Two vaccines against Zika virus developed at the University of Pittsburgh School of Medicine have successfully conveyed immunity from female mice to pups conceived weeks after the mother’s vaccination.
When challenged with Zika virus within a week of their birth, both vaccines protected the pups against neurological damage better than pups with no maternal-conferred immunity. The results are published online today and scheduled for the November issue of EBioMedicine, a journal supported by CellPress and The Lancet.
“We’ve not only developed a promising vaccine candidate to move toward larger preclinical and, eventually, human clinical trials, but also a delivery format that would be inexpensive to produce and distribute to hundreds of thousands of people,” said senior author Andrea Gambotto, M.D., associate professor of surgery in Pitt’s School of Medicine.
Zika is a virus spread primarily through the bite of an infected mosquito of the Aedes species. When pregnant women are infected, the virus can pass to their fetus, which can damage the developing baby and cause severe neurological birth defects, including microcephaly, or an abnormally small head.
One of the two vaccines uses a “microneedle array” to deliver the vaccine just below the surface of the skin through tiny crystals that dissolve after being affixed to the skin by a Band-Aid-like patch. The technology was co-invented by Louis D. Falo, M.D., Ph.D., chair of Pitt’s Department of Dermatology and co-author of the study.
The other vaccine uses the traditional needle delivery format and adenovirus, a type of common cold virus, to present Zika antigens to the immune system to induce immunity.
Both vaccines used proteins on the “envelope,” or outer shell, of the virus as the antigen to prime the immune system so it can quickly recognize and fight off the actual virus. This approach has worked in the past to develop West Nile, yellow fever and dengue vaccines.