A new study in Nature Communications says scientists have found a way to prevent mother-to-child transmission of HIV with a single dose. The method has been successfully tested on primates, particularly Raveus Macaque apes.
The newborn monkeys were treated with a mixture of two antibodies against SHIV (HIV virus in monkeys) at 30 hours after exposure to the virus. As a result, they are protected from HIV.
“These promising findings could mean that babies born to HIV-infected mothers can still beat HIV with a streamlined treatment intervention.“, said Dr. Nancy Haigwood, the author of the study.
A single dose of medication can prevent mother-to-child HIV transmission
180,000 babies are infected with HIV each year
According to the World Health Organization, the HIV transmission rate from a pregnant mother to her baby can be up to 45%, if the HIV-infected mother is not treated with ARV antiretroviral drugs.
HIV can be passed from mother to child at 8 weeks of pregnancy through the placenta. The virus can also be transmitted through bloodstream, during labor or during breastfeeding.
If the mother is treated with ARV during pregnancy, labor and breastfeeding, the transmission rate can be reduced to less than 5%. However, that is not an absolute number. Each year, around 180,000 children worldwide are born with HIV. Half of them will die after 2 years if treatment is not received.
Prevention of mother-to-child HIV exposure should focus on the detection of HIV in the mother, in order to start ART early in order to reduce the viral load within the mother’s body. However, sometimes a mother may become infected with HIV during pregnancy, to be found late, during labor or breastfeeding. At this time, preventive treatment for the child must be carried out early.
Currently, preventive treatment regimens for infants at high risk of HIV infection require at least 6 weeks of continuous antiretroviral therapy. Infants must take 2 combination medicines daily, divided into several doses and start no later than 48 hours after birth.
If the child continues to breastfeed, the treatment should last for another 6 weeks. This complex regimen requires extra care and significant risk. In addition, ARV drugs that are refined into a child’s oral form also have many negative side effects, and researchers are concerned that they may affect their normal development.
So, Professor Haigwood, a pathologist and immunologist at Oregon Health & Science University, wondered if there was any way to streamline this regimen effectively.
Each year, around 180,000 children worldwide are born with HIV. Half of them will die after 2 years if treatment is not received.
Only 1 dose is needed within the first 30 hours
Together with his colleague Dr. Ann Hessell, Professor Haigwood came up with a formula of two antibodies called PGT121 and VRC07-523 that can stop HIV. The antibodies are non-toxic and can be modified to persist in the body, thereby reducing the frequency of treatment.
In a previous study, Professor Haigwood tried 4 antibodies in 10 different primate species and found that the 24-hour doses helped newborn monkeys become immune to HIV after 6 months.
With the goal of further streamlining the regimen, Professor Haigwood sought to minimize 4 doses to a single dose and extend the window time to 30 hours. Her latest test, conducted on newborn Raveus Macaque monkeys, confirmed the success of that single dose.
All monkeys given antibody combination did not develop monkey-like HIV called SHIV. This is the first time a wide dose of neutralizing antibody has been successful in preventing SHIV exposure in non-human primates.
In an attempt to expand the treatment window further, Professor Haigwood tested the combined dose of two antibodies PGT121 and VRC07-523 in four divided doses after the baby was born 48 hours. But the result was unsuccessful, 50% of the monkeys were still infected with SHIV. However, antibody treatment is not not helpful.
Professor Haigwood said monkeys after antibody use could shorten ARV prophylaxis by half. Meaning they only need to take medicine for 3 more weeks to prevent SHIV.
Professor Dr. Nancy Haigwood (front right) and her research team.
Sharing the next research direction, Professor Haigwood and colleagues said they plan to test some other antibodies to see if their combination is able to prevent HIV from attacking babies. . They also need to assess whether the PGT121 and VRC07-523 antibody mixture will actually eliminate the virus or just prevent it from multiplying.
Currently, a team of scientists in the Mother, Infant, and Adolescent Clinical Trials Network, is also working on a unique antibody that helps prevent HIV transmission from mother to child.
These studies are aiming to protect 100% of children born to HIV-infected mothers, determined to bring the infection rate to 0%. An absolute number equivalent to 180,000 children per year will be protected, contributing to the elimination of the HIV / AIDS pandemic in future generations.
Refer WHO, Medicalxpress