scholarly journals Serum IgG anti-SARS-CoV-2 Binding Antibody Level Is Strongly Associated With IgA and Functional Antibody Levels in Adults Infected With SARS-CoV-2

2021 ◽  
Vol 12 ◽  
Author(s):  
Xunyan Ye ◽  
Laura S. Angelo ◽  
Erin G. Nicholson ◽  
Obinna P. Iwuchukwu ◽  
Wanderson Cabral de Rezende ◽  
...  
Keyword(s):  
Antibody Level ◽  
Predictive Value ◽  
Neutralizing Antibody ◽  
Full Length ◽  
Serum Dilution ◽  
S Protein ◽  
Demographic Groups ◽  
Binding Antibody ◽  
Functional Antibodies ◽  
Antibody Levels

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in December 2019 in Wuhan, China, and then rapidly spread causing an unprecedented pandemic. A robust serological assay is needed to evaluate vaccine candidates and better understand the epidemiology of coronavirus disease (COVID-19).MethodsWe used the full-length spike (S) protein of SARS-CoV-2 for the development of qualitative and quantitative IgG and IgA anti-S enzyme linked immunosorbent assays (ELISA). A total of 320 sera used for assay development were comprised of pandemic sera from SARS-CoV-2 infected adults (n=51) and pre-pandemic sera (n=269) including sera from endemic human coronavirus infected adults. Reverse cumulative curves and diagnostic test statistics were evaluated to define the optimal serum dilution and OD cutoff value for IgG anti-S and IgA anti-S ELISAs. The IgG and IgA anti-S, and three functional antibodies (ACE-2 receptor blocking antibody, lentipseudovirus-S neutralizing antibody, and SARS-CoV-2 neutralizing antibody) were measured using additional SARS-CoV-2 PCR positive sera (n=76) and surveillance sera (n=25). Lastly, the IgG and IgA anti-S levels were compared in different demographic groups.ResultsThe optimal serum dilution for the qualitative IgG anti-S ELISA was at 1:1024 yielding a 99.6% specificity, 92.2% sensitivity, 92.9% positive predictive value (PPV), and 99.6% negative predictive value (NPV) at a SARS-CoV-2 seroprevalence of 5%. The optimal serum dilution for the qualitative IgA anti-S ELISA was at 1:128 yielding a 98.9% specificity, 76.5% sensitivity, 78.3% PPV, and 98.8% NPV at the same seroprevalence. Significant correlations were demonstrated between the IgG and IgA (r=0.833 for concentrations, r=0.840 for titers) as well as between IgG and three functional antibodies (r=0.811-0.924 for concentrations, r=0.795-0.917 for titers). The IgG and IgA anti-S levels were significantly higher in males than females (p<0.05), and in adults with moderate/severe symptoms than in adults with mild/moderate symptoms (p<0.001).ConclusionWe developed a highly specific and sensitive IgG anti-S ELISA assay to SARS-CoV-2 using full length S protein. The IgG anti-S antibody level was strongly associated with IgA and functional antibody levels in adults with SARS-CoV-2 infection. Gender and disease severity, rather than age, play an important role in antibody levels.

scholarly journals Sex disparities and neutralizing antibody durability to SARS-CoV-2 infection in convalescent individuals

2021 ◽  
Author(s):  
Alena J. Markmann ◽  
Natasa Giallourou ◽  
D. Ryan Bhowmik ◽  
Yixuan J. Hou ◽  
Aaron Lerner ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Human Antibody ◽  
Antibody Titers ◽  
Sex Disparities ◽  
Binding Antibody ◽  
Male Sex ◽  
Antibody Levels ◽  
First Time

AbstractThe coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome-related coronavirus-2 (SARS-CoV-2) has now caused over 2 million deaths worldwide and continues to expand. Currently, much is unknown about functionally neutralizing human antibody responses and durability to SARS-CoV-2. Using convalescent sera collected from 101 COVID-19 recovered individuals 21-212 days after symptom onset with forty-eight additional longitudinal samples, we measured functionality and durability of serum antibodies. We also evaluated associations between individual demographic and clinical parameters with functional neutralizing antibody responses to COVID-19. We found robust antibody durability out to six months, as well as significant positive associations with the magnitude of the neutralizing antibody response and male sex. We also show that SARS-CoV-2 convalescent neutralizing antibodies are higher in individuals with cardio-metabolic comorbidities.SignificanceIn this study we found that neutralizing antibody responses in COVID-19 convalescent individuals vary in magnitude but are durable and correlate well with RBD Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex. We also show for the first time, that higher convalescent antibody titers in male donors are associated with increased age and symptom grade. Furthermore, cardio-metabolic co-morbidities are associated with higher antibody titers independently of sex. Here, we present an in-depth evaluation of serologic, demographic, and clinical correlates of functional antibody responses and durability to SARS-CoV-2.

Serological testing for COVID-19

2021 ◽  
Vol 8 (2) ◽  
pp. 35-39
Author(s):  
Attapon Cheepsattayakorn ◽  
Ruangrong Cheepsattayakorn
Keyword(s):  
Polymerase Chain Reaction ◽  
Reverse Transcriptase ◽  
Neutralizing Antibody ◽  
Bibliographic Databases ◽  
Chain Reaction ◽  
Igg Antibody ◽  
S Protein ◽  
Specimen Collection ◽  
Polymerase Chain ◽  
Antibody Levels

The objectives of this study are to identify the rapid, appropriate, screening, definite and novel methods of diagnosis of SARS-CoV-2 (COVID-19) infection, including SARS-CoV-2 (COVID-19) variants among various degree of COVID-19 severity for rapid prevention and control of SARS-CoV-2 (COVID-19) transmission. Methods of The Study: A comprehensive search was carried out in mainstream bibliographic databases or Medical Subject Headings, including ScienDirect, PubMed, Scopus, and ISI Web of Science. The search was applied to the articles that were published between 1971 and early March 2021. Results: With strict literature search and screening processes, it yielded 40 articles from 78 articles of initial literature database. Characteristically, after infection, antibodies are detected in the blood of individuals, particularly individuals with few or mild symptoms. In patients with varying symptoms of COVID-19 and negative results of reverse-transcriptase-polymerase-chain reaction (RT-PCR) tests, the testing has a significantly clinical role when nasopharyngeal swabs are taken more than 5 days after symptom onset. The Royal College of Pathologists (RCPath) developed seven principles for production of a COVID-19 testing strategy. Testing being carried out for a purpose is one of these RCPath’s principles. Nevertheless, denial of requesting SARS-CoV-2 (COVID-19) antibody tests for reassurance should be cautioned. With a lower antibody levels, whether the protective immunity will be sustained is questionable. Several immune-based assays were developed against different SARS-CoV-2 (COVID-19) viral proteins as the followings: 1) Entire Spike (S) protein, IgG antibody from patient serum can cross-react with SARS-CoV and MERS-CoV, 2) S1 subunit of Spike (S) protein, IgA, IgG antibodies from patient serum can cross-react with SARS-CoV only, 3) Receptor-binding domain (RBD), IgG antibody from patient serum can cross-react with SARS-CoV only, and 4) Nucleocapsid (N), IgG antibody from patient serum can cross-react with SARS-CoV only. Long et al demonstrated in their study that IgG antibody and neutralizing antibody levels initiate decreasing within 2-3 months after infection in the majority of persons with recovery from SARS-CoV-2 (COVID-19) infection. An analytical study of the dynamics of neutralizing antibody titers demonstrated reduced neutralizing antibodies around 6-7 weeks after illness onset. In conclusion, the nucleic acid amplification tests may be poorly timed specimen collection, poor-quality specimen collection, long wait times for generating the results, and requirement of trained laboratory technicians. Serological data greatly supplement the laboratory results from the quantitative reverse-transcriptase-polymerase-chain reaction (qRT-PCR), the design of virus elimination programs (seroepidemiology), discovery of the monoclonal antibodies, and development of SARS-CoV-2 (COVID-19) vaccines.

scholarly journals Durability of antibody responses elicited by a single dose of Ad26.COV2.S and substantial increase following late boosting

2021 ◽  
Author(s):  
Jerald Sadoff ◽  
Mathieu Le Gars ◽  
Vicky Cardenas ◽  
Georgi Shukarev ◽  
Nathalie Vaissiere ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Single Dose ◽  
Booster Dose ◽  
Age Groups ◽  
Neutralizing Antibody ◽  
Primary Vaccination ◽  
Antibody Responses ◽  
Binding Antibody ◽  
Antibody Levels ◽  
The Impact

AbstractBackgroundWe evaluated the durability of SARS-CoV-2 antibody levels elicited by the single dose Janssen COVID-19 vaccine, Ad26.COV2.S, and the impact on antibody responses of boosting with Ad26.COV2.S after 6 months in clinical trial participants.MethodsSpike-binding antibody and SARS-CoV-2 neutralizing antibody levels elicited by a single-dose Ad26.COV2.S (5×1010 viral particles [vp]) primary regimen and booster doses (5×1010 vp and 1.25×1010 vp) were assessed by ELISA and wild-type VNA in sera from participants in a Phase 1/2a clinical trial (Cohort 1a, 18–55 years old, N=25; Cohort 2a, 18–55 years old boosted at 6 months, N=17; Cohort 3, ≥65 years old, N=22) and a Phase 2 clinical trial (18–55 and ≥65-year old participants boosted at 6 months, total N=73). Neutralizing antibody levels were determined approximately 8 months after the primary vaccination in participants aged 18–55 years and approximately 9 months in participants aged ≥65 years. Binding antibody levels were evaluated 6 months after primary vaccination and 7- and 28-days after booster doses in both age groups.ResultsA single dose of Ad26.COV2.S elicited neutralizing antibodies that remained largely stable for approximately 8–9 months and binding antibodies that remained stable for at least 6 months irrespective of age group. A 5×1010 vp booster dose at 6 months post prime vaccination in 18–55-year-old adults elicited a steep and robust 9-fold increase at Day 7 post boost compared to Day 29 levels following the initial immunization. A lower booster dose of 1.25×1010 vp at 6 months in adults 18–55 and ≥65 years of age also elicited a rapid and high increase of 6–7.7 fold at Day 28 post boost compared to Day 29 levels following the initial immunization, with similar magnitude of post-boost responses in both age groups.ConclusionsA single dose of Ad26.COV2.S, which demonstrated protection in a Phase 3 efficacy trial, elicited durable neutralizing and binding antibodies for at least 8 and 6 months, respectively, in adults >18 years of age at levels similar to Day 29 responses. A 5×1010 vp or 1.25×1010 vp booster dose at 6 months elicited rapid and robust increases in spike binding antibody levels. The anamnestic responses after booster immunization imply robust immune memory elicited by single-dose Ad26.COV2.S.

scholarly journals Dichotomy between the humoral and cellular responses elicited by mRNA and adenoviral vector vaccines against SARS-CoV-2

2021 ◽  
Author(s):  
Rahul Ukey ◽  
Natalie Bruiners ◽  
Hridesh Mishra ◽  
Pankaj K. Mishra ◽  
Deborah McCloskey ◽  
...  
Keyword(s):  
Single Dose ◽  
Adenoviral Vector ◽  
Severe Disease ◽  
Neutralizing Antibody ◽  
Cellular Responses ◽  
Real World Data ◽  
Symptomatic Infection ◽  
Cell Responses ◽  
Binding Antibody ◽  
Antibody Levels

AbstractProtection from severe disease and hospitalization by SARS-CoV-2 vaccination has been amply demonstrated by real-world data. However, the rapidly evolving pandemic raises new concerns. One pertains efficacy of adenoviral vector-based vaccines, particularly the single-dose Ad26.COV2.S, relative to mRNA vaccines. We investigated the immunogenicity of Ad26.COV2.S and mRNA vaccines in 33 subjects vaccinated with either vaccine class five months earlier on average. After controlling for time since vaccination, Spike-binding antibody and neutralizing antibody levels were higher in the mRNA-vaccinated subjects, while no significant differences in antigen-specific B cell and T cell responses were observed between the two groups. Thus, a dichotomy exists between humoral and cellular responses elicited by the two vaccine classes. Our results have implications for the need of booster doses in vaccinated subjects and might explain the dichotomy reported between the waning protection from symptomatic infection by SARS-CoV-2 vaccination and its persisting efficacy in preventing hospitalization and death.

scholarly journals Sex Disparities and Neutralizing-Antibody Durability to SARS-CoV-2 Infection in Convalescent Individuals

mSphere ◽  
2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Alena J. Markmann ◽  
Natasa Giallourou ◽  
D. Ryan Bhowmik ◽  
Yixuan J. Hou ◽  
Aaron Lerner ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Neutralizing Antibody ◽  
Binding Domain ◽  
Antibody Responses ◽  
Receptor Binding Domain ◽  
Antibody Titers ◽  
Sex Disparities ◽  
Binding Antibody ◽  
Male Sex ◽  
Antibody Levels

In this study, we found that neutralizing antibody responses in COVID-19-convalescent individuals vary in magnitude but are durable and correlate well with receptor binding domain (RBD) Ig binding antibody levels compared to other SARS-CoV-2 antigen responses. In our cohort, higher neutralizing antibody titers are independently and significantly associated with male sex compared to female sex.

scholarly journals Evaluation of Transplacental Antibody Transfer in SARS-CoV-2-Immunized Pregnant Women

Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 101
Author(s):  
Ching-Ju Shen ◽  
Yi-Chen Fu ◽  
Yen-Pin Lin ◽  
Ching-Fen Shen ◽  
Der-Ji Sun ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Antibody Level ◽  
Neutralizing Antibodies ◽  
Dose Group ◽  
Neutralizing Antibody ◽  
Effective Vaccine ◽  
Igg Antibody ◽  
Maternal Mrna ◽  
The One ◽  
Antibody Levels

Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy could result in adverse perinatal outcome. Clinical data on the assessment of the immune response in vaccinated pregnant women and subsequent transplacental antibody transfer are quite limited. Objective: To assess maternal and neonatal neutralizing antibody levels against both wildtype and Delta (B.1.617.2) variants after maternal mRNA vaccination. Study Design: This cohort study was conducted 29 pregnant women who were vaccinated at least one dose of Moderna (mRNA-1273) vaccine. Both neutralizing antibody (wildtype and Delta variant) and S1 receptor binding domain IgG antibody levels were evaluated in maternal and cord blood on the day of delivery. Results: Superiority of antibody level was significant in fully vaccinated women compared with the one-dose group (maternal sera, median, 97.46%; cord sera, median, 97.37% versus maternal sera, median, 4.01%; cord sera, median, 1.44%). No difference in antibody level was noted in relation to interval of second immunization to delivery in the two-dose group (95.99% in 0–2 weeks, 97.45% in 2–4 weeks, 97.48% in 4–8 weeks, 97.72% in 8–10 weeks). The most pronounced reduction was observed for the Delta variant. The wildtype neutralizing antibody level of full-vaccinated women was not influenced by the pertussis vaccination. Conclusion: The data underscore the importance of full vaccination in pregnancy and support the recommendation of COVID-19 immunization for pregnant women. The lower level of vaccine-induced neutralizing antibodies for the Delta variant indicates insufficient protection for mother and newborn and highlights the need for development of effective vaccine strategies.

scholarly journals Neutralizing Antibodies Responses to SARS-CoV-2 in COVID-19 Inpatients and Convalescent Patients

2020 ◽  
Author(s):  
Xiaoli Wang ◽  
Xianghua Guo ◽  
Qianqian Xin ◽  
Yanhui Chu ◽  
Jing Li ◽  
...  
Keyword(s):  
Individual Differences ◽  
Antibody Level ◽  
Neutralizing Antibodies ◽  
Clinical Characteristics ◽  
Early Stage ◽  
Neutralizing Antibody ◽  
Clinical Classification ◽  
Seropositivity Rate ◽  
Blood Samples ◽  
Antibody Levels

AbstractBackgroundCOVID-19 is a pandemic with no specific antiviral treatments or vaccines. The urgent needs for exploring the neutralizing antibodies from patients with different clinical characteristics are emerging.MethodsA total of 117 blood samples were collected from 70 COVID-19 inpatients and convalescent patients. The presence of neutralizing antibody was determined with a modified cytopathogenic assay based on live SARS-CoV-2. The dynamics of neutralizing antibody levels at different with different clinical characteristics were analyzed.ResultsThe seropositivity rate reached up to 100.0% within 20 days since onset, and remained 100.0% till day 41-53. The total GMT was 1:163.7 (95% CI, 128.5 to 208.6), and the antibody level was highest during day 31-40 since onset, and then decreased slightly. Individual differences in changes of antibody levels were observed among 8 representative convalescent patients. In multivariate GEE analysis, patients at age of 31-60 and 61-84 had a higher antibody level than those at age of 16-30 (β=1.0518, P=0.0152; β=1.3718, P=0.0020). Patients with a worse clinical classification had a higher antibody titer (β=0.4639, P=0.0227).ConclusionsThe neutralizing antibodies were detected even at the early stage of disease, and a significant response showed in convalescent patients. Moreover, changes on antibody levels ware individual specific.

scholarly journals Longitudinal Serological Analysis and Neutralizing Antibody Levels in Coronavirus Disease 2019 Convalescent Patients

2020 ◽  
Author(s):  
Frauke Muecksch ◽  
Helen Wise ◽  
Becky Batchelor ◽  
Maria Squires ◽  
Elizabeth Semple ◽  
...  
Keyword(s):  
Neutralizing Antibody ◽  
Neutralization Titer ◽  
Serological Assay ◽  
Antibody Assays ◽  
Antibody Titers ◽  
Binding Antibody ◽  
Antibody Levels ◽  
Prior Infection ◽  
Commercial Platform

Abstract Background Understanding the longitudinal trajectory of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies is crucial for diagnosis of prior infection and predicting future immunity. Methods We conducted a longitudinal analysis of coronavirus disease 2019 convalescent patients, with neutralizing antibody assays and SARS-CoV-2 serological assay platforms using SARS-CoV-2 spike (S) or nucleocapsid (N) antigens. Results Sensitivities of serological assays in diagnosing prior SARS-CoV-2 infection changed with time. One widely used commercial platform that had an initial sensitivity of >95% declined to 71% at 81–100 days after diagnosis. The trajectories of median binding antibody titers measured over approximately 3–4 months were not dependent on the use of SARS-CoV-2 N or S proteins as antigen. The median neutralization titer decreased by approximately 45% per month. Each serological assay gave quantitative antibody titers that were correlated with SARS-CoV-2 neutralization titers, but S-based serological assay measurements better predicted neutralization potency. Correlation between S-binding and neutralization titers deteriorated with time, and decreases in neutralization titers were not predicted by changes in S-binding antibody titers. Conclusions Different SARS-CoV-2 serological assays are more or less well suited for surveillance versus prediction of serum neutralization potency. Extended follow-up should facilitate the establishment of appropriate serological correlates of protection against SARS-CoV-2 reinfection.

scholarly journals Role of Small Envelope Protein in Sustaining the Intracellular and Extracellular Levels of Hepatitis B Virus Large and Middle Envelope Proteins

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 613
Author(s):  
Jing Zhang ◽  
Yongxiang Wang ◽  
Shuwen Fu ◽  
Quan Yuan ◽  
Qianru Wang ◽  
...  
Keyword(s):  
Envelope Proteins ◽  
Full Length ◽  
M Protein ◽  
Intracellular Level ◽  
S Protein ◽  
L Protein ◽  
M Proteins ◽  
B Virus ◽  
Subviral Particle ◽  
Genotype A

Hepatitis B virus (HBV) expresses co-terminal large (L), middle (M), and small (S) envelope proteins. S protein drives virion and subviral particle secretion, whereas L protein inhibits subviral particle secretion but coordinates virion morphogenesis. We previously found that preventing S protein expression from a subgenomic construct eliminated M protein. The present study further examined impact of S protein on L and M proteins. Mutations were introduced to subgenomic construct of genotype A or 1.1mer replication construct of genotype A or D, and viral proteins were analyzed from transfected Huh7 cells. Mutating S gene ATG to prevent expression of full-length S protein eliminated M protein, reduced intracellular level of L protein despite its blocked secretion, and generated a truncated S protein through translation initiation from a downstream ATG. Truncated S protein was secretion deficient and could inhibit secretion of L, M, S proteins from wild-type constructs. Providing full-length S protein in trans rescued L protein secretion and increased its intracellular level from mutants of lost S gene ATG. Lost core protein expression reduced all the three envelope proteins. In conclusion, full-length S protein could sustain intracellular and extracellular L and M proteins, while truncated S protein could block subviral particle secretion.

scholarly journals Immunization with RBD-P2 and N protects against SARS-CoV-2 in nonhuman primates

2021 ◽  
Vol 7 (22) ◽  
pp. eabg7156
Author(s):  
So-Hee Hong ◽  
Hanseul Oh ◽  
Yong Wook Park ◽  
Hye Won Kwak ◽  
Eun Young Oh ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Nonhuman Primates ◽  
Vaccine Candidate ◽  
Statistical Significance ◽  
Neutralizing Antibody ◽  
Spike Protein ◽  
Vaccine Candidates ◽  
Cell Responses ◽  
Antibody Levels ◽  
Further Development

Since the emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), various vaccines are being developed, with most vaccine candidates focusing on the viral spike protein. Here, we developed a previously unknown subunit vaccine comprising the receptor binding domain (RBD) of the spike protein fused with the tetanus toxoid epitope P2 (RBD-P2) and tested its efficacy in rodents and nonhuman primates (NHPs). We also investigated whether the SARS-CoV-2 nucleocapsid protein (N) could increase vaccine efficacy. Immunization with N and RBD-P2 (RBDP2/N) + alum increased T cell responses in mice and neutralizing antibody levels in rats compared with those obtained using RBD-P2 + alum. Furthermore, in NHPs, RBD-P2/N + alum induced slightly faster SARS-CoV-2 clearance than that induced by RBD-P2 + alum, albeit without statistical significance. Our study supports further development of RBD-P2 as a vaccine candidate against SARS-CoV-2. Also, it provides insights regarding the use of N in protein-based vaccines against SARS-CoV-2.

Sign in / Sign up

Export Citation Format

Share Document