Less than two years after the Zika virus was linked to congenital birth defects such as microcephaly, vaccine candidates are undergoing Phase I trials. The Lancet reported on promising candidates in an article late last year.
The formalin inactivated virus vaccine is a proven technology and has been used against polio since the 1950s. In Phase I, this particular vaccine for Zika provided immunity in 92% of recipients. There were also results for two Zika DNA vaccines, though this type of vaccine has only been approved for veterinary use in the past and not for human beings.
The speed at which vaccine candidates have been developed since the initial linking of Zika to birth defects has been unprecedented. When rubella was first associated with congenital rubella syndrome, it took 30 years before an effective vaccine became available. New fast-track review designations and incentives for companies to develop specialized vaccines such as priority review vouchers, raise the hope that effective and safe candidates will get to market more quickly.
While further R&D is needed, these initial trials show progress and determination from companies to protect mothers and their newborns against Zika.
Photo Credit: Ueslei Marcelino for UNICEF