"What seems to be clear to me is that after the primary infection most of the cells die indirectly, but at the later stage, when the viral load is very high, the virus kills a lot of cells directly"

This quote by Luc Montagnier suggests that throughout the initial stages of a viral infection, the majority of the cells die indirectly due to the infection. This could be due to the body's immune reaction to the virus, which can trigger inflammation and damage to the cells. However, as the viral load increases, the infection begins to directly kill a great deal of cells. This might be due to the infection replicating and taking control of the cells, or due to the virus releasing toxins that harm the cells. This could result in more extreme signs of the infection, as the infection has the ability to spread out quicker and trigger more damage. Montagnier's quote highlights the significance of comprehending the different phases of a viral infection, and how the virus can cause different kinds of damage to the cells.