Doctors in South Africa say a nine-year-old boy infected with HIV at birth may have been cured of the disease as he has spent most of his life without needing any treatment.

According to BBC, the little boy, whose identity is being protected, was given a burst of treatment shortly after birth, but he has since been off drugs for eight-and-a-half years without symptoms or signs of active virus.

This is unusual because HIV carriers usually need treatment every day to prevent the virus from destroying their immune system and causing AIDS.

Medical researchers say understanding how the child is protected could lead to new drugs or a vaccine for stopping HIV.

The child caught the infection from his mother around the time of birth in 2007, and tests showed he had very high levels of HIV in the blood.

However, though early antiretroviral therapy was not standard practice at the time, it was given to the child from nine weeks old as part of a clinical trial.

Gradually, levels of the virus became undetectable and treatment was eventually stopped after 40 weeks, and unlike anybody else on the study, the virus has not returned.

This is the third case where early therapy against HIV has proved ‘successful’.

“The ‘Mississippi Baby’ was put on treatment within 30 hours of birth and went 27 months without treatment before HIV re-emerged in her blood,” the report read. “There was also a case in France with a patient who has now gone more than 11 years without drugs.”

However, Avy Violari, the head of paediatric research at the Perinal HIV Research Unit in Johannesburg, said it was doubtful “that antiretroviral therapy alone can lead to remission”.

“We don’t really know what’s the reason why this child has achieved remission – we believe it’s either genetic or immune system-related,” he said.

It is worth noting that while there is no active HIV in the child’s body, the virus has been detected in the child’s immune cells. Latent HIV can hide inside the immune cells for long periods of time, so there is still a danger the child could need drug treatment in the future.

Diana Gibb, a London-based researcher, said cases like this are “exciting to see.”

“But it is important to remember it is one child,” he added. “HIV is still a massive problem around the world and we mustn’t put all our eyes on to one phenomenon like this, as opposed to looking at the bigger issues for Africa.”

There are over 36.7 million people living with HIV all over the world, and only 53% of them are receiving antiretroviral therapy.