scholarly journals Seroprevalence of Toscana Virus and Sandfly Fever Sicilian Virus in European Bat Colonies Measured Using a Neutralization Test

Viruses ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 88
Author(s):  
Nazli Ayhan ◽  
Marc López-Roig ◽  
Abir Monastiri ◽  
Remi N. Charrel ◽  
Jordi Serra-Cobo
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Mediterranean Area ◽  
Convincing Evidence ◽  
Natural Cycle ◽  
Prevalence Rates ◽  
Toscana Virus ◽  
Myotis Myotis ◽  
Capture Recapture ◽  
Eptesicus Serotinus

Toscana phlebovirus (TOSV) and Sicilian phlebovirus (SFSV) are endemic in the Mediterranean area where they are transmitted to humans by infected sandflies. Vertebrates of several species have been postulated to act as reservoirs of these viruses, but convincing evidence is still awaited. Among them, bats have been suggested, however documented evidence is lacking. Here we tested a total of 329 bats belonging to eight species collected from twelve localities in southern Spain for the presence of neutralizing antibodies specific to TOSV and SFSV. Positive sera were detected in Schreiber’s long-fingered bat (Miniopterus schreibersii), mouse-eared Myotis (Myotis myotis), European free-tailed bat (Tadarida teniotis), and common serotine (Eptesicus serotinus) with the latter showing the highest prevalence rates for SFSV (22.6%) and TOSV (10%). There was no difference between females and males. Results suggest that bats are not likely to play a major role in the natural cycle of these two sandfly-borne phleboviruses. However, large breeding colonies of bats can be used as sentinels for surveillance of the presence of such viruses in a given locality. In addition, capture–recapture studies should be initiated in order to understand better the dynamics of TOSV and SFSV in bat populations.

scholarly journals Five Commercial Immunoassays for SARS-CoV-2 Antibody Determination and Their Comparison and Correlation with the Virus Neutralization Test

Diagnostics ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 593
Author(s):  
Václav Šimánek ◽  
Ladislav Pecen ◽  
Zuzana Krátká ◽  
Tomáš Fürst ◽  
Hana Řezáčková ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Young Patients ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Age Dependent ◽  
Previous Contact ◽  
Dependent Elderly ◽  
Protein Assays ◽  
Antibody Determination

There is an ongoing debate as to whether SARS-CoV-2 antibodies can be found in patients who have recovered from COVID-19 disease. Currently, there is no consensus on whether the antibodies, if present, are protective. Our regular measurements of SARS-CoV-2 antibodies, starting in July 2020, have provided us with the opportunity of becoming acquainted with the five different immunoassays. A total of 149 patients were enrolled in our study. We measured the samples using each immunoassay, then performing a virus neutralization test and comparing the results of SARS-CoV-2 antibodies with this test. We observed that the production of neutralizing antibodies is age-dependent. Elderly patients have a higher proportion of high neutralizing titers than young patients. Based on our results, and in combination with the literature findings, we can conclude that the serological SARS-CoV-2 antibody measurement is a helpful tool in the fight against COVID-19. The assays can provide information about the patient’s previous contact with the virus. Anti-spike protein assays correlate well with the virus neutralization test and can be used in the screening of potential convalescent plasma donors.

scholarly journals Development of SARS-CoV-2 Specific IgG and Virus-Neutralizing Antibodies after Infection with Variants of Concern or Vaccination

Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 700
Author(s):  
Franziska Neumann ◽  
Ruben Rose ◽  
Janine Römpke ◽  
Olaf Grobe ◽  
Thomas Lorentz ◽  
...  
Keyword(s):  
Immune Response ◽  
Receptor Binding ◽  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Vaccine Dose ◽  
High Avidity ◽  
Receptor Binding Domain ◽  
Robust Immune Response ◽  
Specific Igg ◽  
Nucleoprotein N

The humoral immunity after SARS-CoV-2 infection or vaccination was examined. Convalescent sera after infection with variants of concern (VOCs: B.1.1.7, n = 10; B.1.351, n = 1) and sera from 100 vaccinees (Pfizer/BioNTech, BNT162b2, n = 33; Moderna, mRNA-1273, n = 11; AstraZeneca, ChAdOx1 nCoV-19/AZD1222, n = 56) were tested for the presence of immunoglobulin G (IgG) directed against the viral spike (S)-protein, its receptor-binding domain (RBD), the nucleoprotein (N) and for virus-neutralizing antibodies (VNA). For the latter, surrogate assays (sVNT) and a Vero-cell based neutralization test (cVNT) were used. Maturity of IgG was determined by measuring the avidity in an immunoblot (IB). Past VOC infection resulted in a broad reactivity of anti-S IgG (100%), anti-RBD IgG (100%), and anti-N IgG (91%), while latter were absent in 99% of vaccinees. Starting approximately two weeks after the first vaccine dose, anti-S IgG (75–100%) and particularly anti-RBD IgG (98–100%) were detectable. After the second dose, their titers increased and were higher than in the convalescents. The sVNT showed evidence of VNA in 91% of convalescents and in 80–100%/100% after first/second vaccine dose, respectively. After the second dose, an increase in VNA titer and IgGs of high avidity were demonstrated by cVNT and IB, respectively. Re-vaccination contributes to a more robust immune response.

scholarly journals Seroprevalence and correlates of SARS-CoV-2 neutralizing antibodies from a population-based study in Bonn, Germany

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
N. Ahmad Aziz ◽  
Victor M. Corman ◽  
Antje K. C. Echterhoff ◽  
Marcel A. Müller ◽  
Anja Richter ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Response Rate ◽  
Neutralization Test ◽  
Population Based ◽  
Immunofluorescence Assay ◽  
Test Results ◽  
Community Based ◽  
Population Based Study ◽  
Temporal Course ◽  
Confirmatory Tests

AbstractTo estimate the seroprevalence and temporal course of SARS-CoV-2 neutralizing antibodies, we embedded a multi-tiered seroprevalence survey within an ongoing community-based cohort study in Bonn, Germany. We first assessed anti-SARS-CoV-2 immunoglobulin G levels with an immunoassay, followed by confirmatory testing of borderline and positive test results with a recombinant spike-based immunofluorescence assay and a plaque reduction neutralization test (PRNT). Those with a borderline or positive immunoassay result were retested after 4 to 5 months. At baseline, 4771 persons participated (88% response rate). Between April 24th and June 30th, 2020, seroprevalence was 0.97% (95% CI: 0.72−1.30) by immunoassay and 0.36% (95% CI: 0.21−0.61) when considering only those with two additional positive confirmatory tests. Importantly, about 20% of PRNT+ individuals lost their neutralizing antibodies within five months. Here, we show that neutralizing antibodies are detectable in only one third of those with a positive immunoassay result, and wane relatively quickly.

scholarly journals A GFP Reporter MR766-Based Flow Cytometry Neutralization Test for Rapid Detection of Zika Virus-Neutralizing Antibodies in Serum Specimens

Vaccines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 66 ◽  
Author(s):  
Frumence ◽  
Viranaicken ◽  
Gadea ◽  
Desprès
Keyword(s):  
Flow Cytometry ◽  
Zika Virus ◽  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Health Concern ◽  
Structural Protein ◽  
Adult Mice ◽  
Gfp Reporter ◽  
Infected Cells ◽  
High Level

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.

scholarly journals Evidence of neutralizing antibodies against SARS-CoV-2 in domestic cats living with owners with a history of COVID-19 in Lima, Peru

2021 ◽  
Author(s):  
Luis M. Jara ◽  
Cusi Ferradas ◽  
Francesca Schiaffino ◽  
Camila Sanchez-Carrion ◽  
Ana Martinez ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Domestic Animals ◽  
Disease Prevalence ◽  
Receptor Binding Domain ◽  
Domestic Cats ◽  
Viral Reservoirs ◽  
History Of ◽  
Community Transmission ◽  
Disease Exposure

SARS-CoV-2 can infect a variety of wild and domestic animals worldwide. Of these, domestic cats are highly susceptible species and potential viral reservoirs. As such, it is important to investigate disease exposure in areas with active community transmission and high disease prevalence. In this report we demonstrate the presence of serum neutralizing antibodies against the receptor binding-domain (RBD) of the SARS-CoV-2 in cats whose owners had been infected with SARS-CoV-2 in Lima, Peru, using a commercial competitive ELISA SARS-CoV-2 Surrogate Virus Neutralization Test. Out of 41 samples, 17.1% (7/41) and 31.7% (13/41) were positive, using the cut-off inhibition value of 30% and 20%, respectively. Not all cats living in a single house had detectable neutralizing antibodies showing that heterogenous exposure and immune among cohabiting animals. This is the first report of SARS-COV-2 exposure of domestic cats in Lima, Peru. Further studies are required to ascertain the prevalence of SARS-COV-2 exposure among domestic cats of Lima, Peru.

scholarly journals Molecular and seroepidemiologic studies of Enterovirus 71 infection in the State of Pará, Brazil

2005 ◽  
Vol 47 (2) ◽  
pp. 65-71 ◽  
Author(s):  
Ceyla M.O. Castro ◽  
Ana Cecília R. Cruz ◽  
Edson E. da Silva ◽  
Maria de Lourdes C. Gomes
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Neurological Diseases ◽  
Enterovirus 71 ◽  
Foot And Mouth Disease ◽  
Northern Region ◽  
Molecular Pattern ◽  
Seroepidemiologic Studies ◽  
Stool Samples ◽  
The City

In many countries, the Enterovirus 71 (EV-71) Picornaviridae family is associated to hand, foot and mouth disease in addition to acute neurological diseases while in Brazil these viruses are more closely associated to the latter group. The aim of this research was to use the first EV-71 isolate of the Northern region of Brazil in molecular and seroepidemiologic studies. Two (2.2%) out of 88 stool samples (44 cases of AFP), collected from January 1998 to December 2000 were positive for EV-71 isolation (73442/PA/99). Nucleotide sequence of the gen that codifies the VP1 protein showed that isolate 73442/PA/99 was similar to the EV-71 strains belonging to genotype B - more closely identified with EV-71 from North America. Neutralization test with 389 sera samples collected from January 1998 to November 2001, from individuals ranging from 0 to 15 years of age living in the city of Belém, State of Pará showed the following results in relation to isolate 73442/PA/99 and prototype BrCr: a total of 207 individuals (53.2%) had neutralization antibodies to both viruses, 167 (42.9%) had no antibodies and 15 showed the presence of neutralizing antibodies to one of the two viruses. Only 20.2% of the children aged 0 to 3 had neutralizing antibodies to EV-71, indicating that these children were more susceptible to the infection. Both the seroprevalence study and VP1 sequencing were important to demonstrate the spread and the molecular pattern of the EV-71 circulating in the Northern Region of Brazil.

scholarly journals Development of specific immunity in laboratory animals after co-immunization against seasonal influenza and COVID-19

2022 ◽  
Vol 98 (6) ◽  
pp. 648-656
Author(s):  
G. M. Ignatyev ◽  
I. A. Leneva ◽  
A. V. Atrasheuskaya ◽  
L. I. Kozlovskaya ◽  
N. P. Kartashova ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Seasonal Influenza ◽  
Neutralization Test ◽  
Elisa Test ◽  
Control Measures ◽  
Laboratory Animals ◽  
Enzyme Linked Immunosorbent Assay ◽  
Post Vaccination ◽  
Specific Immunity ◽  
Influenza Prevention

Introduction. In clinical practice, the differential diagnosis of COVID-19 can be challenging during the flu season, entailing serious consequences such as delays in appropriate control measures against the SARS-CoV-2 pandemic. Another problem is posed by co-infection of SARS-CoV-2 and influenza virus (IV), which significantly contributes to the severity of the COVID-19 disease. This study was aimed to explore the cross-impact of co-administration of Russian influenza and COVID-19 vaccines on development of specific immunity in laboratory animals.Materials and methods. The study was conducted on BALB/c mice. The animals were inoculated intramuscularly with the vaccine for COVID-19 prevention (CoviVac) and the vaccine for influenza prevention (Flu-M). The sera from the immunized animals were examined separately. Three IV strains were used in the hemagglutination inhibition assay. Antibodies (Abs) against SARS-CoV-2 were detected by an enzyme-linked immunosorbent assay (ELISA). The neutralization test was performed to detect virus neutralizing antibodies against SARS-CoV-2 and IV.Results. Relatively high titers of specific Abs were found in the groups of animals inoculated with one vaccine and with two vaccines concurrently. In the groups of animals inoculated with CoviVac and with two vaccines concurrently, both in the ELISA test and in the neutralization test, the average titers of specific Abs against SARSCoV- 2 did not demonstrate any statistical difference. The group of animals inoculated concurrently with two vaccines demonstrated statistically higher titers of Abs against IV after the second immunization compared to the group of animals inoculated with Flu-M.Discussion. The study has shown that post-vaccination immunity both to IV and to SARS-CoV-2 develops after co-vaccination with two vaccines. The observed enhanced post-vaccination immune response to IV in the coimmunized laboratory animals needs further research.Conclusion. The performed studies suggest the possibility of co-administration of two vaccines to prevent influenza and COVID-19.

Serological Responses in Patients Infected with Mayaro Virus and Evaluation of Cross-Protective Responses against Chikungunya Virus

2021 ◽  
Author(s):  
Nathen E. Bopp ◽  
Kara J. Jencks ◽  
Crystyan Siles ◽  
Carolina Guevara ◽  
Stalin Vilcarromero ◽  
...  
Keyword(s):  
Latin America ◽  
South America ◽  
Neutralizing Antibodies ◽  
Chikungunya Virus ◽  
Neutralization Test ◽  
Close Relative ◽  
Previous Exposure ◽  
Chikv Infection ◽  
The Caribbean ◽  
Mayaro Virus

Mayaro virus (MAYV) is an alphavirus endemic to both Latin America and the Caribbean. Recent reports have questioned the ability of MAYV and its close relative, Chikungunya virus (CHIKV), to generate cross-reactive, neutralizing antibodies to one another. Since CHIKV was introduced to South America in 2013, discerning whether individuals have cross-reactive antibodies or whether they have had exposures to both viruses previously has been difficult. Using samples obtained from people infected with MAYV prior to the introduction of CHIKV in the Americas, we performed neutralizing assays and observed no discernable neutralization of CHIKV by sera from patients previously infected with MAYV. These data suggest that a positive CHIKV neutralization test cannot be attributed to prior exposure to MAYV and that previous exposure to MAYV may not be protective against a subsequent CHIKV infection.

scholarly journals Effect of a booster-dose of rabies vaccine on the duration of virus neutralizing antibody titers in bovines

1998 ◽  
Vol 31 (4) ◽  
pp. 367-371 ◽  
Author(s):  
Avelino Albas ◽  
Paulo Eduardo Pardo ◽  
Albério Antonio Barros Gomes ◽  
Fernanda Bernardi ◽  
Fumio Honma Ito
Keyword(s):  
Immune Response ◽  
Neutralizing Antibodies ◽  
Booster Dose ◽  
Neutralization Test ◽  
Neutralizing Antibody ◽  
Rabies Vaccine ◽  
Western Region ◽  
Humoral Immune ◽  
Paulo State ◽  
Antibody Titers

Humoral immune response using inactivated rabies vaccine was studied in 35 nelore cross-bred bovines of western region of São Paulo state. Ninety days after vaccination, 13 (92.8%) animals presented titers 30.5IU/ml, through mouse neutralization test. After 180 days, 9 (64.3%) sera showed titers 30.5IU/ml, after 270 days, only one (7.1%) showed a titer of 0.51IU/ml, and after 360 days, all animals showed titers < 0.5IU/ml. Group of animals receiving booster dose 30 days after vaccination presented, two months after, all with titers > 0.5IU/ml. At 180 days, 17 (80.9%) sera presented titers > 0.5IU/ml; at 270 days, 15 (71.4%), with titers 30.5IU/ml and at 360 days, 4 (19.0%), with titers 30.5IU/ml. Booster-dose ensured high levels of neutralizing antibodies for at least three months, and 240 days after revaccination, 71.4% of animals were found with titers 30.5IU/ml.

scholarly journals Evaluation of a Novel Reporter Virus Neutralization Test for Serological Diagnosis of Zika and Dengue Virus Infection

2017 ◽  
Vol 55 (10) ◽  
pp. 3028-3036 ◽  
Author(s):  
Chao Shan ◽  
Daniel A. Ortiz ◽  
Yujiao Yang ◽  
Susan J. Wong ◽  
Laura D. Kramer ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Neutralizing Antibodies ◽  
Neutralization Test ◽  
Reference Method ◽  
Laboratory Diagnosis ◽  
Virus Neutralization Test ◽  
Virus Neutralization ◽  
Enzyme Linked Immunosorbent Assay ◽  
Reporter Virus ◽  
Screening Assay

ABSTRACT Currently, the laboratory diagnosis of Zika virus (ZIKV) infection is primarily through the detection of ZIKV RNA or antibodies against ZIKV proteins. The detection of viral RNA is highly sensitive and specific, but periods of viremia and viruria are brief, limiting the utility of ZIKV RNA assays. Instead, most ZIKV infections are diagnosed serologically, using an IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for screening, followed by a confirmatory plaque reduction neutralization test (PRNT). Typical turnaround times vary, due to assay incubation periods and a lack of clinical laboratories performing these tests. Recently, a novel luciferase-ZIKV- and -dengue virus (DENV)-based serological assay, which considerably improves the turnaround times and throughput for ZIKV diagnosis, was described. Using the traditional PRNT as a reference method, we evaluated the performance characteristics of the reporter virus neutralization test (RVNT) with 258 clinical serum specimens. The ZIKV RVNT produced primary ZIKV screening and secondary confirmation results in 4 days, with 100% reproducibility. As a screening assay, the ZIKV RVNT displayed excellent diagnostic accuracy, sensitivity, and specificity of 98.2%, 100%, and 98.1%, respectively. As a confirmatory assay, the ZIKV RVNT titers displayed 93.1% agreement with the traditional ZIKV PRNT titers. Overall, the RVNT accurately and reliably detects neutralizing antibodies in patient serum specimens, with improved turnaround times, and can be used for the serological detection of ZIKV infections. Due to the homogeneous 96-well format, the RVNT has also significantly improved the assay throughput to allow testing of a large number of specimens in a single run.

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