Question

During years 1-6 of infection, HIV evolution is extremely fast, but it slows down during year 7. What would be the underlying cause for the HIV virus evolution to slow?

1) Replication of the HIV virus decreased
2) CD4 T cell count decrease
3) Increase in the change of novel epitopes
4) Viral load decrease

Answer 1

The slowdown in HIV evolution around year 7 is primarily due to a decrease in CD4 T cell counts, which reduces the number of cells available for the virus to infect and replicate within, thus limiting opportunities for mutation and evolution.

Step-by-step explanation:

During years 1-6 of infection, HIV evolution is very fast due to rapid viral replication and a high immune system response. However, around year 7, the evolution of the virus tends to slow down. One of the main reasons for this slowdown is the CD4 T cell count decrease. The HIV virus targets these cells, and as the number of CD4 T cells drops, there are fewer cells for the virus to infect and replicate within. This reduces the potential for the virus to mutate and evolve. Additionally, antiretroviral therapy can help to maintain lower viral loads, further limiting the opportunities for HIV to evolve within the host.