In people, one study administering two bnAbs also saw suppression of HIV replication and nearly undetectable viral loads. One early-phase clinical trial in 2021 showed that one bnAb could potentially offer protection against HIV infection.

All the monkey and human studies mentioned above required re-administering the broadly neutralizing antibodies every three weeks or so to maintain effective concentrations. This runs into the same problem antiretroviral therapies face in terms of requiring the individual to retake the drug frequently for life. But researchers have found a potential solution.

Using a small virus that doesn’t cause disease, called an adeno-associated virus, to deliver broadly neutralizing antibodies into the body can stimulate muscle cells to continually produce these antibodies. Because muscle cells have a prolonged life span and can last on average 10 to 16 years, they can be turned into factories that produce the antibodies essentially for life.

One study my colleagues and I conducted using adeno-associated virus found that one monkey was able to produce these antibodies for over six years after a single injection.

Another monkey that researchers dubbed the “The Miami Monkey” is considered functionally cured, meaning its viral loads have been at undetectable levels for prolonged periods even without continuous antiviral drug therapy. Two other monkeys have also been cured of their AIDS virus infections with this approach.

Adeno-associated virus vectors for HIV antibody therapies still face one more hurdle: anti-drug antibodies, or antibodies the body produces in response to the antibodies in the treatment. Anti-drug antibodies can result when the body registers an antibody treatment as foreign and mounts an immune response against it, negating the treatment. They have also have caused problems for antibody treatments in cancer and autoimmune disorders. That may especially be the case for broadly neutralizing antibodies, which have unusual structures that deviate from what the body normally expects an antibody to look like.

Researchers are working hard to develop simple and accessible approaches to help patients build tolerance to broadly neutralizing antibodies. Some of these approaches include delivering treatments to other areas that have greater immune tolerance than the muscle, such as to the liver and through the mouth.

Stay tuned.

This article is republished from The Conversation, an independent nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Ronald C. Desrosiers, University of Miami. The Conversation has a variety of fascinating free newsletters.

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Ronald C. Desrosiers receives funding from the National Instituyes of Health. He receives no corporate/commercial/company support.