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.
My VL was 989 in January 2018 (1st HIV+ Diagnosis) and I started ART right away, and my husband was on 49 000 with TB, he started TB treatment right away and followed up with ART begining of February 2018.We have been on ART religiously and been practicing safe sex from then. We eat healthy and don’t drink, is it safe to say our VL has been suppressed? We want to start a family as soon as possible. What is the estimated VL at this stage?
Hi Craig,
Unless you have issues with your meds, then their’s no reason why your VL will rise once it becomes undetectable on medication. Though an elite controller, being on meds is the right thing to do.
At my first V/L test my cd4 was 570 and my V/L was 63. I was told I am a long term non progressor, I still decided to take medication to make sure it was controlled, how likely is my V/L to spike and rise ?
Hi Leslie, Have you been taking medication for long? As it says on this question above, many people get to undetectable within about three months. But, some people can take longer. You can talk to your doctor about what meds you’re taking and how long you’ve been taking them. You can ask to find out if they are working well. But adherence to medication is the only way to get undetectable.
How Can I Get My Viral Load From 400 To Undetectable Besides Adherence Of Medication?
Hi Leslie,
The research that we have that looks at transmission refers to viral loads that are undetectable, so less than 50.As your viral load is 400 its very possible that you could transmit HIV. Though the risk would be minimal. Its up to you and your partner if you want to take the risk.
As your viral load fluctuates have you had resistance tests done?
I am currently on atrozia my viral load is 400.my viral load was undetectable 1year 6 months ago.its been up and down since then but never more than 400.Can A viral load of 400 be considered as low and is it possible that I can transmit to my partner with a viral load of 400?
Hi Edmundo, Guidelines in the UK recommend starting treatment at any CD4 count. You can see more info on this question here.
I was recently detected positive on January 2018 i have a CD4=559 and a VL=64,937.00 can I start ARV. I am really confused about this
Hi Magesh, Have you tried contacting the Treatment Action Campaign? They might be able to offer information and support on this issue.