Zika virus (ZIKV) became a global threat due to its unprecedented outbreak and its association with congenital malformations such as microcephaly in developing fetuses and neonates. There are currently no effective vaccines or drugs available for the prevention or treatment of ZIKV infection. Although multiple vaccine platforms have been established, their effectiveness in preventing congenital microcephaly has not been addressed. Herein, we tested a subunit vaccine containing the 450 amino acids at the N-terminus of the ZIKV envelope protein (E90) in mouse models for either in utero or neonatal ZIKV infection. In one model, embryos of vaccinated dams were challenged with a contemporary ZIKV strain at embryonic day 13.5. The other model infects neonatal mice from vaccinated dams by direct injection of ZIKV into the developing brains. The vaccine led to a substantial reduction of ZIKV-infected cells measured in the brains of fetal or suckling mice, and successfully prevented the onset of microcephaly compared to unvaccinated controls. Furthermore, E90 could protect mice from ZIKV infection even at 140 days post-immunization. This work directly demonstrates that immunization of pregnant mice protects the developing brains of offspring both in utero and in the neonatal period from subsequent ZIKV infection and microcephaly. It also supports the further development of the E90 subunit vaccine towards clinical trials.

An aerosol jet printing-enabled dual-function biosensor for the sensitive detection of pathogens using SARS-CoV-2 RNA as an example has been developed. A CRISPR-Cas13:guide-RNA complex is activated in the presence of a target RNA, leading to the collateral trans-cleavage of ssRNA probes that contain a horseradish peroxidase (HRP) tag. This, in turn, catalyzes the oxidation of 3,3,5,5-tetramethylbenzidine (TMB) by HRP, resulting in a color change and electrochemical signal change. The colorimetric and electrochemical sensing protocol does not require complicated target amplification and probe immobilization and exhibits a detection sensitivity in the femtomolar range. Additionally, our biosensor demonstrates a wide dynamic range of 5 orders of magnitude. This low-cost aerosol inkjet printing technique allows for an amplification-free and integrated dual-function biosensor platform, which operates at physiological temperature and is designed for simple, rapid, and accurate point-of-care (POC) diagnostics in either low-resource settings or hospitals.

Zika virus (ZIKV) targets neural progenitor cells in the brain, attenuates cell proliferation, and leads to cell death. Here, we describe a role for the ZIKV protease NS2B-NS3 heterodimer in mediating neurotoxicity through cleavage of a host protein required for neurogenesis. Similar to ZIKV infection, NS2B-NS3 expression led to cytokinesis defects and cell death in a protease activity-dependent fashion. Among binding partners, NS2B-NS3 cleaved Septin-2, a cytoskeletal factor involved in cytokinesis. Cleavage of Septin-2 occurred at residue 306 and forced expression of a non-cleavable Septin-2 restored cytokinesis, suggesting a direct mechanism of ZIKV-induced neural toxicity. VIDEO ABSTRACT.

Zika virus (ZIKV) has become a global public health emergency due to its rapidly expanding range and its ability to cause severe congenital defects such as microcephaly. However, there are no FDA-approved therapies or vaccines against ZIKV infection. Through our screening of viral entry inhibitors, we found that chloroquine (CQ), a commonly used antimalarial and a FDA-approved drug that has also been repurposed against other pathogens, could significantly inhibit ZIKV infection in vitro, by blocking virus internalization. We also demonstrated that CQ attenuates ZIKV-associated morbidity and mortality in mice. Finally, we proved that CQ protects fetal mice from microcephaly caused by ZIKV infection. Our methodology of focusing on previously identified antivirals in screens for effectiveness against ZIKV proved to be a rapid and efficient means of discovering new ZIKV therapeutics. Selecting drugs that were previously FDA-approved, such as CQ, also improves the likelihood that they may more quickly reach stages of clinical testing and use by the public.

We report neurodevelopmental outcomes in 216 infants followed since the time of PCR-confirmed maternal Zika virus (ZIKV) infection in pregnancy during the Rio de Janeiro epidemic of 2015-2016 (refs. ^1,2). Neurodevelopment was assessed by Bayley Scales of Infant and Toddler Development, third edition (Bayley-III; cognitive, language and motor domains) in 146 children and through neurodevelopment questionnaires/neurological examinations in 70 remaining children. Complete eye exams (n = 137) and hearing assessments (n = 114) were also performed. Below-average neurodevelopment and/or abnormal eye or hearing assessments were noted in 31.5% of children between 7 and 32 months of age. Among children assessed by Bayley-III, 12% scored below -2 s.d. (score <70; a score of 100 ± 2 s.d. is the range) in at least one domain; and 28% scored between -1 and -2 s.d. in any domain (scores <85-70). Language function was most affected, with 35% of 146 children below average. Improved neurodevelopmental outcomes were noted in female children, term babies, children with normal eye exams and maternal infection later in pregnancy (P = 0.01). We noted resolution of microcephaly with normal neurodevelopment in two of eight children, development of secondary microcephaly in two other children and autism spectrum disorder in three previously healthy children in the second year of life.

Zika virus (ZIKV) has become a public health threat due to its global transmission and link to severe congenital disorders. The host immune responses to ZIKV infection have not been fully elucidated, and effective therapeutics are not currently available. Herein, we demonstrated that cholesterol-25-hydroxylase (CH25H) was induced in response to ZIKV infection and that its enzymatic product, 25-hydroxycholesterol (25HC), was a critical mediator of host protection against ZIKV. Synthetic 25HC addition inhibited ZIKV infection in vitro by blocking viral entry, and treatment with 25HC reduced viremia and conferred protection against ZIKV in mice and rhesus macaques. 25HC suppressed ZIKV infection and reduced tissue damage in human cortical organoids and the embryonic brain of the ZIKV-induced mouse microcephaly model. Our findings highlight the protective role of CH25H during ZIKV infection and the potential use of 25HC as a natural antiviral agent to combat ZIKV infection and prevent ZIKV-associated outcomes, such as microcephaly.