Hypotheses related to the decay of virion-producing cells after treatment initiation.

<p>A) Virion-producing cells are short-lived infected CD4 cells and all new cell infections are prevented due to high drug exposure. This translates into only one phase of viral decay; B) There are two types of virion-producing cells having half-lives of around 1 (short-lived) and 14 days (long-lived), respectively, and all new cell infections are prevented due to high drug exposure.[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0198090#pone.0198090.ref001" target="_blank">1</a>] This translated into two phases of viral decay C) Virion-producing cells are mostly short-lived infected CD4 cells located in two compartments, one with high (pink) and one with low (blue) drug exposure. The compartment with low drug exposure partially allows new cell infections, effectively leading to two phases of viral decay. The compartment is not associated to a specific tissue at this point, as its existence is hypothesized.