Since it emerged in Brazil in May 2015, the mosquito-borne Zika virus (ZIKV)
has raised global concern due to its association with a significant rise in the
number of infants born with microcephaly and neurological disorders such as
Guillain-Barré syndrome. We developed prototype subunit and adenoviralbased
Zika vaccines encoding the extracellular portion of the ZIKV envelope
gene (E) fused to the T4 fibritin foldon trimerization domain (Efl). The subunit
vaccine was delivered intradermally through carboxymethyl cellulose
microneedle array (MNA). The immunogenicity of these two vaccines, named
Ad5.ZIKV-Efl and ZIKV-rEfl, was tested in C57BL/6 mice. Prime/boost
immunization regimen was associated with induction of a ZIKV-specific
antibody response, which provided neutralizing immunity. Moreover,
protection was evaluated in seven-day-old pups after virulent ZIKV
intraperitoneal challenge. Pups born to mice immunized with Ad5.ZIKV-Efl
were all protected against lethal challenge infection without weight loss or
neurological signs, while pups born to dams immunized with MNA-ZIKV-rEfl
were partially protected (50%). No protection was seen in pups born to
phosphate buffered saline-immunized mice. This study illustrates the
preliminary efficacy of the E ZIKV antigen vaccination in controlling ZIKV
infectivity, providing a promising candidate vaccine and antigen format for the
prevention of Zika virus disease.