As you can see the virus growth curve is divided into 3 main parts. They are
- Eclipse period
- Virus burst
At attachment stage, the virus that is in the blood stream will be attached to the host cells, thus beginning to decrease in numbers, therefore having a negative gradient.
At the eclipse stage, more and more virus already penetrated the host cell and is undergoing the replication process, and thus the virus titre decreases. It reaches a 0 gradient when virus in the external medium is no longer detected.The original virus count gets subtracted from the virus released to give the virus yield.