There were two notable announcements in the fight against HIV this week at AIDS 2020, the 23rd International AIDS Conference -- a possible case of long-term remission from the virus, and research that found an injection can prevent HIV, CNN reports.

Scientists presenting at the conference said a Brazilian man might be the first person to experience long-term HIV remission after being treated with only an antiviral drug regimen -- not stem cell transplantation. He had been diagnosed with HIV, the human immunodeficiency virus that causes AIDS, eight years ago and now shows no sign of the virus, scientists said. However, the finding involved only one patient and the research has not yet been published.

Since the AIDS epidemic began in the 1980s, just two people have been cleared of the HIV virus long-term with stem cell transplants. The stem cell treatment for HIV is complicated, risky, and can leave people vulnerable to infection, studies have found. And it may not work because the body can reject the transplant.

In the case discussed by researchers from the Federal University of Sao Paulo, the man -- who was 34 years old at the start of the study -- was among 30 participants from a clinical trial investigating treatment approaches with the hope of possibly finding a cure for HIV.

The man, who enrolled in the trial in 2016, was 1 of 5 given a "highly intensified" antiretroviral therapy with the drugs dolutegravir and maraviroc and 500mg twice daily of nicotinamide, a form of vitamin B3, for 48 weeks.

In the trial, the researchers monitored and measured viral DNA that could be detected in each participant. The researchers noted that the man interrupted his treatment in March 2019 and he was tested for viral DNA every three weeks after for up to 57 weeks. By 57 weeks, the researchers found his total HIV DNA "was undetectable" and his HIV antibody test remained negative, according to the study.