Treatment training manual

2.10 Impact of other infections (and vaccines) on viral load

Other infections can increase HIV viral load. Some vaccines can also do this. This is usually only by a small amount.

  • The immune activity caused by another virus can increase HIV viral load.
  • This is reported for some sexually transmitted infections (STIs). This can increase levels of HIV in both blood and genital fluids, but only by relatively small amounts. These STIs include herpes, gonorrhoea and syphilis. This is one reason that early studies found that STIs made HIV more infectious.
  • This is different if you are on ART with an undetectable viral load. The¬†PARTNER study¬†found that STIs did not cause HIV transmission when HIV viral load was undetectable.
  • Viral infections like the flu can increase your viral load. If your viral load becomes detectable when you have flu or a cold, please just retest when you feel better.
  • Malaria can increase your viral load while the infection is active.
  • Some vaccinations may also increase viral load. This is only for a week or two after the vaccine. This might also include COVID-19 vaccines, but again, only for a short time.
  • HIV can also increase the levels of other viruses.

Last updated: 1 August 2021.