scholarly journals Detection of Nucleocapsid Antibody to SARS-CoV-2 is More Sensitive than Antibody to Spike Protein in COVID-19 Patients

Author(s):  
Peter D. Burbelo ◽  
Francis X. Riedo ◽  
Chihiro Morishima ◽  
Stephen Rawlings ◽  
Davey Smith ◽  
...  

ABSTRACTBackgroundSARS-CoV-2, the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related morbidity and mortality. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response.MethodologyQuantitative measurements of plasma or serum antibodies by luciferase immunoprecipitation assay systems (LIPS) to the nucleocapsid and spike proteins were analyzed in 100 cross-sectional or longitudinal samples from SARS-CoV-2-infected patients. A subset of samples was tested with and without heat inactivation.ResultsFifteen or more days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, while antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from six patients with COVID-19 showed anti-nucleocapsid and spike antibodies appearing between day 8 to day 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2 compared to immunocompetent patients.ConclusionsAntibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples by LIPS is a safe and sensitive method for detecting SARS-CoV-2 antibodies.

2020 ◽  
Vol 222 (2) ◽  
pp. 206-213 ◽  
Author(s):  
Peter D Burbelo ◽  
Francis X Riedo ◽  
Chihiro Morishima ◽  
Stephen Rawlings ◽  
Davey Smith ◽  
...  

Abstract Background Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of coronavirus disease 2019 (COVID-19), is associated with respiratory-related disease and death. Assays to detect virus-specific antibodies are important to understand the prevalence of infection and the course of the immune response. Methods Quantitative measurements of plasma or serum antibodies to the nucleocapsid and spike proteins were analyzed using luciferase immunoprecipitation system assays in 100 cross-sectional or longitudinal samples from patients with SARS-CoV-2 infection. A subset of samples was tested both with and without heat inactivation. Results At >14 days after symptom onset, antibodies against SARS-CoV-2 nucleocapsid protein showed 100% sensitivity and 100% specificity, whereas antibodies to spike protein were detected with 91% sensitivity and 100% specificity. Neither antibody levels nor the rate of seropositivity were significantly reduced by heat inactivation of samples. Analysis of daily samples from 6 patients with COVID-19 showed anti-nucleocapsid and spike protein antibodies appearing between days 8 and 14 after initial symptoms. Immunocompromised patients generally had a delayed antibody response to SARS-CoV-2, compared with immunocompetent patients. Conclusions Antibody to the nucleocapsid protein of SARS-CoV-2 is more sensitive than spike protein antibody for detecting early infection. Analyzing heat-inactivated samples with a luciferase immunoprecipitation system assay is a safe and sensitive method for detecting SARS-CoV-2 antibodies.


2021 ◽  
Vol 7 (22) ◽  
pp. eabg7156
Author(s):  
So-Hee Hong ◽  
Hanseul Oh ◽  
Yong Wook Park ◽  
Hye Won Kwak ◽  
Eun Young Oh ◽  
...  

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.


2017 ◽  
Vol 34 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Claudio Rodríguez-Camejo ◽  
Arturo Puyol ◽  
Laura Fazio ◽  
Analía Rodríguez ◽  
Emilia Villamil ◽  
...  

Background: When feeding preterm infants, donor milk is preferred if the mother’s own milk is unavailable. Pasteurization may have detrimental effects on bioactivity, but more information is needed about its effects on the immunological compounds. Research aim: This work has two main aims: evaluate the antibody profile of colostrum and study the quantitative variations in the antibodies’ level and specific reactivity after undergoing Holder pasteurization. The authors focused on immunoregulatory components of colostrum (antidietary antibodies and TGF-β2) in the neonatal gut. Methods: This is a descriptive cross-sectional study of a convenience sample of 67 donated colostrum samples at different days after delivery, both raw and pasteurized. Antibody profiles were analyzed at different times during breastfeeding, and total and specific antibodies (IgM, IgA, and IgG subclasses) were compared with tetanus toxoid and ovalbumin using enzyme-linked immunosorbent assay. The processing effect on total and specific antibodies, as well as TGF-β2, was evaluated by paired analyses. Results: No variations in immunological compounds were observed throughout the colostrum stage. The TGF-β2, antibodies’ concentrations, and antibodies’ specific reactivity after pasteurization did not vary significantly as days of lactation varied. Changes in antibody levels were dependent on isotype and IgG subclass, and IgG4 showed remarkable resistance to heating. Moreover, the effect of the pasteurization on specific reactivity was antigen dependent. Conclusion: The supply of relevant immunological components is stable throughout the colostrum stage. The effects of pasteurization on antibodies depend on isotype, subclass, and specificity. This information is relevant to improving the immunological quality of colostrum, especially for preterm newborns.


2021 ◽  
Author(s):  
Umar Saeed ◽  
Sara Rizwan Uppal ◽  
Zahra Zahid Piracha ◽  
Aftab Ahmad Khan ◽  
Azhar Rasheed ◽  
...  

Abstract Rapid ramp up of immune responses against SARS-CoV-2 during pandemic enables adequate prevention and treatment for COVID-19. Estimating levels of SARS-CoV-2 spike protein antibodies post vaccination is crucial for designing mass-vaccination strategies. The aim of this study was to evaluate effectiveness of Sputnik V first dose in Pakistan. A cross-sectional study of 2000 participants was conducted for examining Gam-COVID-Vac or Sputnik V first dose effects at 21st days post administration at Islamabad Diagnostic Center, Islamabad, Pakistan. From 100 real-time PCR negative (SARS-CoV-2 RNA) individuals, samples were collected and analyzed for antibodies to the SARS-CoV-2 spike protein using Electro-chemiluminescence immunoassay (ECLIA) (Elecsys # 09289267190 Roche, USA). 85% of the participants showed strong positive results with SARS-CoV-2 spike protein antibodies >1.5 AU/ml. The individuals with antibody titer >250 AU/ml were 34.9%. Among those with antibody levels >250 AU/ml 52% had previous history of COVID-19 infection. While participants with >100 AU/ml of antibodies were 12.7%. However 9.5% showed antibody titer of >25 AU/ml. 27% of participants had antibody titers of >1.5-2.5 AU/ml. While antibody titers of <1.5 AU/ml were observed among 15.9% of participants. Majority of the individuals represented significantly high antibody titers against SARS-CoV-2 even before second booster dose of Ad5 based Sputnik V vaccine. Continuous monitoring of antibody levels among COVID-19 vaccinated populations are deemed to assess humoral immunity status against SARS-CoV-2 infections.


2021 ◽  
Author(s):  
Frauke Muecksch ◽  
Helen Wise ◽  
Kate Templeton ◽  
Becky Batchelor ◽  
Maria Squires ◽  
...  

Background Serological assays are being deployed to monitor antibody responses in SARS-CoV-2 convalescents and vaccine recipients. There is a need to determine whether such assays can predict immunity, as antibody levels wane and viral variants emerge. Methods We measured antibodies in a cohort of SARS-CoV-2 infected patients using several high-throughput serological tests and functional neutralization assays. The effects of time and spike protein sequence variation on the performance and predictive value of the various assays was assessed. Findings Neutralizing antibody titers decreased over the first few months post-infection but stabilized thereafter, at about 30% of the level observed shortly after infection. Serological assays commonly used to measure antibodies against SARS-CoV-2 displayed a range of sensitivities that declined to varying extents over time. Quantitative measurements generated by serological assays based on the spike protein were better at predicting neutralizing antibody titers than assays based on nucleocapsid, but performance was variable and manufacturer positivity thresholds were not able to predict the presence or absence of detectable neutralizing activity. Even though there was some deterioration in correlation between serological measurements and functional neutralization activity, some assays maintained an ability to predict neutralizing titers, even against variants of concern. Interpretation The ability of high throughput serological assays to predict neutralizing antibody titers is likely crucial for evaluation of immunity at the population scale. These data will facilitate the selection of the most suitable assays as surrogates of functional neutralizing activity and suggest that such measurements may have utility in clinical practice.


2021 ◽  
Author(s):  
Thomas Akerlund ◽  
Katherina Zakikhany ◽  
Charlotta Lofstrom ◽  
Evelina Lindmark ◽  
Henrik Kallberg ◽  
...  

More knowledge regarding persistence of antibody response to SARS-CoV-2 infections in the general population with mild symptoms is needed. We measured and compared levels of SARS-CoV-2 spike- and nucleocapsid-specific IgG-antibodies in serum samples from 145 laboratory-confirmed COVID-19 cases and 324 non-cases. The IgG-antibody levels against the spike protein in cases were stable over the time-period studied (14 to 256 days), while antibody levels against the nucleocapsid protein decreased over time.


2021 ◽  
Vol 42 (1) ◽  
pp. 69-75
Author(s):  
Shivani Singh ◽  
Ashok Kumar Ahirwar ◽  
Priyanka Asia ◽  
Niranjan Gopal ◽  
Kirti Kaim ◽  
...  

Abstract COVID-19 caused by SARS CoV2 (The novel corona virus) has already taken lives of many people across the globe even more than anyone could have imagined. This outbreak occurred in China and since then it is expanding its devastating effects by leaps and bounds. Initially it appeared to be an outbreak of pneumonia but soon it was found to be much more than that and the infectivity was found to be very high. This is the reason that it has taken whole globe in its trap and become a pandemic in such a short span of time. Death is occurring because it is a new virus and human body has no specific antibodies for it. Presently there is no approved vaccine so everyone is susceptible but people with co-morbidities appear to be in more risk and the best way for protection is social distancing and increasing one’s natural immunity by taking healthy diet and exercise. When a person is infected the clinical presentation ranges from asymptomatic to severe ARDS, sudden onset of anosmia, headache, cough may be the initial symptoms. This review is focused on immunopathology and effect of COVID-19 on neurological disorders and also the neurological manifestations and the treatment.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Teresa Aydillo ◽  
Alexander Rombauts ◽  
Daniel Stadlbauer ◽  
Sadaf Aslam ◽  
Gabriela Abelenda-Alonso ◽  
...  

AbstractIn addition to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), humans are also susceptible to six other coronaviruses, for which consecutive exposures to antigenically related and divergent seasonal coronaviruses are frequent. Despite the prevalence of COVID-19 pandemic and ongoing research, the nature of the antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Here we longitudinally profile the early humoral immune response against SARS-CoV-2 in hospitalized coronavirus disease 2019 (COVID-19) patients and quantify levels of pre-existing immunity to OC43, HKU1 and 229E seasonal coronaviruses, and find a strong back-boosting effect to conserved but not variable regions of OC43 and HKU1 betacoronaviruses spike protein. However, such antibody memory boost to human coronaviruses negatively correlates with the induction of IgG and IgM against SARS-CoV-2 spike and nucleocapsid protein. Our findings thus provide evidence of immunological imprinting by previous seasonal coronavirus infections that can potentially modulate the antibody profile to SARS-CoV-2 infection.


2020 ◽  
Vol 148 ◽  
Author(s):  
T. C. Abreu ◽  
H. Boshuizen ◽  
L. Mollema ◽  
G. A. M. Berbers ◽  
H. Korthals Altes

Abstract Vaccination has reduced the disease burden of vaccine-preventable diseases. However, the extent to which seasonal cycles of immunity could influence vaccine-induced immunity is not well understood. A national cross-sectional serosurveillance study performed in the Netherlands (Pienter-2) yielded data to investigate whether season of vaccination was associated with antibody responses induced by DT-IPV (diphtheria, tetanus and poliomyelitis), MMR (measles, mumps and rubella) and meningococcus C (MenC) vaccines in children. In total, 434 children met the inclusion criteria to study DT-IPV immunity, 811 for MMR and 311 for MenC. Differences in log(antibody levels) by season of vaccination were investigated with linear multivariable regression analyses. Seroconversion rates varied according to season of vaccination for rubella (90% of autumn-vaccinated children vs. 99% of winter-vaccinated had concentrations above cut-off levels). Summer-vaccinated boys showed a slower decline of tetanus antibodies (6% per month), in comparison with winter-vaccinated boys. In conclusion, season of vaccination showed little association with immunological protection. However, a number of associations were seen with a P-value of about 0.03; and adding data from a just-completed nationwide serological study might add more power to the current study. Further immunological and longitudinal investigations could help understand the mechanisms of seasonal influence in vaccine-induced responses.


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