What is virus?
Wikipedia says: A virus is a small infectious agent that replicates only inside the living cells of other organisms. Viruses can infect all types of life forms, from animals and plants to microorganisms, including bacteria and archaea.
So basically, it is dead piece organic matter which has information coded in its dead DNA which can cause receiving cell to replicate the same copy of DNA urgently, rapidly, by keeping all other cellular tasks aside.
That is popular notion. The Sci-fi journalist’s notion.
In Biology, Virus is not enemy. Virus is the message. Extra-cellular material used for communication between cells of same organism or different organisms. It is vital environmental changes recording. Virus is one of the ways by which genetic information have adapted to survive in this biosphere. Viruses, unlike poisons, are capable of evolving genetically and going extinct to. They are actually helping organisms to establishing mutually benefiting relationships with their hosts.
Then why cells ill-behave, replicate them and the overall situation becomes deadly? Like HIV or Ebola?
Let me give you example:
There is one postman in the village. He brings telegram for several blood relatives living in same village. The message is a threat warning about possible attack by Daku(s) in all nearby villages. It is from distant relative living in different village.
Note: postman delivers this message to different homes. Same messages to different relatives for whom message was broadcast by distant relative.
Family 1 reads the message and immediately react! Some of them go to neighbors and inform them (Replication of information). Some faints after reading it.
Family 2 : Same responses as family 1
Family 3: As soon as they read, they are engaged in confrontation preparation. Some members also did what family 1 and 2 did.
In short, they all were occupied in alerting others in village and preparing self for worse possible future. Different families responded differently. Different cells respond differently. One common thing is: They all will inform others. To do that, they replicate messages i.e. proliferation of viruses.
Cells do not ill-behave. They do their job. They act as per their dharma. They adjust and help each-other to cope up with environmental stress. When Pranamay sharir is inefficient, many cells die (because this information generation is intense Prana-consuming activity). Sometimes organism die (HIV, Ebola, Flu).
Solution for viral infection is not killing viruses but correcting the environment. Environment immediate outside the cell and macro form of environment.