A mother’s immune response to the Zika virus – and not the virus itself – may be responsible for birth defects and miscarriages, a new study has found.
Researchers exposed two groups of mice to the Zika virus. One group, bred to not have a key step in their immune responses, wound up giving birth to normal pups, while normal mice often either miscarried or gave birth to extremely underweight offspring.
“The antiviral response generated in response to Zika infection is causing the miscarriage of the fetus, as opposed to the virus itself,” said senior researcher Akiko Iwasaki, a professor of immunobiology at the Yale University School of Medicine and an investigator for the Howard Hughes Medical Institute, in Chevy Chase, Maryland.
The study’s initial theory was that the mice without a key signaling protein for the immune system would be at greater risk for Zika-caused miscarriages. As it turned out, the opposite was true.