A woman from Argentina is believed to be the second known person whose body naturally eliminated the human immunodeficiency virus (HIV) without treatment.

The 30-year-old woman showed no signs of HIV — which can develop into AIDS if untreated — eight years after her initial diagnosis, despite not receiving stem cell or other regular treatments, apparently making her a rare case of what is described as a "sterilizing cure," CNN Health reported.

The new study was published in the Annals of Internal Medicine.

The first patient who was found to have been naturally cured of HIV was a 67-year-old woman named Loreen Willenberg, according to CNN Health. 

"Examples of such a cure that develops naturally suggest that current efforts to find a cure for HIV infection are not elusive, and that the prospects of getting to an 'AIDS-free generation' may ultimately be successful," said Xu Yu, who co-authored the study, to CNN. 

CNN reported that Yu, of the Ragon Institute of Massachusetts General Hospital, MIT and Harvard, and her colleagues in Argentina analyzed blood samples of the HIV patient between 2017 and 2020. The woman also gave birth in March of 2020, which also allowed the researchers to collect tissues from the placenta.

The woman did not take anti-retroviral treatment until 2019, when she became pregnant; however, after she delivered a healthy baby who did not test positive for HIV, the woman ceased the HIV therapies. 

It is currently not clear how the woman's body was able to eliminate HIV, though Yu wrote to CNN that it was likely a "combination of different immune mechanisms." 

"Expanding the numbers of individuals with possible sterilizing cure status would facilitate our discovery of the immune factors that lead to this sterilizing cure in broader population of HIV infected individuals," she added.