The Human Immunodeficiency Virus (HIV) causes HIV infection, and with time it advances to Acquired Immunodeficiency Syndrome (AIDS), where it causes progressive failure of the immune system and allows life-threatening opportunistic infections and cancers to thrive.
A new study on non-human primates has discovered that a single dose of antibody-based treatment can prevent HIV transmission from mother to baby. Published in Nature Communications, this study is the first to find that a single dose of broadly neutralizing antibodies given after viral exposure can prevent SHIV infection in nonhuman primate newborns.
This new study used rhesus macaque infants to investigate the transmission of the monkey form of HIV, called SHIV, from mother to baby. They used a combination of two antibodies called PGT121 and VRC07-523.
When the rhesus macaques received the single-dose combination of two antibodies 30 hours after being exposed to the virus, they did not develop SHIV. When the treatment was delayed for 48 hours, half of the baby macaques developed SHIV when they were given four smaller doses of the same antibody combination. In contrast, when using current standard HIV treatment (ARVs) after 48 hours, the baby macaques remained SHIV-free with a three-week regimen of therapy.
HIV-positive women usually take antiretroviral therapy drugs during pregnancy for their health and the health of their growing child. But mother-to-baby transmission sometimes can still occur. The scientists discovered that their recent findings could mean less treatment can be used and still conquer HIV in babies born to HIV-positive mothers when using antibodies, and the single dose is given priority.
When babies are born from HIV-positive mothers, they are all essentially given antiretroviral therapy daily for about six weeks before being re-tested to prevent infection further. It’s not certain that they will be HIV free, so if the test comes back positive, they will most likely need to take HIV drugs for the rest of their lives. Many negative side effects come with using antiretroviral therapy, and scientists also worry about its long-term effect on development.
On the contrary, antibodies are not toxic and can be modified to last a long time in the body, reducing treatment frequency. The scientists are now looking at the potential to increase the effectiveness of the antibodies and whether it can replace or supplement antiretroviral therapy for infants with HIV-positive mothers, as well as for HIV-positive adults.
This team of scientists plans to take the next steps, which include identifying the most effective combination of treatment and determine how the antibodies work if they eliminate HIV or only prevent it from replicating.