CD4 & Viral Load

When first diagnosed you will hear a great deal about CD4 and Viral Load.

• CD4 measures how well your immune system is functioning.    
• Viral Load measures how much virus is in your body.

CD4

• Measures the strength of the immune system by counting how many CD4 cells are present in a cubic ml of blood    
• A healthy immune system is usually 350 and above    
• You will be advised to start treatment straight away, to help your immune system recover    
• CD4 will be reflective of general health    
• CD4 percentage is the percentage of white blood cells (lymphocytes) that are CD4 cells.    
• 30% – 66% of white blood count is normal    
• CD4 ceases to be important once you have started medication and become undetectable.

Viral Load  

• Measures the amount of virus present in a cubic ml of blood.    
• Also in semen—including precum—vaginal fluid and breast milk    
• The lower the viral load the less strain on the immune system, and the less transmittable the virus  
• The goal of medication is to reduce viral load to less than 50 copies in a ml of blood    
• Under 50 copies in a cubic ml of blood = UNDETECTABLE

What does UNDETECTABLE mean?    

• A healthy immune system    
• Normal life expectancy    
• No transmission risk    
• Reduced risk of ill health regarding HIV    
• Reduced risk of mother to child transmission in pregnancy and breastfeeding    
• You can be employed in any job    
• Protection under the law

For more information use the NAM website:

If you have any further questions, please talk to your consultant, doctor, nurse, health advisor or the peer support workers.

You can contact the peers support workers directly on 020 3317 5177.