scholarly journals High correlation between Zika virus NS1 antibodies and neutralizing antibodies in selected serum samples from normal healthy Thais

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Wannapa Sornjai ◽  
Suwipa Ramphan ◽  
Nitwara Wikan ◽  
Prasert Auewarakul ◽  
Duncan R. Smith

Abstract Despite the widespread presence of the mosquito transmitted Zika virus (ZIKV) over much of Southeast Asia, the number of reported cases remains low. One possibility is that residents in Southeast Asia are immunologically protected, although the nature of any such protection remains unclear. This study sought to investigate the presence of antibodies directed to ZIKV NS1 protein in a selected sub-set of samples from a well characterized cohort of serum samples from normal, healthy Thais that had been previously characterized for the presence of neutralizing antibodies to ZIKV, DENV 1-4, and JEV. Because of similarities in molecular weight between the flavivirus E and NS1 proteins, an immunoblot system was established in which the NS1 antigen was not denatured, allowing detection of the dimer form of NS1, distinctly clear from the migration position of the E and NS1 monomer proteins. The results showed that antibodies to ZIKV NS1 protein were only detected in samples with ZIKV neutralizing antibodies (27/30 samples), and no sample (0/30) with a ZIKV plaque reduction neutralization test (PRNT)90 < 20 showed evidence of anti-ZIKV NS1 antibodies. The high correlation between the presence of ZIKV NS1 antibodies and ZIKV PRNT suggests that immunological protection against ZIKV infection in Thailand arises from prior exposure to ZIKV, and not through cross neutralization.

Author(s):  
Mya Myat Ngwe Tun ◽  
Daisuke Mori ◽  
Shahnaz Binti Sabri ◽  
Omar Kugan ◽  
Saliz Binti Shaharom ◽  
...  

Several Zika virus (ZIKV) seroprevalence studies have been conducted in Africa, Asia, Oceania, the Americas, and the Caribbean. However, studies on ZIKV seroprevalence are limited in Malaysia though several studies have shown that the disease is endemic in the Malaysian state of Sabah. To evaluate the seroprevalence of ZIKV infection, 818 serum samples were collected from febrile patients and healthy blood donors from the Kudat and Kota Kinabalu districts in Sabah from 2017 to 2018. They were screened for ZIKV infection by IgM and IgG ELISA, and positive ZIKV IgM samples were subjected to a 90% neutralization test for confirmation. Twenty-four (6% [95% CI 4 to 8]) confirmed and two (0.5% [95% CI 0.13 to 1.8]) probable ZIKV infections were detected among 400 febrile illness patients. Of 418 healthy blood donor samples, six (1.4% [95% CI 0.65 to 3]) were determined as confirmed ZIKV infections and six (1.4% [95% CI 0.65 to 3]) indicated probable ZIKV infection. This is the first study on the seroprevalence of ZIKV infections among patients and healthy blood donors in Sabah. Compared with previous studies in Malaysia, this study shows that the incidence of ZIKV infection has increased. It also suggests that a sero-surveillance system is essential to determine the circulation of ZIKV in Sabah, Malaysia.


2020 ◽  
Vol 94 (17) ◽  
Author(s):  
Anzhong Li ◽  
Miaoge Xue ◽  
Zayed Attia ◽  
Jingyou Yu ◽  
Mijia Lu ◽  
...  

ABSTRACT The nonstructural protein 1 (NS1) of several flaviviruses, including West Nile, dengue, and yellow fever viruses, is capable of inducing variable degrees of protection against flavivirus infection in animal models. However, the immunogenicity of NS1 protein of Zika virus (ZIKV) is less understood. Here, we determined the efficacy of ZIKV NS1-based vaccine candidates using two delivery platforms, methyltransferase-defective recombinant vesicular stomatitis virus (mtdVSV) and a DNA vaccine. We first show that expression of ZIKV NS1 could be significantly enhanced by optimizing the signal peptide. A single dose of mtdVSV-NS1-based vaccine or two doses of DNA vaccine induced high levels of NS1-specfic antibody and T cell immune responses but provided only partial protection against ZIKV viremia in BALB/c mice. In Ifnar1−/− mice, neither NS1-based vaccine provided protection against a lethal high dose (105 PFU) ZIKV challenge, but mtdVSV-NS1-based vaccine prevented deaths from a low dose (103 PFU) challenge, though they experienced viremia and body weight loss. We conclude that ZIKV NS1 alone conferred substantial, but not complete, protection against ZIKV infection. Nevertheless, these results highlight the value of ZIKV NS1 for vaccine development. IMPORTANCE Most Zika virus (ZIKV) vaccine research has focused on the E or prM-E proteins and the induction of high levels of neutralizing antibodies. However, these ZIKV neutralizing antibodies cross-react with other flaviviruses, which may aggravate the disease via an antibody-dependent enhancement (ADE) mechanism. ZIKV NS1 protein may be an alternative antigen for vaccine development, since antibodies to NS1 do not bind to the virion, thereby eliminating the risk of ADE. Here, we show that recombinant VSV and DNA vaccines expressing NS1, alone, confer partial protection against ZIKV infection in both immunocompetent and immunodeficient mice, highlighting the value of NS1 as a potential vaccine candidate.


Diagnostics ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1696
Author(s):  
Steev Loyola ◽  
Alfredo Huaman ◽  
Dina Popuche ◽  
Elizabeth Castillo ◽  
Julia S. Ampuero ◽  
...  

Zika virus (ZIKV) emerged and spread rapidly in South American countries during 2015. Efforts to diagnose ZIKV infection using serological tools were challenging in dengue-endemic areas because of antigenic similarities between both viruses. Here, we assessed the performance of an in-house developed IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) and the plaque reduction neutralization test (PRNT) to diagnose ZIKV infection. Acute and convalescent paired serum samples from 51 patients who presented with clinical symptoms suggestive of an arbovirus illness in dengue-endemic areas of Honduras, Venezuela, Colombia and Peru were used in the assessment. Samples were tested for ZIKV, dengue and chikungunya virus using a variety of laboratory techniques. The results for the ZIKV-RNA screening and seroconversion detected by the microneutralization test were used to construct a composite reference standard. The overall sensitivity and specificity for the MAC-ELISA were 93.5% and 100.0%, respectively. Contrastingly, the overall sensitivity and specificity for the PRNT were 96.8% and 95.0%, respectively. Restricting the analysis according to IgM or neutralizing antibodies against dengue, the performances of both serological assays were adequate. The findings of this study reveal that the MAC-ELISA and PRNT would provide initial reliable laboratory diagnostic assays for ZIKV infection in dengue-endemic areas.


2020 ◽  
Author(s):  
Co Thach Nguyen ◽  
Meng Ling Moi ◽  
Thi Quynh Mai Le ◽  
Thi Thu Thuy Nguyen ◽  
Thi Bich Hau Vu ◽  
...  

Abstract Background : Between 2016 and 2019, 265 cases of Zika virus (ZIKV) infection were reported in Vietnam, predominantly in southern Vietnam. In 2016, a case of ZIKV-associated microcephaly was confirmed in the Central Highlands, and several members of the infant’s family were confirmed to be infected with ZIKV. The study aims to determine the level of immunity to ZIKV in the general population of the ZIKV epidemic region. Methods: A total of 879 serum samples were collected from 801 participants between January 2017 and July 2018, during and after the ZIKV epidemic in Vietnam. The samples were tested for anti-ZIKV immunoglobulin M (IgM) and immunoglobulin G (IgG), and anti-dengue virus (DENV) IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Plaque-reduction neutralization test (PRNT) for ZIKV was performed on all samples, and for DENV on the samples that ZIKV neutralizing antibody positive. Results: A total of 83 (10.3%) participants had anti-ZIKV IgM. Of the 83, 6 were confirmed to be ZIKV antibodies positive using PRNT and anti-ZIKV IgG ELISA. Of the 718 participants who were anti-ZIKV IgM negative, a further 3 cases were confirmed as positive for antibodies against ZIKV. Of the 9 participants with ZIKV infection, 5 lived in the same village as the infant with ZIKV-associated microcephaly and the other 4 lived in 2 neighboring communes. Repeat samples were collected from the 83 ZIKV IgM positive participants 1.5 years after the first collection. No new cases of ZIKV infection were detected. In addition, 2 of 3 participants with anti-ZIKV NS1 IgG demonstrated a 4- to 8-fold increase in ZIKV neutralizing antibody titer. Conclusions: ZIKV was present in the area around Krong Buk, with the rate of ZIKV-specific antibodies was 1.1% in the community since at least 2016. While the low levels of circulation together with low seroprevalence suggests a limited outbreak in the region, the results also reflect on low levels of protective immunity to Zika within the population. These results provide a better understanding of the current ZIKV epidemic status in the region and demonstrate a need for implementation of more effective ZIKV infection control measures.


2020 ◽  
Author(s):  
Co Thach Nguyen ◽  
Meng Ling Moi ◽  
Thi Quynh Mai Le ◽  
Thi Thu Thuy Nguyen ◽  
Thi Bich Hau Vu ◽  
...  

Abstract Background : Between 2016 and 2019, 265 cases of Zika virus (ZIKV) infection were reported in Vietnam, predominantly in southern Vietnam. In 2016, a case of ZIKV-associated microcephaly was confirmed in the Central Highlands, and several members of the infant’s family were confirmed to be infected with ZIKV. The study aims to determine the level of immunity to ZIKV in the general population of the ZIKV epidemic region. Methods: A total of 879 serum samples were collected from 801 participants between January 2017 and July 2018, during and after the ZIKV epidemic in Vietnam. The samples were tested for anti-ZIKV immunoglobulin M (IgM) and immunoglobulin G (IgG), and anti-dengue virus (DENV) IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Plaque-reduction neutralization test (PRNT) for ZIKV was performed on all samples, and for DENV on the samples that ZIKV neutralizing antibody positive. Results: A total of 83 (10.3%) participants had anti-ZIKV IgM. Of the 83, 6 were confirmed to be ZIKV antibodies positive using PRNT and anti-ZIKV IgG ELISA. Of the 718 participants who were anti-ZIKV IgM negative, a further 3 cases were confirmed as positive for antibodies against ZIKV. Of the 9 participants with ZIKV infection, 5 lived in the same village as the infant with ZIKV-associated microcephaly and the other 4 lived in 2 neighboring communes. Repeat samples were collected from the 83 ZIKV IgM positive participants 1.5 years after the first collection. No new cases of ZIKV infection were detected. In addition, 2 of 3 participants with anti-ZIKV NS1 IgG demonstrated a 4- to 8-fold increase in ZIKV neutralizing antibody titer. Conclusions: ZIKV was present in the area around Krong Buk, with the rate of ZIKV-specific antibodies was 1.1% in the community since at least 2016. While the low levels of circulation together with low seroprevalence suggests a limited outbreak in the region, the results also reflect on low levels of protective immunity to Zika within the population. These results provide a better understanding of the current ZIKV epidemic status in the region and demonstrate a need for implementation of more effective ZIKV infection control measures.


2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Mayra R. Montecillo-Aguado ◽  
Alfredo E. Montes-Gómez ◽  
Julio García-Cordero ◽  
Josselin Corzo-Gómez ◽  
Héctor Vivanco-Cid ◽  
...  

Zika virus (ZIKV), an emerging mosquito-borne flavivirus, has quickly spread in many regions around the world where dengue virus (DENV) is endemic. This represents a major health concern, given the high homology between these two viruses, which can result in cross-reactivity. The aim of this study was to determine the cross-reacting antibody response of the IgM and IgG classes against the recombinant envelope protein of ZIKV (rE-ZIKV) in sera from patients with acute-phase infection of different clinical forms of dengue, i.e., dengue fever (DF) and dengue hemorrhagic fever (DHF) (before the arrival of ZIKV in Mexico 2010), as well as acute-phase sera of ZIKV patients, together with the implications in neutralization and antibody-dependent enhancement. Differences in IgM responses were observed in a number of DF and DHF patients whose sera cross-reacted with the rE-ZIK antigen, with 42% recognition between acute-phase DHF and ZIKV but 27% recognition between DF and ZIKV. Regarding IgG antibodies, 71.5% from the DF group showed cross-reactivity to rE-ZIKV in contrast with 50% and only 25% of DHF and ZIKV serum samples, respectively, which specifically recognized the homologous antigen. The DHF group showed more enhancement of ZIKV infection of FCRγ-expressing cells compared to the DF group. Furthermore, the DHF group also showed a higher cross-neutralizing ability than that of DF. This is the first report where DF and DHF serum samples were evaluated for cross-reactivity against Zika protein and ZIKV. Furthermore, DENV serum samples cross-protect against ZIKV through neutralizing antibodies but at the same time mediate antibody-dependent enhancement in the sequential ZIKV infection.


2020 ◽  
Author(s):  
Co Thach Nguyen ◽  
Meng Ling Moi ◽  
Thi Quynh Mai Le ◽  
Thi Thu Thuy Nguyen ◽  
Thi Bich Hau Vu ◽  
...  

Abstract Background: Between 2016 and 2019, 265 cases of Zika virus (ZIKV) infection were reported in Vietnam, predominantly in southern Vietnam. In 2016, a case of ZIKV-associated microcephaly was confirmed in the Central Highlands, and several members of the infant’s family were confirmed to be infected with ZIKV. However, data on the seroprevalence of ZIKV antibodies in the general population is limited. The purpose of this survey was to determine the level of immunity to ZIKV in the general population of the ZIKV epidemic region.Methods: A total of 879 serum samples were collected from 801 participants between January 2017 and July 2018, during and after the ZIKV epidemic in Vietnam. The samples were tested for anti-ZIKV immunoglobulin M (IgM) and immunoglobulin G (IgG), and anti-dengue virus (DENV) IgG antibodies using enzyme-linked immunosorbent assays (ELISA). Plaque-reduction neutralization test (PRNT) for ZIKV was performed on all samples, and for DENV on the samples that ZIKV neutralizing antibody positive.Results: A total of 83 (10.3%) participants had anti-ZIKV IgM. Of the 83, 6 were confirmed to be ZIKV positive using PRNT and anti-ZIKV IgG ELISA. Of the 718 participants who were anti-ZIKV IgM negative, a further 3 cases were confirmed to be ZIKV positive. Of the 9 participants with ZIKV infection, 5 lived in the same village as the infant with ZIKV-associated microcephaly and the other 4 lived in 2 neighboring communes. Repeat samples were collected from the 83 ZIKV IgM positive participants 1.5 years after the first collection. No new cases of ZIKV infection were detected. In addition, 2 of 3 participants with anti-ZIKV NS1 IgG demonstrated a 4- to 8-fold increase in ZIKV neutralizing antibody titer.Conclusion: ZIKV was present in the area around Krong Buk since at least 2016. While the low levels of circulation together with low seroprevalence suggests a limited outbreak in the region, the results also reflect on low levels of protective immunity to Zika within the population. These results provide a better understanding of the current ZIKV epidemic status in the region and demonstrate a need for implementation of more effective ZIKV infection control measures.


Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 66 ◽  
Author(s):  
Frumence ◽  
Viranaicken ◽  
Gadea ◽  
Desprès

Zika virus (ZIKV) is an emerging arthropod-borne virus of major public health concern. ZIKV infection is responsible for congenital Zika disease and other neurological defects. Antibody-mediated virus neutralization is an essential component of protective antiviral immunity against ZIKV. In the present study, we assessed whether our GFP reporter ZIKV derived from African viral strain MR766 could be useful for the development of a flow cytometry neutralization test (FNT), as an alternative to the conventional plaque-reduction neutralization test (PRNT). To improve the efficacy of GFP-expressing MR766, we selected virus variant MR766GFP showing a high level of GFP signal in infected cells. A MR766GFP-based FNT was assayed with immune sera from adult mice that received ZIKBeHMR-2. The chimeric ZIKV clone ZIKBeHMR-2 comprises the structural protein region of epidemic strain BeH819015 into MR766 backbone. We reported that adult mice inoculated with ZIKBeHMR-2 developed high levels of neutralizing anti-ZIKV antibodies. Comparative analysis between MR766GFP-based FNT and conventional PRNT was performed using mouse anti-ZIKBeHMR-2 immune sera. Indistinguishable neutralization patterns were observed when compared with PRNT50 and FNT50. We consider that the newly developed MR766GFP-based FNT is a valid format for measuring ZIKV-neutralizing antibodies in serum specimens.


Viruses ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1807
Author(s):  
Eri Nakayama ◽  
Yasuhiro Kawai ◽  
Satoshi Taniguchi ◽  
Jessamine E. Hazlewood ◽  
Ken-ichi Shibasaki ◽  
...  

Zika virus (ZIKV) infection during pregnancy causes a wide spectrum of congenital abnormalities and postnatal developmental sequelae such as fetal loss, intrauterine growth restriction (IUGR), microcephaly, or motor and neurodevelopmental disorders. Here, we investigated whether a mouse pregnancy model recapitulated a wide range of symptoms after congenital ZIKV infection, and whether the embryonic age of congenital infection changed the fetal or postnatal outcomes. Infection with ZIKV strain PRVABC59 from embryonic day 6.5 (E6.5) to E8.5, corresponding to the mid-first trimester in humans, caused fetal death, fetal resorption, or severe IUGR, whereas infection from E9.5 to E14.5, corresponding to the late-first to second trimester in humans, caused stillbirth, neonatal death, microcephaly, and postnatal growth deficiency. Furthermore, 4-week-old offspring born to dams infected at E12.5 showed abnormalities in neuropsychiatric state, motor behavior, autonomic function, or reflex and sensory function. Thus, our model recapitulated the multiple symptoms seen in human cases, and the embryonic age of congenital infection was one of the determinant factors of offspring outcomes in mice. Furthermore, maternal neutralizing antibodies protected the offspring from neonatal death after congenital infection at E9.5, suggesting that neonatal death in our model could serve as criteria for screening of vaccine candidates.


Author(s):  
Felix G. Delgado ◽  
Karina I. Torres ◽  
Jaime E. Castellanos ◽  
Consuelo Romero-Sánchez ◽  
Etienne Simon-Lorière ◽  
...  

The high level of dengue virus (DENV) seroprevalence in areas where Zika virus (ZIKV) is circulating and the cross-reactivity between these two viruses have raised concerns on the risk of increased ZIKV disease severity for patients with a history of previous DENV infection. To determine the role of DENV pre-immunity in ZIKV infection, we analysed the T and B cell responses against ZIKV in donors with or without previous DENV infection. Using PBMCs from donors living in an endemic area in Colombia, we have identified, by interferon (IFN)-&gamma; enzyme-linked immunospot (ELISPOT) assay, most of the immunodominant ZIKV T-cell epitopes in the non-structural proteins NS1, NS3 and NS5. Analyses of the T and B-cell responses in the same donors revealed a stronger T-cell response against peptides conserved between DENV and ZIKV, with a higher level of ZIKV-neutralizing antibodies in DENV-immune donors, in comparison with DENV-na&iuml;ve donors. Strikingly, the potential for antibody mediated enhancement of ZIKV infection was reduced in donors with sequential DENV and ZIKV infection in comparison with donors with DENV infection only. Altogether, these data suggest that individuals with DENV immunity present improved immune responses against ZIKV.


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