Researchers at Washington University School of Medicine in St. Louis and Vanderbilt University School of Medicine in Nashville, Tenn., have pinpointed a human antibody that prevented Zika from infecting fetuses in mice.
The researchers identified the antibody, called ZIKV-117, after screening 29 anti-Zika antibodies from people who had recovered following a Zika infection. The antibody neutralized five Zika strains in the laboratory.
The researchers then gave the antibody to pregnant mice either one day before or one day after they were infected with Zika. In both cases, the Zika virus levels in the mice and their fetuses, as well as in their placenta, reduced as compared with pregnant mice that did not receive the antibody.
Additionally, the antibody protected adult male mice against Zika, even five days after the initial infection.
"These naturally occurring antibodies isolated from humans represent the first medical intervention that prevents Zika infection and damage to fetuses," said James Crowe Jr., MD, director of the Vanderbilt Vaccine Center and co-senior author.
The findings also suggest that a vaccine for adults that elicits protective antibodies will likely protect fetuses as well. Thus, pregnant women could protect their fetuses from the Zika's damaging effects, including microcephaly, by taking protective antibodies until researchers develop human vaccine. Nature published the study
In the United States, 25 babies have been born with Zika-related birth defects, and 1,005 pregnant women have lab evidence of possible Zika virus infection, according to the CDC's most recent updates.