Thus copying DNA to RNA is like copying these printed lecture notes, word for word, comma for comma, in your own handwriting - they are transcribed. When the information in RNA is copied into Protein we call the process translation, meaning that these lecture notes are now being written in Russian or Swahili. The term used to describe the step of copying RNA to DNA is then reverse transcription, and the enzyme that does it is called reverse transcriptase. This reverse transcriptase is carried in the virus particle and when the virus enters the host cell, the reverse transcriptase immediately goes to work making DNA copies of the RNA and then sews these pieces of DNA into the host genome. The virus escapes the host cell by simply migrating to the surface and poking its' way out by what is called budding.
Influenza is a cytopathic virus.
By not killing the host cell the virus does little to alarm the host defense mechanisms and slowly but surely the virus begins to leak and infect other cells until it eventually is producing enough virus to load the blood. Antibodies are proteins in the serum that bind to one kind of protein, or carbohydrate, and not others. Once the biomedics had purified HIV proteins in their hands they could use this to see if any old serum sample had antibody that would bind to it, and this becomes the first commercial way of testing the HIV status of blood. The test was reasonably good because by the time the host had produced enough HIV to be infective, the host was able to produce antibodies to the virus. If the appearance of virus had significantly preceded the appearance of antibody we would have been in a lot of trouble.