[salvage therapy] A treatment strategy for managing HIV in people who have developed resistance to existing therapies.

[Severe Acute Respiratory Syndrome] A new respiratory illness which was first reported in Asian countries during late 2002 and early 2003. The symptoms include high fever, cough, malaise and difficulty in breathing. Several laboratory tests for the SARS virus are now available.

The measurable holding point or balance between the virus and the body's immune system reported as the viral load measurement. The viral set point is established within a few weeks to months after infection and is thought to remain steady for an indefinite period of time. Set points are thought to determine how long it will take for disease progression to occur. [NIH]

Any undesired actions or effects of a drug or treatment. Negative or adverse effects may include headache, nausea, hair loss, skin irritation, or other physical problems. Experimental drugs must be evaluated for both immediate and long-term side effects.

Before a drug has been approved, manufacturers often provide the drug free of charge to people who cannot participate in a clinical trial and who meet certain criteria under a Special Access Scheme (SAS).

A substance which is structurally similar to human sex hormones which is used for therapeutic purposes due to its anti-inflammatory effects.

[Sexually Transmissible (or Transmitted) Infection] Infections spread by the transfer of organisms from person to person during sexual contact. Also called venereal disease (VD) (an older public health term) or sexually transmitted diseases (STDs).

[HIV strain] Any subgroup of the HIV species. Because HIV mutates very easily, there are many different strains (and may be multiple strains within a single person).

[HIV subtype or clade] A genetically distinct subtype of HIV within a defined HIV group. Group M has nine known subtypes -- A, B, C, D, F, G, H, J and K.