A small-scale HIV study suggests that the virus could be reduced to a “minor chronic infection” by using a vaccine.

Spanish researchers found that 22 of 24 people developed an immune response to HIV after being given a vaccine known as MVA-B.

Nineteen of them showed an immune response to the virus after one year.

Professor Mariano Esteban, head researcher on the project at the National Biotech Centre in Madrid, said: “If the virus enters the body and tries to develop in a cell, the immune system is ready to destroy the infected cell.”

He added: “MVA-B vaccine has proven to be as powerful as any other vaccine currently being studied, or even more.

“If this genetic cocktail passes Phase II and Phase III future clinic trials, and makes it into production, in the future HIV could be compared to herpes virus nowadays.”

The next step will be to test the vaccine in HIV-positive people to see if it has any therapeutic impact.

HIV experts welcomed the study as a “step in the right direction”.

Jason Warriner, clinical director for Terrence Higgins Trust, said: “Therapeutic vaccines are an exciting area of research. Current drug treatment is good at keeping HIV under control, but as people with HIV now routinely live well into old age, the lifetime cost of treatment can be high. An effective therapeutic vaccine could not only be less expensive, but people living with HIV might find it easier to manage.

“This trial is a step in the right direction, but until we find a vaccine that controls the virus as well as antiretroviral treatment does, we’re not there yet. This research gives us a good idea of where to concentrate efforts in the future.”