scholarly journals Comparison of Serological Assays for the Detection of SARS-CoV-2 Antibodies

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 713
Author(s):  
Joe James ◽  
Shelley Rhodes ◽  
Craig S. Ross ◽  
Paul Skinner ◽  
Samuel P. Smith ◽  
...  
Keyword(s):  
Severe Disease ◽  
Antibody Responses ◽  
Antibody Detection ◽  
Potential Utility ◽  
Healthy Individuals ◽  
Detection Rates ◽  
Antigen Elisa ◽  
Prior Infection ◽  
Antibody Tests ◽  
Biosafety Level

SARS-CoV-2 virus was first detected in late 2019 and circulated globally, causing COVID-19, which is characterised by sub-clinical to severe disease in humans. Here, we investigate the serological antibody responses to SARS-CoV-2 infection during acute and convalescent infection using a cohort of (i) COVID-19 patients admitted to hospital, (ii) healthy individuals who had experienced ‘COVID-19 like-illness’, and (iii) a cohort of healthy individuals prior to the emergence of SARS-CoV-2. We compare SARS-CoV-2 specific antibody detection rates from four different serological methods, virus neutralisation test (VNT), ID Screen® SARS-CoV-2-N IgG ELISA, Whole Antigen ELISA, and lentivirus-based SARS-CoV-2 pseudotype virus neutralisation tests (pVNT). All methods were able to detect prior infection with COVID-19, albeit with different relative sensitivities. The VNT and SARS-CoV-2-N ELISA methods showed a strong correlation yet provided increased detection rates when used in combination. A pVNT correlated strongly with SARS-CoV-2 VNT and was able to effectively discriminate SARS-CoV-2 antibody positive and negative serum with the same efficiency as the VNT. Moreover, the pVNT was performed with the same level of discrimination across multiple separate institutions. Therefore, the pVNT is a sensitive, specific, and reproducible lower biosafety level alternative to VNT for detecting SARS-CoV-2 antibodies for diagnostic and research applications. Our data illustrate the potential utility of applying VNT or pVNT and ELISA antibody tests in parallel to enhance the sensitivity of exposure to infection.

scholarly journals A survey of coxsackie A16 virus antibodies in human sera

1984 ◽  
Vol 93 (2) ◽  
pp. 205-212 ◽  
Author(s):  
G. E. D. Urquhart
Keyword(s):  
Spontaneous Abortion ◽  
Adult Female ◽  
Foot And Mouth Disease ◽  
Antibody Detection ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Detection Rates ◽  
Common Cause ◽  
Human Sera ◽  
Antibody Tests

SummaryA comparison of neutralizing and immunofluorescent (IF) IgG antibody tests in 18 sera from 10 cases of hand, foot and mouth disease (HFMD) showed a variety of responses but all sera taken more than one week after infection had both neutralizing and IF IgG antibodies.A survey of IF IgG antibody in 80 paediatric and 80 adult non-HFMD case sera gave antibody detection rates of 47·5% and 11·3% respectively. This difference could be attributed to a decline in IF IgG antibody with time after infection. Three point nine per cent of 2G sera from possible adult carditis cases had IF antibody suggesting that coxsackie A16 virus was not a common cause of adult carditis. Forty-eight point three per cent of 29 sera from cases of spontaneous abortion had detectable IF antibody, a rate similar to the paediatric sera and significantly greater than that in adult male (7·9%) and other adult female (13%) sera tested. This interesting observation requires further study.

scholarly journals De-Coding the Contributions of the Viral RNAs to Alphaviral Pathogenesis

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 771
Author(s):  
Autumn T. LaPointe ◽  
Kevin J. Sokoloski
Keyword(s):  
Host Response ◽  
Severe Disease ◽  
Review Article ◽  
Structural Proteins ◽  
Virulence Determinants ◽  
Healthy Individuals ◽  
Viral Rnas ◽  
Positive Sense ◽  
Identification And Characterization

Alphaviruses are positive-sense RNA arboviruses that are capable of causing severe disease in otherwise healthy individuals. There are many aspects of viral infection that determine pathogenesis and major efforts regarding the identification and characterization of virulence determinants have largely focused on the roles of the nonstructural and structural proteins. Nonetheless, the viral RNAs of the alphaviruses themselves play important roles in regard to virulence and pathogenesis. In particular, many sequences and secondary structures within the viral RNAs play an important part in the development of disease and may be considered important determinants of virulence. In this review article, we summarize the known RNA-based virulence traits and host:RNA interactions that influence alphaviral pathogenesis for each of the viral RNA species produced during infection. Overall, the viral RNAs produced during infection are important contributors to alphaviral pathogenesis and more research is needed to fully understand how each RNA species impacts the host response to infection as well as the development of disease.

scholarly journals A chemokine-fusion vaccine targeting immature dendritic cells elicits elevated antibody responses to malaria sporozoites in infant macaques

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kun Luo ◽  
James T. Gordy ◽  
Fidel Zavala ◽  
Richard B. Markham
Keyword(s):  
San Diego ◽  
Severe Disease ◽  
Antibody Responses ◽  
Poly I:C ◽  
Protein Vaccine ◽  
Primate Model ◽  
Polyinosinic:Polycytidylic Acid ◽  
Inflammatory Protein ◽  
Immature Dendritic Cells ◽  
High Concentrations

AbstractInfants and young children are the groups at greatest risk for severe disease resulting from Plasmodium falciparum infection. We previously demonstrated in mice that a protein vaccine composed of the chemokine macrophage inflammatory protein 3α genetically fused to the minimally truncated circumsporozoite protein of P. falciparum (MCSP) elicits high concentrations of specific antibody and significant reduction of liver sporozoite load in a mouse model system. In the current study, a squalene based adjuvant (AddaVax, InvivoGen, San Diego, Ca) equivalent to the clinically approved MF59 (Seqiris, Maidenhead, UK) elicited greater antibody responses in mice than the previously employed adjuvant polyinosinic:polycytidylic acid, ((poly(I:C), InvivoGen, San Diego, Ca) and the clinically approved Aluminum hydroxide gel (Alum, Invivogen, San Diego, Ca) adjuvant. Use of the AddaVax adjuvant also expanded the range of IgG subtypes elicited by mouse vaccination. Sera passively transferred into mice from MCSP/AddaVax immunized 1 and 6 month old macaques significantly reduced liver sporozoite load upon sporozoite challenge. Protective antibody concentrations attained by passive transfer in the mice were equivalent to those observed in infant macaques 18 weeks after the final immunization. The efficacy of this vaccine in a relevant non-human primate model indicates its potential usefulness for the analogous high risk human population.

scholarly journals Kinetics of Anti-SARS-CoV-2 Antibody Responses 3 Months Post Complete Vaccination with BNT162b2; A Prospective Study in 283 Health Workers

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1942
Author(s):  
Evangelos Terpos ◽  
Ioannis P. Trougakos ◽  
Vangelis Karalis ◽  
Ioannis Ntanasis-Stathopoulos ◽  
Sentiljana Gumeni ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Health Workers ◽  
Antibody Responses ◽  
Healthy Individuals ◽  
Younger Age ◽  
Constant Rate ◽  
Rate Of Decline ◽  
A Prospective Study ◽  
Kinetics Of ◽  
Over Time

The aim of this study was to investigate the kinetics of neutralizing antibodies (NAbs) and anti-SARS-CoV-2 anti-S-RBD IgGs up to three months after the second vaccination dose with the BNT162b2 mRNA vaccine. NAbs and anti-S-RBD levels were measured on days 1 (before the first vaccine shot), 8, 22 (before the second shot), 36, 50, and three months after the second vaccination (D111) (NCT04743388). 283 health workers were included in this study. NAbs showed a rapid increase from D8 to D36 at a constant rate of about 3% per day and reached a median (SD) of 97.2% (4.7) at D36. From D36 to D50, a slight decrease in NAbs values was detected and it became more prominent between D50 and D111 when the rate of decline was determined at −0.11 per day. The median (SD) NAbs value at D111 was 92.7% (11.8). A similar pattern was also observed for anti-S-RBD antibodies. Anti-S-RBDs showed a steeper increase during D22–D36 and a lower decline rate during D36–D111. Prior COVID-19 infection and younger age were associated with superior antibody responses over time. In conclusion, we found a persistent but declining anti-SARS-CoV-2 humoral immunity at 3 months following full vaccination with BNT162b2 in healthy individuals.

scholarly journals Infliximab is associated with attenuated immunogenicity to BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines in patients with IBD

Gut ◽  
2021 ◽  
pp. gutjnl-2021-324789
Author(s):  
Nicholas A Kennedy ◽  
Simeng Lin ◽  
James R Goodhand ◽  
Neil Chanchlani ◽  
Benjamin Hamilton ◽  
...  
Keyword(s):  
Single Dose ◽  
Primary Outcome ◽  
Geometric Mean ◽  
Antibody Responses ◽  
Antibody Assay ◽  
Past Infection ◽  
White Ethnicity ◽  
Registration Number ◽  
Inflammatory Bowel ◽  
Prior Infection

ObjectiveDelayed second dose SARS-CoV-2 vaccination trades maximal effectiveness for a lower level of immunity across more of the population. We investigated whether patients with inflammatory bowel disease treated with infliximab have attenuated serological responses to a single dose of a SARS-CoV-2 vaccine.DesignAntibody responses and seroconversion rates in infliximab-treated patients (n=865) were compared with a cohort treated with vedolizumab (n=428), a gut-selective anti-integrin α4β7 monoclonal antibody. Our primary outcome was anti-SARS-CoV-2 spike (S) antibody concentrations, measured using the Elecsys anti-SARS-CoV-2 spike (S) antibody assay 3–10 weeks after vaccination, in patients without evidence of prior infection. Secondary outcomes were seroconversion rates (defined by a cut-off of 15 U/mL), and antibody responses following past infection or a second dose of the BNT162b2 vaccine.ResultsGeometric mean (SD) anti-SARS-CoV-2 antibody concentrations were lower in patients treated with infliximab than vedolizumab, following BNT162b2 (6.0 U/mL (5.9) vs 28.8 U/mL (5.4) p<0.0001) and ChAdOx1 nCoV-19 (4.7 U/mL (4.9)) vs 13.8 U/mL (5.9) p<0.0001) vaccines. In our multivariable models, antibody concentrations were lower in infliximab-treated compared with vedolizumab-treated patients who received the BNT162b2 (fold change (FC) 0.29 (95% CI 0.21 to 0.40), p<0.0001) and ChAdOx1 nCoV-19 (FC 0.39 (95% CI 0.30 to 0.51), p<0.0001) vaccines. In both models, age ≥60 years, immunomodulator use, Crohn’s disease and smoking were associated with lower, while non-white ethnicity was associated with higher, anti-SARS-CoV-2 antibody concentrations. Seroconversion rates after a single dose of either vaccine were higher in patients with prior SARS-CoV-2 infection and after two doses of BNT162b2 vaccine.ConclusionInfliximab is associated with attenuated immunogenicity to a single dose of the BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 vaccines. Vaccination after SARS-CoV-2 infection, or a second dose of vaccine, led to seroconversion in most patients. Delayed second dosing should be avoided in patients treated with infliximab.Trial registration numberISRCTN45176516.

Experimental Schistosoma bovis infection in goats. Circulating antigen and antibody responses to egg and adult worm antigens during infection and following treatment with praziquantel

Parasitology ◽  
1996 ◽  
Vol 113 (4) ◽  
pp. 367-375 ◽  
Author(s):  
M. V. Johansen ◽  
Y. Fillié ◽  
J. Monrad ◽  
N. Ø. Christensen ◽  
A. Deelder
Keyword(s):  
Adult Worm ◽  
Specific Antibody ◽  
Post Treatment ◽  
Antibody Responses ◽  
Antibody Detection ◽  
Faecal Samples ◽  
Schistosoma Bovis ◽  
Worm Recovery ◽  
Circulating Antigen ◽  
Positive Correlations

SUMMARYCirculating antigen levels and antibody responses in Schistosoma bovis-infected West African Dwarf goats were evaluated during infection and following treatment with praziquantel (60 mg/kg) 13 weeks post-infection. One day, 1 week and 4 weeks post-treatment, subgroups of goats were sacrificed and perfused for worm recovery. For comparison, parasite-free control animals were included. Blood and faecal samples were collected biweekly. Two gut-associated schistosome antigens, circulating cathodic and circulating anodic antigen (CCA and CAA) and 3 specific antibody responses (total Ig, IgG and IgM) were measured. For specific antibody detection, crude S. bovis adult worm and egg homogenates were used. The level of CCA in the infected groups was significantly elevated from the time of onset of egg excretion onwards. However, following treatment, the CCA litres dropped to control levels within 1 week post-treatment. Strong positive correlations were found between CCA levels and worm counts and faecal egg counts during peak egg excretion. The correlations of CAA and specific antibody litres to egg and worm counts were poor. The antibody responses were all significantly elevated in the infected goats during patency, but only marginally affected by the treatment. Hence, CCA proved to be superior by correlating strongly to the level of infection and by being a sensitive indicator of the effect of treatment.

Lost in post-translational modification—Dengue virus writes its own sequel

2021 ◽  
Vol 6 (61) ◽  
pp. eabk1555
Author(s):  
Soumya S. Yandamuri ◽  
Kevin C. O’Connor
Keyword(s):  
Virus Infection ◽  
Dengue Virus ◽  
Severe Disease ◽  
Post Translational Modification ◽  
Dengue Virus Infection ◽  
Elevated Frequency ◽  
Prior Infection

Elevated frequency of afucosylated IgG1 antibodies during dengue virus infection is associated with prior infection and predicts severe disease.

scholarly journals Clinical features and outcome of Covid-19 in individuals without Comorbidities. Do children have the advantage?

2021 ◽  
Vol 8 (2) ◽  
pp. 88-93
Author(s):  
Dr. Abhishek Kumar ◽  
◽  
Dr. Nilu Kumari ◽  
Dr. Ranjeet Kumar Singh ◽  
Dr. Alok Kumar ◽  
...  
Keyword(s):  
Severe Disease ◽  
Age Groups ◽  
Asymptomatic Infection ◽  
Healthy Individuals ◽  
Adult Group ◽  
Middle Aged ◽  
History Of ◽  
Adults And Children ◽  
The Mean ◽  
Respiratory Complaints

Objective: Information regarding clinical characteristics and the natural course of COVID-19amongst individuals without comorbidities is scarce. We therefore conducted a retrospectiveobservational study to decipher the disease profile in two different age groups, middle-aged (40-59years) and children (up to 12 years). Method: Study was conducted by reviewing the medicalrecords of all patients in the desired age groups and excluding all those with preexisting illness(called comorbidities). Result: A total of 154 and 27 patients were enrolled and studied in themiddle-aged adults and children group respectively. Males dominated in both groups with a sex ratioof 2.9 in adults and 1.7 in children. Most of the children (92.5%) had a history of exposure from aninfected family member, while in the adult group history of contact was present in 71.4% ofpatients.62.9% of children had an asymptomatic infection which was significantly higher than 22.8%in adults. Cough and fever were the most common symptoms in both age groups, but adults weremore likely to have respiratory complaints when compared with children.11 (7.1%) patients in theadult group had severe disease while in the children group none had severe disease. Similarly in theadult group 11 patients required ICU admission, but none in the children group. The mean durationof RTPCR positivity was similar in both groups. There was 1 (0.6%) expiry in the adult groupwhereas none in children. Conclusion: Healthy individuals in both middle-aged and children grouptend to have milder disease and both harbour the virus for the almost same duration but adults aremore symptomatic in comparison to children and hence children are more likely to be potentialasymptomatic carrier and transmitter of infection.

scholarly journals Can we predict antibody responses in SARS-CoV-2? A cohort analysis

2021 ◽  
Author(s):  
Mary Gaeddert ◽  
Philip Kitchen ◽  
Tobias Broger ◽  
Stefan Weber ◽  
Ralf Bartenschlager ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Severe Disease ◽  
Cohort Analysis ◽  
Antibody Responses ◽  
High Antibody ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Median Increase ◽  
Antibody Titers

AbstractBackgroundAfter infection with severe acute respiratory syndrome coronavirus (SARS-CoV-2), Immunoglobulin G (IgG) antibodies and virus-specific neutralizing antibodies (nAbs) develop. This study describes antibody responses in a cohort of recovered COVID-19 patients to identify predictors.MethodsWe recruited patients with confirmed SARS-CoV-2 infection from Heidelberg, Germany. Blood samples were collected three weeks after COVID-19 symptoms ended. Participants with high antibody titers were invited for follow-up visits. IgG titers were measured by the Euroimmun Assay, and nAbs titers in a SARS-CoV-2 infection-based assay.Results281 participants were enrolled between April and August 2020 with IgG testing, 145 (51.6%) had nAbs, and 35 (12.5%) had follow-up. The median IgG optical density (OD) ratio was 3.1 (Interquartile range (IQR) 1.6-5.1), and 24.1% (35/145) had a nAb titer>1:80. Higher IgG titers were associated with increased age and more severe disease, and higher nAbs were associated with male gender and CT-value of 25-30 on RT-PCR at diagnosis. The median IgG OD ratio on follow-up was 3.7 (IQR 2.9-5.9), a median increase of 0.5 (IQR −0.3-1.7). Six participants with follow-up nAbs all had titers ≤ 1:80.ConclusionsWhile age and disease severity were correlated with IgG responses, predictive factors for nAbs in convalescent patients remain unclear.

Improved diagnosis of viable parenchymal neurocysticercosis by combining antibody banding patterns on enzyme-linked immunoelectrotransfer blot (EITB) with antigen ELISA assay

2021 ◽  
Author(s):  
Gianfranco Arroyo ◽  
Javier A. Bustos ◽  
Andres G. Lescano ◽  
Isidro Gonzales ◽  
Herbert Saavedra ◽  
...  
Keyword(s):  
Latent Class ◽  
False Negative ◽  
Antibody Detection ◽  
Elisa Assay ◽  
True Positive ◽  
Banding Patterns ◽  
Exact Test ◽  
Antigen Elisa ◽  
Class 1 ◽  
Rule Out

The diagnosis of NCC depends on neuroimaging and serological confirmation. While antibody detection by enzyme-linked immunoelectrotransfer blot (EITB) fails to predict viable NCC, EITB banding patterns provide information about the host’s infection course. Adding antigen ELISA results on EITB banding patterns may improve their ability to predict or rule out of viable NCC. We assessed whether combining EITB banding patterns with Ag-ELISA improves discrimination of viable infection in imaging-confirmed parenchymal NCC. EITB banding patterns were grouped into classes using latent class analysis. True-positive and false-negative Ag-ELISA results in each class were compared using Fisher’s exact test. Four classes were identified: 1 (EITB-negative or positive to GP50 alone [GP50 antigen family]), 2 (positive to GP42-39 and GP24 [T24/42 family], with or without GP50), 3 and 4 (positive to GP50, GP42-39 and GP24, and reacting to bands in the 8-kDa family). Most cases in classes 3 and 4 had viable NCC (82% and 88%) compared to classes 2 and 1 (53% and 5%). Adding positive Ag-ELISA results to class 2 predicted all viable NCC cases (22/22 [100%]), whereas 11/40 patients (27.5%) Ag-ELISA negative had viable NCC ( P < 0.001). Only 1/4 patients (25%) Ag-ELISA positive in class 1 had viable NCC, whereas 1/36 patients (2.8%) Ag-ELISA negative had viable NCC ( P = 0.192). In classes 3 and 4, adding Ag-ELISA was not contributory. Combining Ag-ELISA with EITB banding patterns improves discrimination of viable from non-viable NCC, particularly for class-2 responses. Together, these complement neuroimaging more appropriately for the diagnosis of viable NCC.

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