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.
I was on treatment for 5 years during this days i was stoping my treatment by my mistakes for 4 monthes and my result is detectable how can i reduce again please?
Hi Emmanuel,
If your viral load result is using Log tables, your viral load will be about 180 copies/mL. I’m sorry but I’m not sure what E03 means.
What does the doctor say about your viral load. If you’ve been on ARVs for 1 year and 7 months you should have an undetectable result by now. That’s under 50 copies/mL.
Do you have access to your previous viral load results? Please let us know. And also tell us what ARVs you’re taking.
It’s difficult for all of us to take our ARVs at exactly the same time every day. But it’s fine to aim for 9pm and give yourself a window of an hour either side of that time.
Im taking my ARV for almost 1 year and 7 months now. My CD4 300 and my Viral Load is 2.26E03 is it good or bad?
Sometimes i cant drink my ARVs on like I suppose to drink itat exactly 9pm but I drink it like minutes a head and way past 9pm and one time i missed 1. Can you help me?
Hi Ms Kay,
When someone starts treatment their viral load should become undetectable within 1-3 months of being on treatment. However in some cases it can take longer. To know if your viral load is undetectable you’ll need to have it tested. If it is undetectable, then there is no risk to your partner.
Hi I started my med (Dolutegravir) feb 2019 and my viral load was <400 and CD4 count of 350, I want to conceive, im i healthy enough to do so and will I infect my partner who is negative. When will my viral load be undetectable.
Hi Amina,
It’s good you’ve been taking ARVs for 5 months. In the UK and US treatment guidelines recommend that your viral load should be undetectable within three months of starting ARVs.
If you’re undetectable the risk to your partner is zero. That’s because Undetectable = Untransmittable, even if you don’t use condoms. Pleae see U=U here for more info.
I have been on ARVs for 5 months and I had unprotected sex with my negative partner, will he be infected?
Hi Jojo,
Please talk to a doctor about the rash and the itching.
With regards to your viral load, it’s near enough undetectable. Has it even been below 50?
I have been taking ARVs for 18 yrs . My CD 4 count is 849 en my Viral load is 66 . Is this means the medication is working fine .. ?.. The problem is my face , is full of rush en is itching . What can I use or eat to remove this rush en itchiness ?
Hi Lulama,
It really isn’t possible for me nor anyone else to predict if your child is going to be positive or not. However, your viral load is very low, so the risk is minimal. Please see here for more info: http://i-base.info/guides/pregnancy