Key Takeaways:
- A single antibody dose administered within 30 hours of SHIV exposure prevented viral reservoir formation in newborn monkeys, offering a potential alternative to weeks of antiretroviral therapy (ART) for HIV-positive mothers’ infants.
- Treatment effectiveness drops if delayed beyond 48 hours, highlighting the critical window for intervention post-birth.
- Antibodies are less toxic than traditional ART and can be engineered for long-lasting effects, reducing treatment frequency and side effects.
- With ART, mother-to-child HIV transmission rates fall below 1% in developed countries. However, 82% of HIV-positive pregnant women globally now access treatment, cutting new child infections by 41% since 2010.
- If human trials replicate results, this protocol could simplify neonatal HIV prevention, especially in resource-limited settings.
Scientists at Oregon Health & Science University School of Medicine developed a protocol capable of preventing the formation of a viral reservoir with a single dose in monkeys that had been exposed to the AIDS virus. Ultimately, this discovery may make it easier to treat babies born to HIV-positive mothers.
Newborn
In 2017, 180,000 children under the age of 15 were infected with HIV worldwide, most of them by their mothers. An HIV-positive woman can transmit the virus to her child during pregnancy, childbirth, or breastfeeding. To avoid this risk and to protect their own health, sick women mainly take antiretroviral therapy drugs during pregnancy. But these drugs can have many negative side effects, and researchers are concerned about the long-term consequences for babies. Now, U.S. scientists have succeeded in establishing a protocol that can prevent the formation of the viral reservoir with a single dose of antibodies in baby monkeys. However, for this to work, the treatment must be given very quickly. Their work was presented in the journal Nature Communications.
Since the antibodies are not toxic and can be modified to last a long time in the body, this reduces the frequency of treatment. A team of researchers came up with the idea of exploring its potential to replace or complement the antiretroviral therapy currently used in newborns of HIV-positive mothers, as well as in HIV-positive adults.
They worked with young monkeys infected orally with SHIV-1, a similar form of HIV for monkeys. By giving them a combination of two antibodies 30 hours after exposure to the virus, they found that the single dose was enough to block its entry into immune cells. Six months later, the monkeys were still protected.
Promising results
But if scientists waited 48 hours before giving four small doses of the same antibody, half of all baby monkeys would develop SHIV. Finally, monkeys who received the current standard treatment did not get sick when treatment began 48 hours after exposure to the virus.
Therefore, this study suggests that instead of the usual cocktail to which human babies born to HIV-positive mothers are exposed (various drugs for about six weeks before retesting), a much shorter antiretroviral treatment could prevent the transmission of AIDS to the newborns. This, however, can work only if the treatment is started quickly after birth.
“These promising findings could mean babies born to HIV-positive mothers can still beat HIV with less treatment,” said Nancy Haigwood, Ph.D., a professor of pathobiology and immunology at the Oregon Health & Science University School of Medicine. More research is needed to test the effectiveness of treatment in monkeys soon after birth.
Less than 1% transmission rate when mother and child are treated
In the absence of treatment, the transmission rate from an HIV-positive mother to her child is approximately 20%. These rates vary according to the mother’s clinical and immunological status. However, in developed countries, sick mothers often receive clinical treatment. Treatment of the mother during pregnancy and then of the child after birth can reduce the transmission rate to less than 1%.
According to a UNAIDS report released this summer, some 82 % of HIV-positive pregnant women worldwide now have access to the drugs, an increase of more than 90 % since 2010, which has led to a 41 % reduction in new infections among children.
FAQs:
How does this differ from current HIV prevention for newborns?
Current protocols require 6+ weeks of ART drugs. This antibody approach could replace or shorten treatment to a single dose, minimizing side effects and logistical barriers.
Why is timing crucial for the antibody dose?
HIV establishes viral reservoirs rapidly. Administering antibodies within 30 hours blocks viral entry into immune cells, preventing lifelong infection.
What was the success rate in monkeys?
100% protection when given within 30 hours; delayed dosing (48 hours) led to infection in 50% of cases.
When might this be available for humans?
Further trials are needed, but the non-toxic, long-acting antibodies could advance to human studies within 3–5 years.
References
Shapiro, M.B., Cheever, T., Malherbe, D.C. et al. Single-dose bNAb cocktail or abbreviated ART post-exposure regimens achieve tight SHIV control without adaptive immunity. Nat Commun 11, 70 (2020). https://doi.org/10.1038/s41467-019-13972-y
