Question

All HIV combinations (ART) starts working from the first dose.

Viral load is usually reduced by 90% (also referred to as 1 log) within the first few days. It then continues to fall but not as quickly (see below) until it becomes undetectable.

A log is a number mulitplied to the power of 10. So with a viral load of 100,000 copies/mL, a 1-log reduction would bring your viral load down to 10,000 copies/mL and a 3-log reduction would reduce it to 100 copies/mL. (See this factsheet).

You are right that individual factors will lead to difference rates of viral load reductions. These include:

• How high your viral load was when you start ART.
• The medicines in the combination (integrase inhibitors casuing the fastest drops).
• The drug levels of this meds (related to adherence and how they absorb and processes drugs).
• Good adherence – not missing doses.

UK and US guidelines recommend that your viral load should be undetectable within three months. However, many people achieve this within the first month, especailly if they are using an integrase inhibitor.

Some people take longer, especially if their viral load is very high when they start treatment.

Lots of studies have reported detailed early responses ART, including for efavirenz-based combinations like Atripla.

This decline is often referred to as having three main phases.

The first phase is very rapid – referred to in some studies as being the first few days and in others as within the first two weeks. This is where the actively infected CD4 cells are targeted. CD4 cells infected with HIV only live for a few days and when you start treatment this virus and these cells are quickly reduced.

This results in a viral load drop of perhaps 99% (2 logs) within two weeks.

The second phase, out to the first month is slower, as it is working on cells that live longer. This can easily reduce viral by another 90% (another 1 log reduction). In people with very high viral loads when they start treatment, this second phase may continue for longer until viral load becomes undetectable.

301 comments

1. Rebecca McDowall • 3 July 2012

   Hi Mussie,

   It’s great that you’ve started treatment. Can I ask how you are feeling?

   As the answer above suggests you should expect your viral load to drop quickly. It may take between 3-6 months to get this to undetectable. You should also see your CD4 count increase, although this is slower than the change in viral load. This graph shows average CD4 increases after starting treatment.

2. Mussie • 3 July 2012

   My cd 4 count was 91 and the viral load 445000 when i started treatment 4 days ago,what should be my expectations

3. Rebecca McDowall • 11 June 2012

   Hi Chunky,

   Are these figures correct? Both the viral load and CD4 count you have given here are much higher than ususal, I wonder if there has been a typing error?

4. chunky • 9 June 2012

   Hi, my husband’s cd4 count was 9000 and viral load 750000 when tested about 2 weeks ago. He has been taking nevirapine,lamivudine/stavudine. Should his numbers be looking good and health improving by now?

5. Simon Collins • 21 December 2011

   Hi

   It is important that you were diagnosed early in your pregnancy. This is because you have been able to start treatment in time to reduce your viral load to undetectable levels before giving birth. HIV viral load at delivery is the highest risk to your baby. Reducing this to much lower levels, hopefully to undetectable, will make it much more likely that your baby will not be infected.

   See the i-Base guide to HIV and pregnancy for more information.

6. Tlaleng • 21 December 2011

   Hi

   I’m 3 months pregnant
   My CD4 was 84 when I started treatment on 15 November 2011 and I’m taking Tenoforvir 300g, Lamivudine 150g and Nevirapine 200g

   Does this mean any chance of survival of me and my baby?
   I’m worried because I haven’t fall sick

7. Simon Collins • 11 October 2011

   Hey, this sounds like you are having a great response to treatment.

   I can’t comment on all your results, but if your CD4 count has increased from 2 to 141, your immune system is now much stronger. This means you are already at a much lower risk from HIV-related complications.

   Good luck.

8. Thabo • 10 October 2011

   Hi,

   I had a CD4 count of -2 when I got sick early in March 2011, the recent result came in at CD4 count 141 and Viral Load 66- what does this mean?

9. Simon Collins • 5 October 2011

   This varies a lot. For most people a gradual increase is good. By perhaps 100 or more in the first year and if you are lucky another 100 in the second year. Some people have much higher and faster responses but steady is fine.

   your CD4 count is already pretty good, getting above 300 dramatically reduces your risks of most HIV-related health problems.

10. REF • 3 October 2011

    my CD4 count is 226 and i have started treatment will it go up? and how long does it take.