scholarly journals DISAPPEARANCE OF ANTIBODIES IN COVID-19 MYTHS ORREALITY

2021 ◽  
Vol 71 (Suppl-3) ◽  
pp. S530-33
Author(s):  
Maqbool Raza ◽  
Muhammed Ali Raza ◽  
De Emmal Asjad Cheema ◽  
Maham Asjad Cheema ◽  
Atif Rafique ◽  
...  
Keyword(s):  
Antibody Level ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Cross Sectional Study ◽  
Assay Method ◽  
Military Hospital ◽  
Serum Samples ◽  
Cross Sectional ◽  
Severity Of The Disease

Objective: To explore the disappearance of neutralizing antibodies from patients, their myths, and facts. Study Design: Cross-sectional study. Place and Duration of Study: Combined Military Hospital Multan Pakistan, from Jul 2021 to Aug 2021. Methodology: A total of 100 blood samples were collected from 100 COVID-19 patients. These 100 patients were followed up for a period of 3 months. Antibodies were determined with the modified neutralization assay method and enzyme-linked immuno-sorbent assay (ELISA). Results: The antibody level by NA and ELISA peaked on days 30-35 then decreased slightly. In multivariate analysis, patients aged 25-35, 36-56, and 57-84 years had a higher neutralizing antibody level than those aged 10-21 years. The patient with the worst clinical manifestation had a higher neutralizing antibody titer. In serum samples, IgG was undetectable at 18.3% and 11% and the geographical mean reciprocal titers dropped from 244 at 3-month period and neutralizing antibodies, the geographical mean reciprocal titers dropped from 874 at 3 months. Conclusion: All COVID-19 patients were seropositive and significantly neutralizing antibody response. Neutralizing antibody levels depend on the time after the onset of symptoms, age, and severity of the disease.

scholarly journals IMMUNOGENICITY AND SAFETY OF INACTIVATED SARS-COV-2 VACCINE (VERO CELL), BBIBP-CORV (SINOPHARM); AN OBSERVATIONAL STUDY FROM PAKISTAN

2021 ◽  
Vol 71 (6) ◽  
pp. 2024-28
Author(s):  
Muhammad Farooq ◽  
Muhammad Fayyaz Malik ◽  
Ashfaq Hussain ◽  
Majid Latif ◽  
Muhammad Usman Rathore ◽  
...  
Keyword(s):  
Vero Cell ◽  
Neutralizing Antibodies ◽  
Adverse Reactions ◽  
Seroconversion Rate ◽  
Vaccine Dose ◽  
Neutralizing Antibody ◽  
Cross Sectional Study ◽  
Military Hospital ◽  
Cross Sectional ◽  
Antibody Titers

Objective: To ascertain the immunogenicity and short-term safety of inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBPCorV (Sinopharm) in our setup. Study Design: Cross-sectional study. Place and Duration of Study: Combined Military Hospital Sialkot Pakistan, from Feb to Apr 2021. Methodology: A total of 227 health care workers (HCWs) between 18 to 59 years of age were included in the study. Two doses of Inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBP-CorV were administered to all individuals 21 days apart and they were monitored for any vaccine-related adverse reactions for 7 days after each dose. Neutralizing antibodies (NAbs) in study subjects were detected in three samples i.e. before 1st dose of vaccine, 21 days after 1st dose and 14 days after 2nd dose by Elecsys Anti- SARS-CoV-2 S (Roche Diagnostics). Results: Mean age of individuals in the study was 36.70 ± 18.08 years and most individuals were in the 31-45 years age group. Fatigue and drowsiness were the most common adverse effects experienced by study subjects after 1st and 2nd dose of the vaccine followed by malaise and headache. Only 42 (39%) individuals developed positive neutralizing antibody titers in a sample taken 21 days after 1st dose while all individuals except one (99%) developed positive neutralizing antibody titers in a sample taken 2 weeks after 2nd vaccine dose. Conclusion: Inactivated SARS-CoV-2 Vaccine (Vero Cell), BBIBP-CorV is safe and well-tolerated with very few adverse reactions. Immunogenicity was well achieved as the seroconversion rate was 99% two weeks after 2nd dose of the vaccine.

scholarly journals Presence of Antibodies against Sindbis Virus in the Israeli Population: A Nationwide Cross-Sectional Study

Viruses ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 542
Author(s):  
Ravit Koren ◽  
Ravit Bassal ◽  
Tamy Shohat ◽  
Daniel Cohen ◽  
Orna Mor ◽  
...  
Keyword(s):  
Sindbis Virus ◽  
Metropolitan Areas ◽  
Multivariable Analysis ◽  
Neutralization Assay ◽  
Cross Sectional Study ◽  
Older Age ◽  
Igg Antibodies ◽  
Serum Samples ◽  
Cross Sectional ◽  
Israeli Population

Sindbis virus (SINV) is a mosquito-borne alphavirus circulating globally. SINV outbreaks have been mainly reported in North-European countries. In Israel, SINV was detected in 6.3% of mosquito pools; however, SINV infection in humans has rarely been diagnosed. A serologic survey to detect SINV IgG antibodies was conducted to evaluate the seroprevalence of SINV in the Israeli population. In total, 3145 serum samples collected in 2011–2014, representing all age and population groups in Israel, were assessed using an indirect ELISA assay, and a neutralization assay was performed on all ELISA-positive samples. The prevalence rates of SINV IgG antibodies were calculated. Logistic regressions models were applied to assess the association between demographic characteristics and SINV seropositivity. Overall, 113 (3.6%) and 59 (1.9%) samples were positive for ELISA and neutralization SINV IgG, respectively. Multivariable analysis demonstrated that SINV seropositivity was significantly associated with older age and residence outside metropolitan areas. These results demonstrate that, despite no outbreaks or clinical presentation, SINV infects the human population in Israel. Seropositivity is countrywide, more frequent in people of older age, and less diffuse in Israel’s metropolitan areas. Seroprevalence studies from other countries will add to our understanding of the global burden of SINV and the risk for potential SINV outbreaks.

scholarly journals The Dynamics of Neutralizing Antibody Level in One Year After SARS-CoV-2 Infection

2021 ◽  
Author(s):  
Dan Liang ◽  
Guanting Zhang ◽  
Mingxing Huang ◽  
Wenshan Hong ◽  
An'an Li ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Antibody Level ◽  
Diagnostic Tests ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Blood Samples ◽  
Immune Ability ◽  
One Year

Abstract Background: A lot of recent researches have focused on the duration of the nature immunity elicited by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. An improved understanding of the immunity offered by the antibodies developed against SARS-CoV-2 in recovered patients is critical for the development of diagnostic tests and vaccines. Methods: We enrolled 114 donors, which providing blood samples after discharge for half a year and one year. Neutralizing antibodies (NAbs) were tested using a micro-neutralization assay. Results: In two tests, 82 of 114 recovered patients completed the first test half a year after discharge and NAbs remained detectable in the vast majority of patients (75/82, 91.46%). In the comparison of the two intervals, 50% (27/54) of individuals had increased NAbs titers. when 31.48% (17/54) of patients remained unchanged. Conclusion: Our results suggest that immune ability is acquired in most individuals infected with SARS-CoV-2 and is sustained in a majority of patients for up to a year after recovery.

scholarly journals Neutralizing Antibody Responses to Severe Acute Respiratory Syndrome Coronavirus 2 in Coronavirus Disease 2019 Inpatients and Convalescent Patients

2020 ◽  
Vol 71 (10) ◽  
pp. 2688-2694 ◽  
Author(s):  
Xiaoli Wang ◽  
Xianghua Guo ◽  
Qianqian Xin ◽  
Yang Pan ◽  
Yaling Hu ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Antibody Level ◽  
Neutralizing Antibodies ◽  
Clinical Characteristics ◽  
Early Stage ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Estimating Equation ◽  
Neutralization Assay ◽  
Enzyme Linked Immunosorbent Assay

Abstract Background Coronavirus disease 2019 (COVID-19) is a pandemic with no specific antiviral treatments or vaccines. There is an urgent need for exploring the neutralizing antibodies from patients with different clinical characteristics. Methods A total of 117 blood samples were collected from 70 COVID-19 inpatients and convalescent patients. Antibodies were determined with a modified cytopathogenic neutralization assay (NA) based on live severe acute respiratory syndrome coronavirus 2 and enzyme-linked immunosorbent assay (ELISA). The dynamics of neutralizing antibody levels at different time points with different clinical characteristics were analyzed. Results The seropositivity rate reached up to 100.0% within 20 days since onset, and remained 100.0% till days 41–53. The total geometric mean titer was 1:163.7 (95% confidence interval [CI], 128.5–208.6) by NA and 1:12 441.7 (95% CI, 9754.5–15 869.2) by ELISA. The antibody level by NA and ELISA peaked on days 31–40 since onset, and then decreased slightly. In multivariate generalized estimating equation analysis, patients aged 31–45, 46–60, and 61–84 years had a higher neutralizing antibody level than those aged 16–30 years (β = 1.0470, P = .0125; β = 1.0613, P = .0307; β = 1.3713, P = .0020). Patients with a worse clinical classification had a higher neutralizing antibody titer (β = 0.4639, P = .0227). Conclusions The neutralizing antibodies were detected even at the early stage of disease, and a significant response was shown in convalescent patients.

scholarly journals Serological Screening for Antibodies against SARS-CoV-2 in Dutch Shelter Cats

Viruses ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1634
Author(s):  
W. J. R. van der Leij ◽  
Els M. Broens ◽  
Jan Willem Hesselink ◽  
Nancy Schuurman ◽  
Johannes C. M. Vernooij ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Large Scale ◽  
Companion Animals ◽  
Significant Risk ◽  
Cross Sectional Study ◽  
Serum Samples ◽  
Serological Screening ◽  
Cross Sectional ◽  
Animal Shelters ◽  
Second Wave

The COVID-19 pandemic raised concerns that companion animals might be infected with, and could become a reservoir of, SARS-CoV-2. As cats are popular pets and susceptible to Coronavirus, we investigated the seroprevalence of SARS-CoV-2 antibodies in shelter cats housed in Dutch animal shelters during the COVID-19 pandemic. In this large-scale cross-sectional study, serum samples of shelter cats were collected during the second wave of human COVID-19 infections in The Netherlands. Seroprevalence was determined by using an indirect protein-based ELISA validated for cats, and a Virus Neutralization Test (VNT) as confirmation. To screen for feline SARS-CoV-2 shedding, oropharyngeal and rectal swabs of cats positive for ELISA and/or VNT were analyzed using PCR tests. In 28 Dutch animal shelters, 240 shelter cats were convenience sampled. Two of these cats (0.8%; CI 95%: 0.1–3.0%) were seropositive, as evidenced by the presence of SARS-CoV-2 neutralizing antibodies. The seropositive animals tested PCR negative for SARS-CoV-2. Based on the results of this study, it is unlikely that shelter cats could be a reservoir of SARS-CoV-2 or pose a (significant) risk to public health.

scholarly journals First seroepidemiological investigation of human enterovirus 71 in Iran

2021 ◽  
Author(s):  
Mahsa Javadi ◽  
Ahmad Nejati ◽  
Maryam Yousefi ◽  
Mahmood Mahmoodi ◽  
Zabihollah Shoja ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Neurological Diseases ◽  
Age Groups ◽  
Enterovirus 71 ◽  
Neutralizing Antibody ◽  
Human Enterovirus ◽  
Healthy Individuals ◽  
Serum Samples ◽  
Cross Sectional ◽  
Human Enterovirus 71

Background and Objectives: Human Enterovirus 71 (EV-A71) is the causative agent for many dermal to neurological diseases especially polio-like paralysis outbreaks around the world. This study, the first of this kind in Iran, aimed to find neu- tralizing antibodies against EV-A71 in serum of healthy individuals in different age groups based on neutralization test (NT). Materials and Methods: In this cross-sectional study, 547 serum samples were collected from healthy individuals who were referring for routine checkup tests (aged from under 6 months to over 31 years old) to Imam-Khomeini Hospital in Tehran during January-December 2015. Serum samples were examined by NT in cell culture to detect neutralizing antibodies against EV-A71. In the next step, some of the positive samples were subjected to complete titration to determine the exact titer of anti-EV-A71 antibodies. Results: Of 547 samples, 310 (56.7%) were positive for EV-A71 neutralizing antibody. The presence of the antibody in- creased with age (p<0.001), and there was a significant statistical relationship between sex and the presence of antibody (p=0.009). Conclusion: Our results demonstrated an apparent but limited circulation of EV-A71 in our society. After the worldwide eradication of poliovirus, EV-A71 which can cause polio-likes syndrome, might be the new challenge for our health care system as regard more in depth research is however needed.

scholarly journals A multiplexed high-throughput neutralization assay reveals a lack of activity against multiple variants after SARS-CoV-2 infection

2021 ◽  
Author(s):  
Craig Fenwick ◽  
Priscilla Turelli ◽  
Celine Pellaton ◽  
Alex Farina ◽  
Jeremy Campos ◽  
...  
Keyword(s):  
High Throughput ◽  
Neutralizing Antibodies ◽  
Large Scale ◽  
Competitive Inhibition ◽  
Natural Infection ◽  
Neutralizing Antibody ◽  
Neutralization Assay ◽  
Antibody Responses ◽  
Serum Samples ◽  
Live Virus

The detection of SARS-CoV-2-specific antibodies in the serum of an individual indicates prior infection or vaccination. However, it provides limited insight into the protective nature of this immune response. Neutralizing antibodies recognizing the viral Spike are far more revealing, yet their measurement traditionally requires virus- and cell-based systems that are costly, time-consuming, poorly flexible and potentially biohazardous. Here we present a cell-free quantitative neutralization assay based on the competitive inhibition of trimeric SARS-CoV-2 Spike protein binding to the angiotensin converting enzyme 2 (ACE2) viral receptor. This high-throughput method matches the performance of the gold standard live virus infectious assay, as verified with a panel of 206 seropositive donors with varying degrees of infection severity and virus-specific IgG titers, achieving 96.7% sensitivity and 100% specificity. Furthermore, it allows for the parallel assessment of neutralizing activities against multiple SARS-CoV-2 Spike variants of concern (VOC), which is otherwise unpredictable even in individuals displaying robust neutralizing antibody responses. Profiling serum samples from 59 hospitalized COVID-19 patients, we found that although most had high activity against the 2019-nCoV Spike and to a lesser extent the B.1.1.7 variant, only 58% could efficiently neutralize a Spike derivative containing mutations present in the B.1.351 variant. In conclusion, we have developed an assay that has proven its clinical relevance in the large-scale evaluation of effective neutralizing antibody responses to VOC after natural infection and that can be applied to the characterization of vaccine-induced antibody responses and of the potency of human monoclonal antibodies.

scholarly journals Role of human epididymis protein 4 for detection of ovarian carcinoma in adnexal masses: A pilot study

2016 ◽  
Author(s):  
Nidhi Bansal ◽  
A. Suneja ◽  
K. Guleria ◽  
N. B. Vaid ◽  
K. Mishra ◽  
...  
Keyword(s):  
Diagnostic Accuracy ◽  
Cross Sectional Study ◽  
Ca 125 ◽  
Serum Samples ◽  
Cross Sectional ◽  
Adnexal Masses ◽  
Good Discriminator ◽  
Risk Of Malignancy ◽  
Risk Of Malignancy Index ◽  
Benign Tumours

Introduction: HE4 is a novel tumour biomarker used for early diagnosis of ovarian cancer. This study evaluated the diagnostic accuracy of HE4 alone and in combination with CA125, risk of malignancy index (RMI), risk of malignancy algorithm (ROMA). Methods: It was a cross sectional study conducted recruiting 88 women with adnexal masses who were planned for surgery. After baseline work up and ultrasound examination, serum samples were collected for estimation of CA 125 and HE4 levels. Serum HE4 levels were estimated using ELISA kit. RMI and ROMA score were calculated and diagnostic accuracy of HE4, CA 125, RMI, ROMA and their combination were compared. Cut off for HE4 and ROMA score were calculated using ROC curve. Results: Of 88 subjects, 66 were analyzed with 19 malignant (including 5 LMP) and 47 benign cases. The median value of HE4 among malignant cases was found to be significantly higher than among the benign cases. PPV and NPV of HE4 at a cut off 130.8 pMol/ml was 85.7% and 77.9% respectively. Highest PPV (88.9%) with acceptable NPV (80.7%) was found with ROMA followed by HE4 (PPV 85.7%; NPV 77.97%), RMI (PPV 76.92%; NPV 83%) and CA125 (PPV 52%; NPV 80.85%). Conclusion: HE4 levels were lower in Indian population both in malignant and benign tumours as compared to other studies. HE4 is a good discriminator and gives best accuracy when it is combined with CA125 in a logistic algorithm, ROMA.

scholarly journals Evaluation of a Pseudovirus Neutralization Assay for SARS-CoV-2 and Correlation with Live Virus-Based Micro Neutralization Assay

Diagnostics ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 994
Author(s):  
Ahmed Majdi K. Tolah ◽  
Sayed S. Sohrab ◽  
Khaled Majdi K. Tolah ◽  
Ahmed M. Hassan ◽  
Sherif A. El-Kafrawy ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Epidemiological Studies ◽  
Neutralization Assay ◽  
Serum Samples ◽  
Live Virus ◽  
Spike Gene ◽  
Microneutralization Assay ◽  
Viral Particles ◽  
Reliable Performance ◽  
Prior Infection

The unusual cases of pneumonia outbreak were reported from Wuhan city in late December 2019. Serological testing provides a powerful tool for the identification of prior infection and for epidemiological studies. Pseudotype virus neutralization assays are widely used for many viruses and applications in the fields of serology. The accuracy of pseudotype neutralizing assay allows for its use in low biosafety lab and provides a safe and effective alternative to the use of wild-type viruses. In this study, we evaluated the performance of this assay compared to the standard microneutralization assay as a reference. The lentiviral pseudotype particles were generated harboring the Spike gene of SARS-CoV-2. The generated pseudotype particles assay was used to evaluate the activity of neutralizing antibodies in 300 human serum samples from a COVID-19 sero-epidemiological study. Testing of these samples resulted in 55 positive samples and 245 negative samples by pseudotype viral particles assay while microneutralization assay resulted in 64 positive and 236 negative by MN assay. Compared to the MN, the pseudotyped viral particles assay showed a sensitivity of 85.94% and a specificity of 100%. Based on the data generated from this study, the pseudotype-based neutralization assay showed a reliable performance for the detection of neutralizing antibodies against SARS-CoV-2 and can be used safely and efficiently as a diagnostic tool in a biosafety level 2 laboratory.

scholarly journals SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020

2021 ◽  
Vol 9 (4) ◽  
pp. 850
Author(s):  
José Esteban Muñoz-Medina ◽  
Concepción Grajales-Muñiz ◽  
Angel Gustavo Salas-Lais ◽  
Larissa Fernandes-Matano ◽  
Constantino López-Macías ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Neutralizing Antibodies ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Neutralizing Activity

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico’s first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

Sign in / Sign up

Export Citation Format

Share Document