If your viral load never became undetectable…

How quickly should viral load become undetectable?

When you first start ART, viral load drops quickly. It often becomes undetectable within a month. If not, then within three months. But sometimes this can take longer.

The time it takes depends on several things.

  • Your viral load when you started. The higher this was, the longer it will take.
  • Which HIV drugs you use. Integrase inhibitors reduce viral load faster than other meds.
  • Adherence. Drugs can only work if you take them. If you take your meds on time, viral load comes down more quickly.

Viral load should drop by at least 90% in the first month. This is sometimes referred to as 1 log (see Table 1 below). If not, your doctor will ask you about adherence and may run other tests.

If viral load is still high after three months, it is normal to change ART.

One exception

However, there is one exception that is still not well known.

Rarely, it take more than a year to become undetectable without needing to change treatment. This is if the low level viral load comes from a reservoir of sleeping cells. In this case the combination is not failing.

This can happen if someone is diagnosed very soon after infection. Also after starting treatment very early with a very high viral load.

Your clinic can’t really test for this. It has to be interpreted based on very high adherence to a combination that really should work. See the report below for more information.

Viral reservoir can explain persistent low level viraemia with good adherence on ART

What is second-line treatment?

Second-line is the name for your second combination.

If the second ART fails, the next one is called third-line.

How long should I wait?

This will depend on how low viral load has gone. Also on your individual situation.

Table 1: Log scales (a log 10 scale is a multiple of a factor of 10).

1 log = 10 1.5 log = 30 1.7 log = 50
2 log = 100 2.5 log = 300 2.7 log = 500
3 log = 1,000 3.5 log = 3,000 3.7 log = 5,000
4 log = 10,000 4.5 log = 30,000 4.7 log = 50,000

Last updated: 1 August 2021.