1.13 Use of CD4 count for starting therapy (ART)

In 2023, ART is recommended at any CD4 count.

But up until 2015, the CD4 count was used to decide when to start ART.

Very few guidelines still use the CD4 count to decide when to start ART. This is because ART is both better for your health and it also prevents transmission. (See U=U: undetectable = untransmittable).

The first CD4 counts is still used to know how much HIV has damaged your immune system. It can also sometimes help estimate when you became positive.

CD4 counts and starting ART

• WHO, European, UK and US guidelines recommend people can start ART at any CD4 count. 
• Very few countries still delay ART until the CD4 count is below 500. 

Large studies prove that ART reduces the risk of HIV related infections. This includes when the CD4 count is higher than 500.

Twenty years ago, treatment guidelines recommended waiting to start ART. For example, starting at lower CD4 counts (at 500, 350 and even 200). This was because the early drugs had more side effect and because doctors didn’t understand the risks about not being on ART.

Modern ART is now much safer. In the UK at least 10 different combinations only involve taking one pill a day.

Latest drugs have fewer side effects. ART now involves fewer pills and daily doses and this makes taking treatment easier.

If you are diagnosed with a low CD4 count, ART will will still work very well.

This page links to information about each HIV drug.

Last updated: 1 January 2023.