Researchers have found that a single dose of a particular human antibody can successfully prevent death in mice who have been infected with the Zika virus. Moreover, the antibody protected mouse fetuses from the effects of Zika. The research, published in the November 7th Nature journal, could represent a breakthrough in the fight against Zika.
When a mother is infected with the Zika virus, babies infected in utero can develop microcephaly – an abnormally small head. Zika had spread across Brazil, Central America, and Mexico by the start of 2016, spreading to parts of the United States over the summer. In places such as Brazil, the virus left behind a trail of devastation, with thousands of babies diagnosed with microcephaly there by June of 2016. Many of the children born with microcephaly have developed respiratory problems as a result of Zika. Some of these respiratory issues have proven fatal.
On Monday, researchers from the Washington University School of Medicine in St. Louis and Vanderbilt University School of Medicine published their research showing that a human antibody, called ZIKV-117, prevents the transfer of the virus to fetuses in mice.
Michael Diamond, MD, PhD, and one of the study’s senior authors, explained “This is the first antiviral that has been shown to work in pregnancy to protect developing fetuses from Zika virus. This is proof of principle that Zika virus during pregnancy is treatable, and we already have a human antibody that treats it, at least in mice.”
The researchers, including Diamond and co-senior author James Crowe Jr., MD, of Vanderbilt, screened 28 antibodies from people who had been infected with Zika and recovered successfully. One of these antibodies, ZIKV-117, neutralized all five Zika strains in the lab setting. The researchers also gave the antibody to pregnant mice – some one day before, and some one day after they were infected with the Zika virus. In both scenarios, the antibody reduced levels of Zika in the pregnant mice and in their fetuses.
“These naturally occurring antibodies isolated from humans represent the first medical intervention that prevents Zika infection and damage to fetuses,” Crowe explained.
Placentas from the treated female mice also appeared to be healthy, while those from untreated females showed damage to the placental structure. This damage can slow fetal growth and lead to fetal death, both of which are associated with the Zika virus in humans.
Further research which show how successful this antibody will be in creating a treatment or vaccine.
“We know that Zika can persist in certain parts of the body, such as the eyes and the testes, where it can cause long-term damage, at least in mice. We showed that the antibody can prevent disease, and now we want to know whether it can clear persistent infection from those parts of the body.”