Researchers are one step closer to a possible “functional cure” for HIV. At a conference in Boston, scientists from the University of California, San Francisco presented promising results from a new immune therapy.

In three participants, the virus was successfully suppressed for a prolonged period after a single treatment using genetically modified immune cells, without the need for regular medication. In two patients, HIV even remained undetectable for several months to nearly two years. The therapy works by modifying immune cells so they can both destroy HIV-infected cells and protect themselves against infection.

Although the research is still at an early stage, scientists see this as an important step towards a long-lasting, potentially one-off treatment for HIV. More than 40 million people worldwide are currently living with the virus.