Desenvolvimento de técnica de RT-qPCR para detecção de hantavírus amazônicos

Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Resumo: A Síndrome Pulmonar por Hantavírus é uma zoonose emergente, muitas vezes fatal causada por hantavírus (família Bunyaviridae). A transmissão para humanos ocorre através do contato com excreta de roedores silvestres infectados. No Brasil, o diagnóstico para hantavírus é baseado em técnicas imunológicas, enquanto que RTPCR é utilizado como suporte laboratorial. O RT-qPCR tem sido utilizado no diagnóstico molecular de diversos agentes etiológicos, principalmente devido à geração rápida de resultados, junto com elevada sensibilidade e especificidade. No entanto, não há nenhum ensaio de RT-qPCR desenhado para detectar os hantavírus circulantes na Amazônia brasileira. Portanto, este estudo teve como objetivo o desenvolvimento de um ensaio de RT-qPCR controlado internamente para detectar esses hantavírus. Um conjunto de iniciadores e sonda foi desenhado a partir de uma região do gene N consenso, utilizando sequências dos hantavírus VLN, VANAJ, VCAS e VRIOM. Esta mesma região também foi clonada em plasmídeos e transcrita in vitro para RNA, o qual foi diluído em padrões de concentração conhecida. O RNA de bacteriófago MS2 foi adiconado em todas as amostras antes da extração e foi detectado em conjunto com hantavírus como um controle exógeno numa reacção duplex. Para avaliar os valores de sensibilidade, especificidade e acurácia do protocolo, foram testadas 127 amostras (de sangue ou soro), dividindo-se em três grupos: hantavírus positivo, hantavírus negativas e positivas para outros agentes patogênicos. Os resultados foram comparados aos obtidos por semi-nested RTPCR. A eficiência de RT-qPCR ficou em cerca de 100% e o limite de detecção foi de 0,9 cópias / mL de RNA. Não houve amplificação de ambos, as amostras negativas ou as amostras positivas de outros agentes patogénicos. O RT-qPCR foi mais sensível do que a semi-nested RT-PCR, sendo capaz de detectar três amostras não detectadas pelo semi-nested RT-PCR. A sensibilidade, especificidade e acurácia RT-qPCR valores foram de 92,5%, 100% e 97,63%, respectivamente. Assim, o ensaio de RT-qPCR desenvolvido foi específico, sensível e capaz de gerar resultados em duas horas, o que o torna um poderoso instrumento em aplicações de diagnóstico, vigilância e investigação de hantavirose na região da Amazônia brasileira e, possivelmente, para outros hantavíru

Using next generation sequencing to study the genetic diversity of candidate live attenuated zika vaccines

This research was funded in part by a Gillson-Longenbaugh Foundation grant to A.D.T.B. P.-Y.S. was supported in part by NIH grants AI142759, AI145617, AI127744, AI136126, and UL1TR001439, and awards from the Kleberg Foundation, John S. Dunn Foundation, Amon G. Carter Foundation, and Gillson-Longenbaugh Foundation.University of Texas Medical Branch. Department of Microbiology and Immunology. Galveston, TX, USA / Walter Reed Army Institute of Research. Viral Disease Branch. Silver Spring, MD, USA.University of Texas Medical Branch. Department of Biochemistry and Molecular Biology. Galveston, TX, USA / Chinese Academy of Sciences. Wuhan Institute of Virology. Wuhan, China.University of Texas Medical Branch. Department of Biochemistry and Molecular Biology. Galveston, TX, USA / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.University of Texas Medical Branch. Department of Biochemistry and Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity. Sealy Institute for Vaccine Sciences. Department of Pathology. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity. Sealy Institute for Vaccine Sciences. Department of Pathology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry and Molecular Biology. Galveston, TX, USA.Abstract: Zika virus (ZIKV) is a mosquito-transmitted positive-sense RNA virus in the family Flaviviridae. Candidate live-attenuated vaccine (LAV) viruses with engineered deletions in the 3’ untranslated region (UTR) provide immunity and protection in animal models of ZIKV infection, and phenotypic studies show that LAVs retain protective abilities following in vitro passage. The present study investigated the genetic diversity of wild-type (WT) parent ZIKV and its candidate LAVs using next generation sequencing analysis of five sequential in vitro passages. The results show that genomic entropy of WT ZIKV steadily increases during in vitro passage, whereas that of LAVs also increased by passage number five but was variable throughout passaging. Additionally, clusters of single nucleotide variants (SNVs) were found to be present in the pre-membrane/membrane (prM), envelope (E), nonstructural protein NS1 (NS1), and other nonstructural protein genes, depending on the specific deletion, whereas in the parent WT ZIKV, they are more abundant in prM and NS1. Ultimately, both the parental WT and LAV derivatives increase in genetic diversity, with evidence of adaptation following passage

Multiplexed reverse transcription real-time polymerase chain reaction for simultaneous detection of Mayaro, Oropouche, and Oropouche-like viruses

Submitted by Raphael Rodrigues ([email protected]) on 2017-06-13T14:33:21Z No. of bitstreams: 1 ve_Felipe_Gomes_Naveca_etal_ILMD_2017.pdf: 611276 bytes, checksum: 7e501740aec08f9832c2d20d41b9f4a9 (MD5)Approved for entry into archive by Raphael Rodrigues ([email protected]) on 2017-06-13T14:42:56Z (GMT) No. of bitstreams: 1 ve_Felipe_Gomes_Naveca_etal_ILMD_2017.pdf: 611276 bytes, checksum: 7e501740aec08f9832c2d20d41b9f4a9 (MD5)Made available in DSpace on 2017-06-13T14:42:56Z (GMT). No. of bitstreams: 1 ve_Felipe_Gomes_Naveca_etal_ILMD_2017.pdf: 611276 bytes, checksum: 7e501740aec08f9832c2d20d41b9f4a9 (MD5) Previous issue date: 2017Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Leônidas e Maria Deane. Manaus, AM, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Unversidade do Estado do Pará. Belém, PA, Brasil.We describe a sensitive method for simultaneous detection of Oropouche and Oropouche-like viruses carrying the Oropouche S segment, as well as the Mayaro virus, using a multiplexed one-step reverse transcription real-time polymerase chain reaction (RT-qPCR). A chimeric plasmid containing both Mayaro and Oropouche targets was designed and evaluated for the in vitro production of transcribed RNA, which could be easily used as a non-infectious external control. To track false-negative results due to PCR inhibition or equipment malfunction, the MS2 bacteriophage was also included in the multiplex assay as an internal positive control. The specificity of the multiplex assay was evaluated by Primer-Blast analysis against the entire GenBank database, and further against a panel of 17 RNA arboviruses. The results indicated an accurate and highly sensitive assay with amplification efficiency greater than 98% for both targets, and a limit of detection between two and 20 copies per reaction. We believe that the assay described here will provide a tool for Mayaro and Oropouche virus detection, especially in areas where differential diagnosis of Dengue, Zika and Chikungunya viruses should be performed

Underreporting of Dengue-4 in Brazil due to low sensitivity of the NS1 Ag test in routine control programs.

We have identified fifty-eight samples that were positive for Dengue-4 among 119 samples with negative diagnoses for dengue via the Platelia™ dengue NS1 Ag in Aracaju, State of Sergipe, Brazil. We determined that the low sensitivity of the NS1 Ag test could be related to secondary dengue infections in the studied population. Therefore, we concluded that the sensitivity and specificity of the Platelia™ dengue NS1 Ag test as a screening method for monitoring circulating dengue serotypes must be reevaluated. In addition, regional endo-epidemic profiles should also be considered due to the prevalence of secondary responses

Zika structural genes determine the virulence of African and Asian lineages

This work was supported by Amon G. Carter Foundation; Conselho Nacional de Desenvolvimento Científico e Tecnológico: [Grant Number 303999/2016-0,440405/2016-5]; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior: [Grant Number Zika fast track project]; John S. Dunn Foundation; Gilson Longenbaugh Foundation; NIH: [Grant Number AI127744,AI136126,AI142759];PAHO: [Grant Number SCON2016-01353]; Summerfield Robert Foundation; Robert J. Kleberg, Jr. and Helen C. Kleberg Foundation; Sealy & Smith Foundation.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Health Sciences Institute. Belem, PA, Brazil.Department of Biochemistry & Molecular Biology. Galveston, TX, USA.Department of Biochemistry & Molecular Biology. Galveston, TX, USA.Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Department of Microbiology & Immunology. Galveston, TX, USA.Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Health Sciences Institute. Belem, PA, Brazil.Health Sciences Institute. Belem, PA, Brazil / Federal University of Pará. Biological Sciences Institute. Belem, PA, Brazil.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Pará State University. Department of Pathology. Belém, PA, Brazil.Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Institute for Human Infections & Immunity. Galveston, TX, USA / Institute for Translational Science. Galveston, TX, USA / Sealy Institute of Vaccine Sciences. Galveston, TX, USA / Texas Medical Branch. Sealy Center for Structural Biology & Molecular Biophysics. Galveston, TX, USA.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Programa de Pós-Graduação em Virologia. Ananindeua, PA, Brasil / Health Sciences Institute. Belém, PA, Brazil.The Asian lineage of Zika virus (ZIKV) is responsible for the recent epidemics in the Americas and severe disease, whereas the African lineage of ZIKV has not been reported to cause epidemics or severe disease. We constructed a cDNA infectious clone (IC) of an African ZIKV strain, which, together with our previously developed Asian ZIKV strain IC, allowed us to engineer chimeric viruses by swapping the structural and non-structural genes between the two lineages. Recombinant parental and chimeric viruses were analyzed in A129 and newborn CD1 mouse models. In the A129 mice, the African strain developed higher viremia, organ viral loading, and mortality rate. In CD1 mice, the African strain exhibited a higher neurovirulence than the Asian strain. A chimeric virus containing the structural genes from the African strain is more virulent than the Asian strain, whereas a chimeric virus containing the non-structural genes from the African strain exhibited a virulence comparable to the Asian strain. These results suggest that (i) African strain is more virulent than Asian strain and (ii) viral structural genes primarily determine the virulence difference between the two lineages in mouse models. Other factors may contribute to the discrepancy between the mouse and epidemic results

Role of mutational reversions and fitness restoration in Zika virus spread to the Americas

University of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity. Department of Biochemistry and Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry and Molecular Biology and Institute for Human Infections and Immunity. Galveston, TX, USA.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.University of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.University of Texas Medical Branch. Department of Preventive Medicine and Community Health. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.University of Texas Medical Branch. Department of Pathology, Center for Biodefense and Emerging Infectious Diseases, World Reference Center for Emerging Viruses and Arboviruses, and Institute for Human Infections and Immunity, , Galveston, TX, USAUniversity of Texas Medical Branch. Department of Biochemistry and Molecular Biology and Institute for Human Infections and Immunity. Galveston, TX, USAUniversity of Texas Medical Branch. Institute for Human Infections and Immunity, and Department of Microbiology and Immunology. World Reference Center for Emerging Viruses and Arboviruses. Galveston, TX, USA.Zika virus (ZIKV) emerged from obscurity in 2013 to spread from Asia to the South Pacific and the Americas, where millions of people were infected, accompanied by severe disease including microcephaly following congenital infections. Phylogenetic studies have shown that ZIKV evolved in Africa and later spread to Asia, and that the Asian lineage is responsible for the recent epidemics in the South Pacific and Americas. However, the reasons for the sudden emergence of ZIKV remain enigmatic. Here we report evolutionary analyses that revealed four mutations, which occurred just before ZIKV introduction to the Americas, represent direct reversions of previous mutations that accompanied earlier spread from Africa to Asia and early circulation there. Our experimental infections of Aedes aegypti mosquitoes, human cells, and mice using ZIKV strains with and without these mutations demonstrate that the original mutations reduced fitness for urban, human-amplifed transmission, while the reversions restored fitness, increasing epidemic risk. These findings include characterization of three transmission-adaptive ZIKV mutations, and demonstration that these and one identified previously restored fitness for epidemic transmission soon before introduction into the Americas. The initial mutations may have followed founder effects and/or drift when the virus was introduced decades ago into Asia

Reverse transcriptase-semi-nested-polymerase chain reaction (RT-PCR) product in 2% agarose gel stained with syber safe.

<p>Lines 1–4: positive samples; 5–8: negative samples; 9–12: positive control for DENV-1, DENV-2, DENV-3 and DENV-4; NC: negative control; MW: molecular weight marker.</p

A live-attenuated Zika virus vaccine candidate induces sterilizing immunity in mouse models

P.-Y.S. was supported by a University of Texas Medical Branch (UTMB) start-up award, UTMB Innovation and Commercialization award, University of Texas STARs Award, CDC grant for the Western Gulf Center of Excellence for Vector-Borne Diseases, Pan American Health Organization grant SCON2016- 01353, and UTMB CTSA UL1TR-001439. This research was also partially supported by a US National Institutes of Health grant AI120942 to S.C.W.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Institute for Translational Sciences. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA / Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections &Immunity. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections &Immunity. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA.University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Institute for Translational Sciences. Galveston, TX, USA / University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Pará State University. Department of Pathology. Belém, PA, Brasil.University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Vaccine Development. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Structural Biology & Molecular Biophysics. Galveston, TX, USA / University of Texas Medical Branch. Department of Phamarcology & Toxicology. Galveston, TX, USA.Zika virus (ZIKV) infection of pregnant women can cause a wide range of congenital abnormalities, including microcephaly, in the infant, a condition now collectively known as congenital ZIKV syndrome. A vaccine to prevent or significantly attenuate viremia in pregnant women who are residents of or travelers to epidemic or endemic regions is needed to avert congenital ZIKV syndrome, and might also help to suppress epidemic transmission. Here we report on a live-attenuated vaccine candidate that contains a 10-nucleotide deletion in the 3' untranslated region of the ZIKV genome (10-del ZIKV). The 10-del ZIKV is highly attenuated, immunogenic, and protective in type 1 interferon receptor-deficient A129 mice. Crucially, a single dose of 10-del ZIKV induced sterilizing immunity with a saturated neutralizing antibody titer, which no longer increased after challenge with an epidemic ZIKV, and completely prevented viremia. The immunized mice also developed a robust T cell response. Intracranial inoculation of 1-d-old immunocompetent CD-1 mice with 1 × 104 infectious focus units (IFU) of 10-del ZIKV caused no mortality, whereas infections with 10 IFU of wild-type ZIKV were lethal. Mechanistically, the attenuated virulence of 10-del ZIKV may be due to decreased viral RNA synthesis and increased sensitivity to type-1-interferon inhibition. The attenuated 10-del ZIKV was incapable of infecting mosquitoes after oral feeding of spiked-blood meals, representing an additional safety feature. Collectively, the safety and efficacy results suggest that further development of this promising, live-attenuated ZIKV vaccine candidate is warranted

Emergence of a New Strain of DENV-2 in South America: Introduction of the Cosmopolitan Genotype through the Brazilian-Peruvian Border

Dengue virus 2 (DENV-2) seriously contributes to dengue-related mortality. It includes five nonsylvatic genotypes, with cosmopolitan being the most widespread with a significant contribution to the total number of DENV-2 cases globally. In South America, the cosmopolitan genotype was first recorded in 2019 in Madre de Dios, Peru, and then in Goiás (Midwest Brazil) in November 2021. In this study, we tested 163 human serum samples from Acre (Northern Brazil) collected during a DENV outbreak between 2020 and 2021 for all DENV genotypes by RT-qPCR. Of the 163 samples, 139 were positive for DENV-2, and 5 were positive for DENV-1. Five DENV-2-positive samples from early 2021 were sequenced, and the sequences clustered with the three other DENV-2 cosmopolitan genotype sequences already recorded on the continent. These results create a geographical link, suggesting the possible route of introduction of the DENV-2 cosmopolitan genotype into Brazil through the border with Peru, from which it may have dispersed to Midwest Brazil

A single-dose live-attenuated Zika Virus vaccine with controlled infection rounds that protects against vertical transmission

The P.-Y.S. lab was supported by a Kleberg Foundation Award and NIH grant AI127744. This research was also partially supported by NIH grant AI120942 to S.C.W. and by Cooperative Agreement Number U01CK000512 to S.C.W., funded by the CDCUniversity of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Virology and Chemoth. KU Leuven. Leuven, Belgium.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Virology and Chemoth. KU Leuven. Leuven, Belgium.University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA.University of Texas Medical Branch. Institute for Human Infections & Immunity. Galveston, TX, USA / University of Texas Medical Branch. Institute for Translational Sciences. Galveston, TX, USA / University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA / University of Texas Medical Branch. Sealy Institute for Vaccine Sciences. Galveston, TX, USA.University of Leuven. Rega Institute for Medical Research. Department of Microbiology and Immunology. Laboratory of Virology and Chemoth. KU Leuven. Leuven, Belgium.University of Texas Medical Branch. Department of Microbiology & Immunology. Galveston, TX, USA / University of Texas Medical Branch. Department of Pathology and Center for Biodefense & Emerging Infectious Diseases. Galveston, TX, USA / University of Texas Medical Branch. Sealy Institute for Vaccine Sciences. Galveston, TX, USA.Ministério da Saúde. Secretaria de Vigilância em Saúde. Instituto Evandro Chagas. Ananindeua, PA, Brasil / Pará State University. Department of Pathology. Belém, PA, Brazil.University of Texas Medical Branch. Department of Biochemistry & Molecular Biology. Galveston, TX, USA / University of Texas Medical Branch. Sealy Institute for Vaccine Sciences. Galveston, TX, USA / University of Texas Medical Branch. Sealy Center for Structural Biology & Molecular Biophysics. Galveston, TX, USA / University of Texas Medical Branch. Department of Pharmacology & Toxicology. Galveston, TX, USA.Zika virus (ZIKV) infection of the mother during pregnancy causes devastating Zika congenital syndrome in the offspring. A ZIKV vaccine with optimal safety and immunogenicity for use in pregnant women is critically needed. Toward this goal, we have developed a single-dose live-attenuated vaccine candidate that infects cells with controlled, limited infection rounds. The vaccine contains a 9-amino-acid deletion in the viral capsid protein and replicates to titers of > 10 6 focus-forming units (FFU)/mL in cells expressing the full-length capsid protein. Immunization of A129 mice with one dose (10 5 FFU) did not produce viremia, but elicited protective immunity that completely prevented viremia, morbidity, and mortality after challenge with an epidemic ZIKV strain (10 6 PFU). A single-dose vaccination also fully prevented infection of pregnant mice and maternal-to-fetal transmission. Intracranial injection of the vaccine (10 4 FFU) to 1-day-old mice did not cause any disease or death, underscoring the safety of this vaccine candidate