Glossary

uneven distribution – a term in statistics where most results fall to the left (positive skewness) or right (negative skewness) of the middle of the range.

T-cell – a type of white blood cell (lymphocyte) that are part of the immune system and that mature in the thymus (T). CD4 cells are also called T-cells.

HIV transmission is when the virus passes from one person to another. When this is from mother to baby it is called mother-to-child transmission (MTCT), perinatal or vertical transmission. Children who become HIV-positive in this way are called vertically infected children

viral rebound – when your viral load has been undetectable (under 50 copies/mL) and then becomes detectable. Sometimes viral rebound can be a lab error, sometimes a small temporary blip, and sometimes a real rebound that shows your virus may have developed resistance to one or more of the drugs in a combination treatment. See: virological failure.

seroconversion – the immune reaction when you develop antibodies to a new infection. HIV seroconversion usually starts a couple of week after infection. Because this is when viral load is very high (often millions of copies/mL), this is when symptoms occur.

About 70% people have HIV seroconversion symptoms. Some people become very ill and need immediate ART, and other have no symptoms.