The study, in Science Translational Medicine, found the children’s immune systems were “keeping calm”, which prevented them being wiped out.

An untreated HIV infection will kill 60% of children within two and a half years, but the equivalent infection in monkeys is not fatal.

The findings could lead to new immune-based therapies for HIV infection.

The virus eventually wipes out the immune system, leaving the body vulnerable to other infections, what is known as acquired human immunodeficiency syndrome (Aids).