Question
How quickly does viral load drop on treatment?
5 July 2020. Related: All topics, CD4 and viral load, Starting treatment.
I’ve been trying to understand on average, the daily rate of decrease in viral load following initial treatment.
I’m guessing that this changes over time and varies from case to case according to the chosen treatment, CD4 count and viral load level and possibly other factors.
However, supposing that the viral load is around 100,000, the CD4 count is around 400 and the treatment used is Atripla, could anyone please let me know the expected % decrease of viral load level per day at least within the 1st month of treatment?
Thank you for the help.
Answer
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.
Some researchers also talk about a third phase decline which occurs even more slowly and gradually once your viral load is undetectable.
This relates to a reduction in the levels of infected CD4 cells that are latent (or resting). This pool of cells only slowly decreases over time.
This link is to an early study describing the two-phase viral load reductions.
This answer was updated in July 2020 from a question first posted on 15 September 2012.
Hi, am Danzy!
Am on ART meds for two months plus now. Is it possible I would have achieved suppressed viral load? Also, when I didn’t ejaculate on the virgina, is it possible my partner will be infected?
I don’t really have easy access to proper test kit to determine the rate of my viral load but I am on strict adherence to my meds as prescribed.
Hi Jasmine, starting TLD is how your viral load will drop. It is likely you will see a massive drop in the first few weeks and from then it will slowly reduce and become stable. Within the first month, it is possible for your viral load to become undetectable, though guidelines do suggest that this can be up to 3 month.
Hi my name is Jasmine, I just started taking my TLD after checking my viral load and it’s about 25000.
Is there possibility to drop down
Hi Mercy, what was the value of your viral load? Some tests can be more specific and pick up lower levels of viral load. Any value under 200 is considered undetectable.
I started treatment on 2012 and my viral load was undetected so this year August my viral load is detectable iam using the combination of 300 tenovir.lamivudine and 50 DTG
Hi Mavia,
There’s still time for your viral load to become undetectable, by the time you give birth it may be undetectable.
A viral load of 400 is low, so the risks to your baby will be minimal.
If it’s still detectable then having a c-section might be recommended, this is something that you’ll need to talk to your doctor about.
Am 8 months pregnant my viral load is 400 can I manage to give birth to hiv negative baby if am taking my medication accordingly I just want my undetectable viral load back
Hi Jojo,
Are you now back on your meds? If you are, you should be OK. If you can it’s best to have a viral load test, just to be sure.
Hi I’m Jojo I’m on biktarvy My viral load has been undetectable every since I found out I was positive back in 2015 of September . I’ve recently missed a few weeks of meds due to not being able to get access to my meds. Should I be concern about my viral load.
Thanks Jozy, please check the active ingredients in your meds. It is common to change the brand of medicine and this might be what is happening. Changing the actual combination many times is unusual. Yoru docotr or clinic should confirm this.