Researchers at UCSF have discovered that azithromycin, a non-teratogenic antibiotic, can protect specific fetal brain cells from Zika infection. It was determined that the AXL protein serves as a receptor for the Zika tropogen, and that fetal brain cells with an abundance of AXL expression are preferentially targeted by the virus. This finding is remarkable because it contrasts with previous studies of Zika infection in mice. The UCSF study notes that cells at high risk of infection are neural stem cells, progenitor cells, astrocytes, and microglia.
Researchers then tested 2,177 FDA-approved drugs to determine if any could prevent infection in cultured brain cells. They found that azithromycin and several other drugs were effective. Many of the effective drugs were not known to be safe during pregnancy, other than azithromycin, daptomycin and sofosbuvir. However, compared to azithromycin and sofosbuvir, daptomycin showed less effectivity in various cell types in vitro. Azithromycin and sofosbuvir were shown to decrease infection from 78% to below 5%, whereas daptomycin only lowered it to 46%. The study notes that pending in vivo studies testing the safety and efficacy of all three drugs, azithromycin may be the antibiotic of choice due to its low cost and availability.
Read the UCSF publicity statement here: http://www.ucsf.edu/news/2016/11/405031/zika-fetal-brain-tissue-responds-popular-antibiotic
Read the actual study (published 11/29/16) here: http://www.pnas.org/content/early/2016/11/28/1618029113.abstract