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. Eddie • 14 December 2019

   Dear all,
   Greetings,

   I had to stop my Genvoya med for one month , I wanted to know if that would have an immediate effect on my viral load which was undetectable and my cd4 was at 1220 . As soon as I came back home a restarted my Genvoya.
   Please any help would do thx .

2. Roy Trevelion • 13 November 2019

   Hi Thandeka,

   It’s great that you’re thinking of taking your meds again. Stopping HIV treatment (ART) for a year isn’t ideal. But you can talk to your doctor and say you want to start again.

   Your doctor might want to do some tests to make sure what meds will work best for you. Please let us know how you get on. You can also tell us your CD4 count and viral load results, as well as what HIV meds you’ll start to take.

3. Thandeka • 13 November 2019

   I tested positive on 2012 I took my drugs and its been a 1year 6months without taking my drugs but Im not sick I don’t lose weight is it possible to go back to take my drugs again

4. Roy Trevelion • 2 September 2019

   Hi Nomsa,

   I’m sorry to hear this is giving you stress. But it’s good that you’re taking your ARVs in time and everyday. Did the nurses mean that HIV was not detected, but now HIV is detected again?

   Please can you talk to the nurses and ask them to check your viral load again?

   Sometimes the viral load result comes back detectable. That means over 50 copies m/L. But it can be just a blip. A blip is when viral load goes above 50 copies/mL for a short time and then drops back down.

   Please let us know what ARVs you’re taking. And if you have access to your viral load results, please tell us those results too.

5. Nomsa • 2 September 2019

   Hi I’m HIV positive in 2016 nurses said the virus was not active but now when they took a blood test the results said the virus is active again, this is worrying me I never make a mistake of not taking my ARV I took my ARV in time and everyday so this is giving me a stress

6. Roy Trevelion • 12 August 2019

   Hi Gilly,

   It’s good that you started HIV treatment (ART) immediately. Starting ART is the best way to look after your health. It’s the only way to stop progress to other HIV symptoms and infections.

   Please see this guide to Introduction to ART.

7. gilly • 12 August 2019

   Hi I just got tested but had no symptoms save for flu I suppose. Ithe came out positive and I immediately started treatment. I’d like to know if this means it won’t progress to other symptoms? Really worried. (I intend on staying on treatment)

   Thank you

8. Roy Trevelion • 9 August 2019

   Hi Tebogo,

   It’s great that you started HIV treatment (ART) right away. Being on ART is the best way to protect your health. And this can also reduce the risk of HIV to your baby to close to zero.

   The aim of ART is to get your viral load to undetectable as soon as possible and before it’s time to give birth. Please see this link to HIV pregnancy and women’s health.

   If you have an undetectable viral load you cannot transmit HIV, even if you don’t use condoms. So ART can protect your partner too. Please see this link to Undetectable = Untransmittable (U=U).

9. Tebogo • 9 August 2019

   Hi i found out that i was hiv positive at 12 weeks of pregnancy i started treatment right away problem is sometimes my partner and dont use protection and he is not on treatment i am now 23 weeks will my baby be affected?

10. Roy Trevelion • 7 August 2019

    Hi Bello,

    Are you back on treatment now? What meds are you taking? And if you have access to your CD4 count and viral load, please let us know.