An experimental Zika virus candidate developed at the Walter Reed Army Institute of Research prevented passage of the virus from mother to fetus, says a new study published in the journal npj Vaccines.

The collaborative preclinical study by Walter Reed with the Trudeau Institute and the Texas Biomedical Research Institute found neutralizing antibodies in fetal blood samples eight days after infection with the virus.

The vaccine was previously shown to be safe and to induce protection for nonpregnant individuals in a phase 1 study, but the investigators wanted to know if it is also safe and effective for pregnant women and their fetuses, said In-Jeong Kim, a lead investigator with the Trudeau Institute.

Read the full study report here: go.nature.com/3ocMQlf.