Final answer:
Different variants of HIV can infect various cell types based on compatible receptors on the host cell surface, primarily through CD4 and co-receptors. The rapid mutation of HIV hinders antibody effectiveness and complicates vaccine development, requiring treatments to target viral replication.
Step-by-step explanation:
The different variants of HIV determine the types of cells they can infect based on the presence of specific binding sites on the host cell's surface that are compatible with the glycoproteins on the virus's surface. Receptors such as CD4 and co-receptors like CCR5 or CXCR4 are required for the virus to gain entry into the target cells, which primarily include helper T cells (CD4+ T cells), some monocytes, and central nervous system cells.
The virus exploits these cells' receptors to attach, enter, and replicate within them, utilizing the host cell's genetic machinery. The rapid mutation of these recognition sites on HIV complicates the immune system's ability to produce effective antibodies, and this hinders the development of a vaccine that can target these evolving recognition sites. Targeting the viral DNA replication process through antiretroviral drugs is one method of treatment that prolongs the lives of HIV-positive individuals.