HIV (Human Immunodeficiency Virus) is a virus that
infects particular cells of the immune system, called CD4
If left untreated, HIV gradually weakens the immune system of an
infected person making them more susceptible to other infections
which may put their life at risk.
HIV can be transmitted through unprotected sexual intercourse
(anal or vaginal), sharing of contaminated needles, transfusion of
contaminated blood, and between a mother and baby during pregnancy,
childbirth, and breastfeeding.
AIDS (acquired immune deficiency syndrome) is a term that
describes the point at which an infected person’s immune system can
no longer function properly because of the damage caused by HIV,
and they get one or more specific, often severe, illnesses.
It can take up to 10-15 years for an untreated person to advance
to AIDS. Antiretroviral drugs significantly slow down the
progression of HIV infection so lessen the chance of developing
AIDS-defining illnesses and the result is that HIV-infected people
can now expect to live much longer. However, many HIV-infected
people (approximately one third in the UK) are not aware of their
infection and so are unable to fully benefit from antiretroviral
In many parts of the world, especially sub-Saharan Africa,
antiretroviral drugs are not affordable but have started to be made
freely available in 2004 by donors such as the Global Fund, for all
those who are eligible to start treatment. By the end of 2008
approximately 33 million people were living with HIV worldwide,
while 2 million had died from HIV/AIDS.
The HIV Group at the MRC Clinical Trials Unit is involved in
co-ordinating and running a number of major international clinical
trials of antiretroviral and immune therapy, and different
treatment strategies. We also co-ordinate a number of national and
international observational studies that help us to understand the
progression of HIV and the longer-term effects of treatment.
The main objectives of the MRC Clinical Trials Unit HIV Group
- Identify and recommend optimum strategies for treating and
monitoring people with HIV
- Investigate effective ways of preventing HIV transmission
- Monitor clinical outcome and HIV drug resistance
For more information on HIV, visit the useful links