Even though HIV cannot be cured, a human immunodeficiency virus infection can now be treated very effectively.

Antiretroviral drugs, for instance, have been successfully used to treat HIV infection since the mid-1990s. These suppress the virus and prevent it from replicating. This means it is no longer transmissible and can be held in check. Most HIV patients receive a combination of different antiretroviral drugs, depending on the respective stages of the HIV cycle.

This therapeutic approach usually entails patients taking one or two tablets every day. The regimen is complemented by checkups, which should be carried out every three months. During those checkups, doctors measure a patient's viral load, testing how much HIV RNA is in their blood. The lower the viral load, the better.

HIV treatment therapy has continued to improve, said Hendrik Streeck, an HIV/AIDS research specialist and the director of the Institute of Virology at Bonn University Hospital.

The latest major breakthrough, according to Streeck, was in integrase inhibitors. The integrase enzyme plays an important role in the replication of HIV and is responsible for integrating the viral DNA genome into the host cell, where it can multiply. Integrase inhibitors keep them from being able to do so.

"This drug is enormously effective," Streeck told DW. "Integrase inhibitors have saved the lives of many patients who may already have had a very resistant viral infection and for whom there were hardly any drugs available. They are now part of every therapy."

More effective drugs in the pipeline

One branch of HIV research has focused on developing drugs that will cause little to no side effects in patients, even though side effects are already rare. Research into how drugs can be administered more simply and efficiently is also being carried out.

This includes, for example, exploring methods that will release drugs into the body at defined intervals. Some researchers are looking into an implant to facilitate this process. A wide variety of treatments are being developed around the world, some of which are already being used in practice. Others are still in the research phase.

"More and more effective treatments are available, but the big question remains how to achieve long-term efficacy," said Streeck. "In the near future, patients will receive an annual injection instead of swallowing a tablet every day."

This is welcome news for people with HIV, especially as more effective treatments mean patients are not constantly reminded of their health condition.

Working on a vaccine

Even after four decades of research, virologists have been unable to develop an HIV vaccine. That said, AIDS research has, nevertheless, made significant contributions to the development of other vaccines, such as those to combat COVID-19.

"We wouldn't have had the coronavirus vaccine so quickly if we hadn't done all the HIV research beforehand. Many of the ideas used were developed in vaccine research," said Streeck.

Many people want an HIV vaccine to be developed as quickly as possible. But initial success stories are often followed by setbacks. This even applies to drugs or vaccines in the advanced development stage. The latest HIV vaccine trials, for example, were stopped because they proved ineffective.

"Unfortunately, we still haven't figured out why we can't manage to build up sterilizing immunity," said Streeck.

There have been eight advanced-stage efficacy studies, he told DW. "They all failed, except for one. We had one vaccine — called the Thai trial because the study was carried out in Thailand — showing 31% efficacy. But we have been unable to replicate that effectiveness in any other trials."

Developing an effective HIV vaccine is difficult because the virus is constantly changing, giving rise to countless new HIV variants. And while some antibodies are quite capable at fighting one HIV variant, they are completely ineffective against others.

Containing the pandemic

Global AIDS research is also focusing on the CRISPR-Cas9 gene-editing tool, often described as "gene scissors." This tool could be used to remove genetic HIV material from human DNA, or allow for a reprogramming of immune cells. Ideally, these reprogrammed immune cells could then kill infected cells.

Intense research is also being conducted on antibodies that can recognize and block the replication of different HIV variants.

Until these treatments are readily available, everyone should be properly educated about HIV and have access to tests, prophylactic measures and medical treatments, said Streeck.

He is optimistic about the fight against HIV/AIDS. "HIV patients who receive proper treatment can no longer pass on the virus, and we have prophylactic measures that can protect against HIV infection," he said. "We are already containing the pandemic."

This article was originally written in German and published December 1, 2023. It was updated July 18, 2024.