According to a study published in the New England Journal of Medicine, researchers have found that a two- or three-drug combination can reduce the risk of mother-to-child HIV transmission by around 50%.
At present, zidovudine (AZT) is routinely given shortly after birth to non-breastfed babies born to HIV-positive mothers who didn’t receive antiretrovial therapy (ART) during pregnancy in order to prevent HIV transmission.
Although AZT is effective on it’s own, infants can still contract HIV during labor and delivery. Now researchers from the University of California, Los Angeles, have found that a two- or three-drug combination given to newborns within 48 hours of birth can significantly reduce the risk of such intrapartum HIV acquisition by about half, compared to AZT alone.
Lead researcher of the study, Dr. Karin Nielsen-Saines, a professor of pediatric infectious diseases at the David Geffen School of Medicine at UCLA, and a member of the UCLA AIDS Institute explained:
“Our research demonstrates that even in very high-risk situations where mothers are only identified as being HIV-positive when they give birth or shortly after birth, there is still an effective strategy that can be undertaken to prevent transmission of HIV to the baby.
While giving AZT alone to the infant can reduce intrapartum transmission to some degree, our data demonstrates that with the use of two- or three-drug regimens to the baby, you can cut transmission to half of what can be achieved with AZT alone.”
In many countries, HIV-positive women are advised not to breastfeed in order to reduce the risk of HIV transmission. Non-breastfed babies born to HIV-infected mothers who have not received ART have a 25% risk of contracting the virus during pregnancy or birth. However this risk increases to around 40% when babies are breastfed.
The researchers examined 1,684 non-breastfed babies born to HIV-positive mothers in the United States, Argentina, Brazil, and South Africa. Within 48 hours of birth 566 babies were assigned to receive AZT alone, 562 babies were assigned to receive AZT in addition to nevirapine, and 556 were assigned to receive AZT, nelfinavir and lamivudine.
According to the researchers 97 babies contracted HIV during pregnancy and 43 contracted the virus during birth.
Of the 43 infants who contracted the virus during birth, 4.8% in the AZT-alone group were infected with the virus at 3 months of age vs. 2.2% in the AZT/ nevirapine group, and 2.4% in the AZT/nelfinavir/amivudine group.
These findings show that giving two or three drugs to newborns was significantly more effective at reducing HIV transmission than AZT alone. Furthermore, the team found that AZT in addition to nevirapine was less toxic than AZT, nelfinavir and amivudine.
According to Nielsen-Saines, infants born to HIV-infected women who receive ART during pregnancy have a less than 1% chance of contracted the virus.
The researchers note:
“Our results support combination ART regimens instead of zidovudine alone for prophylaxis in the infants of mothers who have not received antenatal ART. Ease of use, reduced toxicity, availability, and low cost suggest that zidovudine plus nevirapine is an attractive option for prophylaxis in infants at high risk for perinatal HIV-1 infection.”
Written By Grace Rattue
“Three Postpartum Antiretroviral Regimens to Prevent Intrapartum HIV Infection
Karin Nielsen-Saines, M.D., D. Heather Watts, M.D., Valdilea G. Veloso, M.D., Yvonne J. Bryson, M.D., Esau C. Joao, M.D., Jose Henrique Pilotto, M.D., Glenda Gray, M.D., Gerhard Theron, M.D., Breno Santos, M.D., Rosana Fonseca, M.D., Regis Kreitchmann, M.D., Jorge Pinto, M.D., Marisa M. Mussi-Pinhata, M.D., Mariana Ceriotto, M.D., Daisy Machado, M.D., James Bethel, Ph.D., Marisa G. Morgado, Ph.D., Ruth Dickover, Ph.D., Margaret Camarca, M.P.H., Mark Mirochnick, M.D., George Siberry, M.D., Beatriz Grinsztejn, M.D., Ronaldo I. Moreira, M.Sc., Francisco I. Bastos, Ph.D., Jiahong Xu, M.P.H., Jack Moye, M.D., and Lynne M. Mofenson, M.D.
NEJM , June 2012,