [[viruses:bovine diarrhea virus]] have been isolated, sometimes using intermediate tissue cultures.(([[https://www.sciencedirect.com/topics/immunology-and-microbiology/virus-isolation]]))

===== Pathogenic Viruses =====
Most scientists believe that a small portion of viruses are [[pathogenic]] to their hosts.

==== Medical Testing ====
  * [[virus:Testing for Viruses in Humans]]

===== Links to Sort =====
https://www.ncbi.nlm.nih.gov/labs/pmc/articles/PMC6797082/

https://journals.plos.org/plosgenetics/article?id=10.1371/journal.pgen.1008271

https://harvard2thebighouse.substack.com/p/understanding-covid-19-and-seasonal