scholarly journals Longitudinal observation of antibody responses after SARS-CoV-2 infection at 14 months

2021 ◽  
Author(s):  
Asiya kamber Zaidi ◽  
Puya Dehgani-Mobaraki ◽  
Nidhi Yadav ◽  
Alessandro Floridi
Keyword(s):  
Natural Infection ◽  
False Negative ◽  
Previous History ◽  
False Negative Rate ◽  
Severe Infection ◽  
Antibody Responses ◽  
Igg Antibody ◽  
Serological Tests ◽  
Significant Positive Association ◽  
Antibody Titers

Abstract A better understanding regarding antibody responses against SARS-CoV-2 after natural infection could provide valuable insights into the future implementation of vaccination policies. In this study, we aimed to assess the dynamics of IgG antibody titers in recovered COVID-19 patients over 14 months after mild and moderately severe infection using two FDA-approved immunoassays against SARS-CoV-2 Nucleocapsid protein (NCP)and anti-spike-receptor binding domain (S-RBD) through sequential serological tests at different time points. The demographics and clinical profile, that might be associated with the magnitude and longevity of antibody response were also analyzed. Our results suggest antibody persistency in 31 out of 32 (96.8%) subjects at 14 months post-infection. A significant positive association was observed between disease severity and anti-S-RBD IgG titers at 14 months. Patients who reported a loss of smell and taste during the clinical course of the disease also developed significantly better antibody titers. Patients who were seronegative for anti-NCP IgG (n=7) at 10 months, were found to be seropositive for anti-S-RBD IgG at 12,13 and 14 months emphasizing on higher false-negative rate for N protein-based antibody assays when compared with the anti-S-RBD assays. This study calls for prioritizing vaccination for “naive” individuals (with no previous history of COVID-19 infection) and recovered but antibody-negative individuals instead of “vaccination for all”. This strategy would be helpful in low-resource settings and areas experiencing vaccine shortages by saving time, effort, and assets that could be sourced for the vulnerable populations.

scholarly journals SARS-CoV-2 Vaccine-Induced Antibody Response and Reinfection in Persons with Past Natural Infection

2021 ◽  
Author(s):  
Nitu Chauhan ◽  
Ajeet Singh Chahar ◽  
Prem Singh ◽  
Neel Sarovar Bhavesh ◽  
Ravi Tandon ◽  
...  
Keyword(s):  
Viral Vector ◽  
Natural Infection ◽  
Previous History ◽  
Adenovirus Vector ◽  
Prior History ◽  
Igg Antibody ◽  
Vector Vaccine ◽  
Women Subjects ◽  
History Of ◽  
Antibody Titers

Several studies have shown that subjects with a history of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection had significantly higher antibody titers than previously uninfected vaccinees after vaccination with mRNA vaccine. Yet no information is available for other vaccines. In the current observational cohort study, 105 health care workers who had received Covishield an Adeno associated viral vector-based DNA vaccine were enrolled at Sarojini Nadu Medical College Agra, India. The study included 40 (23 men and 17 women) subjects with a previous history of SARS-CoV-2 infection and 65 participants (39 men and 26 women) who were not infected previously. Both the groups received the adenovirus vector vaccine ChAdOx1-S recombinant vaccines (Covishield, Astra Zeneca). The levels of SARS-CoV-2-anti-spike-IgG-antibodies titer were measured using Electrochemiluminescence immunoassay on Roche platform as arbitrary units per milliliter (AU/ml). After 28 days of the second dose, subjects with no previous SARSCoV-2 infection showed a significantly lower level of circulating anti-spike-IgG-antibody titers compared to previously infected participants. After the second dose, we also observed a significant increase in SARS-CoV-2 infection in subjects with no prior history of SARS-CoV-2 infection compared to subjects with a previous history of natural infection. The most important observation of the study is a low percentage of infection in previously infected subjects. The finding of the study also indicates the presence of robust humoral memory response in previously infected patients.

scholarly journals Simultaneous Immunization with Multiple Diverse Immunogens Alters Development of Antigen-Specific Antibody-Mediated Immunity

Vaccines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 964
Author(s):  
Kelsey A. Pilewski ◽  
Kevin J. Kramer ◽  
Ivelin S. Georgiev
Keyword(s):  
Specific Antibody ◽  
Antibody Responses ◽  
Surface Proteins ◽  
Emerging Pathogens ◽  
Igg Antibody ◽  
Neisseria Meningitides ◽  
Immunization Strategies ◽  
Single Antigen ◽  
The Face ◽  
Antibody Titers

Vaccination remains one of the most successful medical interventions in history, significantly decreasing morbidity and mortality associated with, or even eradicating, numerous infectious diseases. Although traditional immunization strategies have recently proven insufficient in the face of many highly mutable and emerging pathogens, modern strategies aim to rationally engineer a single antigen or cocktail of antigens to generate a focused, protective immune response. However, the effect of cocktail vaccination (simultaneous immunization with multiple immunogens) on the antibody response to each individual antigen within the combination, remains largely unstudied. To investigate whether immunization with a cocktail of diverse antigens would result in decreased antibody titer against each unique antigen in the cocktail compared to immunization with each antigen alone, we immunized mice with surface proteins from uropathogenic Escherichia coli, Mycobacterium tuberculosis, and Neisseria meningitides, and monitored the development of antigen-specific IgG antibody responses. We found that antigen-specific endpoint antibody titers were comparable across immunization groups by study conclusion (day 70). Further, we discovered that although cocktail-immunized mice initially elicited more robust antibody responses, the rate of titer development decreases significantly over time compared to single antigen-immunized mice. Investigating the basic properties that govern the development of antigen-specific antibody responses will help inform the design of future combination immunization regimens.

scholarly journals Syphilitic Balanitis of Follmann: Laboratory Pitfalls

2020 ◽  
Vol 78 (3) ◽  
pp. 265-268
Author(s):  
Filipa Tavares Almeida ◽  
Filomena Azevedo ◽  
Carmen Lisboa
Keyword(s):  
Infected Patient ◽  
False Negative ◽  
Previous History ◽  
Syphilis Infection ◽  
Flocculation Test ◽  
History Of ◽  
Antibody Titers ◽  
Lattice Network ◽  
Antigen Antibody ◽  
Prozone Phenomenon

We report a case of early syphilis, presenting as balanitis and papular syphilides in an HIV-infected patient, with a previous history of syphilis infection, which demonstrated a false negative VDRL testing due to a prozone phenomenon. This false negative response results from overwhelming antibody titers, which interfere with the proper formation of the antigen-antibody lattice network, necessary to visualize a positive flocculation test.

scholarly journals Protective Immune Responses to the 42-Kilodalton (kDa) Region of Plasmodium yoelii Merozoite Surface Protein 1 Are Induced by the C-Terminal 19-kDa Region but Not by the Adjacent 33-kDa Region

2002 ◽  
Vol 70 (2) ◽  
pp. 820-825 ◽  
Author(s):  
Niklas Ahlborg ◽  
Irene T. Ling ◽  
Wendy Howard ◽  
Anthony A. Holder ◽  
Eleanor M. Riley
Keyword(s):  
Gene Segment ◽  
Surface Protein ◽  
Merozoite Surface Protein ◽  
Plasmodium Yoelii ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Merozoite Surface Protein 1 ◽  
Antibody Titers ◽  
Processing Product

ABSTRACT Vaccination of mice with the 42-kDa region of Plasmodium yoelii merozoite surface protein 1 (MSP142) or its 19-kDa C-terminal processing product (MSP119) can elicit protective antibody responses in mice. To investigate if the 33-kDa N-terminal fragment (MSP133) of MSP142 also induces protection, the gene segment encoding MSP133 was expressed as a glutathione S-transferase (GST) fusion protein. C57BL/6 and BALB/c mice were immunized with GST-MSP133 and subsequently challenged with the lethal P. yoelii YM blood stage parasite. GST-MSP133 failed to induce protection, and all mice developed patent parasitemia at a level similar to that in naive or control (GST-immunized) mice; mice immunized with GST-MSP119 were protected, as has been shown previously. Specific prechallenge immunoglobulin G (IgG) antibody responses to MSP1 were analyzed by enzyme-linked immunosorbent assay and immunofluorescence. Despite being unprotected, several mice immunized with MSP133 had antibody titers (of all IgG subclasses) that were comparable to or higher than those in mice that were protected following immunization with MSP119. The finding that P. yoelii MSP133 elicits strong but nonprotective antibody responses may have implications for the design of vaccines for humans based on Plasmodium falciparum or Plasmodium vivax MSP142.

scholarly journals A Modified Enzyme-Linked Immunosorbent Assay for Measurement of Antibody Responses to Meningococcal C Polysaccharide That Correlate with Bactericidal Responses

1998 ◽  
Vol 5 (4) ◽  
pp. 479-485 ◽  
Author(s):  
Dan M. Granoff ◽  
Susan E. Maslanka ◽  
George M. Carlone ◽  
Brian D. Plikaytis ◽  
George F. Santos ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Geometric Mean ◽  
Correlation Coefficients ◽  
Antibody Responses ◽  
Enzyme Linked Immunosorbent Assay ◽  
High Avidity ◽  
Igg Antibody ◽  
Standard Assay ◽  
Bactericidal Antibody ◽  
Antibody Titers

ABSTRACT The standardized enzyme-linked immunosorbent assay (ELISA) for measurement of serum immunoglobulin G (IgG) antibody responses to meningococcal C polysaccharide has been modified to employ assay conditions that ensure specificity and favor detection primarily of high-avidity antibodies. The modified and standard assays were used to measure IgG antibody concentrations in sera of toddlers vaccinated with meningococcal polysaccharide vaccine or a meningococcal C conjugate vaccine. The results were compared to the respective complement-mediated bactericidal antibody titers. In sera obtained after one or two doses of vaccine, the correlation coefficients, r, for the results of the standard assay and bactericidal antibody titers were 0.45 and 0.29, compared to 0.85 and 0.87, respectively, for the modified assay. With the standard assay, there were no significant differences between the geometric mean antibody responses of the two vaccine groups. In contrast, with the modified assay, 5- to 20-fold higher postvaccination antibody concentrations were measured in the conjugate than in the polysaccharide group. Importantly, the results of the modified assay, but not the standard ELISA, paralleled the respective geometric mean bactericidal antibody titers. Thus, by employing conditions that favor detection of higher-avidity IgG antibody, the modified ELISA provides results that correlate closely with measurements of antibody functional activity that are thought to be important in protection against meningococcal disease.

scholarly journals Serological Diagnosis of Human Herpes Simplex Virus Type 1 and 2 Infections by Luciferase Immunoprecipitation System Assay

2009 ◽  
Vol 16 (3) ◽  
pp. 366-371 ◽  
Author(s):  
Peter D. Burbelo ◽  
Yo Hoshino ◽  
Hannah Leahy ◽  
Tammy Krogmann ◽  
Ronald L. Hornung ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Western Blotting ◽  
Antibody Responses ◽  
Plasma Samples ◽  
Serological Tests ◽  
Antibody Titers ◽  
Simplex Virus ◽  
Humoral Responses ◽  
Hsv 1

ABSTRACT Highly quantitative and high-throughput serological tests for evaluation of humoral responses to herpes simplex virus 1 (HSV-1) and HSV-2 are not available. The efficacy of luciferase immunoprecipitation system (LIPS) assays for antibody profiling and serologic diagnosis of HSV-1 and HSV-2 infection was investigated using a panel of five recombinant HSV antigens. Plasma samples from subjects seropositive for HSV-1 and/or HSV-2 or seronegative for HSV-1 and HSV-2 that had previously been analyzed by Western blotting and the Focus Plexus immunoassay were evaluated. The LIPS test measuring anti-gG1 antibody titers was 96% sensitive and 96% specific for detecting HSV-1 infection, compared with the Focus immunoassay, and was 92% sensitive and 96% specific, compared with Western blotting. The results for the anti-gG2 LIPS test for HSV-2 precisely matched those for Western blotting, with 100% sensitivity and 100% specificity, and showed robust antibody titers in all the HSV-2-infected samples that were over 1,000 times higher than those in HSV-2-negative or HSV-1-positive samples. Antibodies to three additional HSV-2 proteins, gB, gD, and ICP8, were detected in many of the HSV-1- and/or HSV-2-infected plasma samples and showed preferentially higher immunoreactivity in HSV-2-infected plasma. The titers of antibodies to these three HSV-2 antigens also significantly correlated with each other (R = 0.75 to 0.81; P < 0.0001). These studies indicate that the robust anti-gG1 and anti-gG2 antibody responses detected by LIPS assays are useful for HSV-1 and HSV-2 detection and suggest that profiling of antibody responses to a panel of HSV proteins may be useful for characterizing individual humoral responses to infection and for monitoring responses to vaccines.

scholarly journals Early Diagnosis and Treatment of Patients with Symptomatic Acute Q Fever Do Not Prohibit IgG Antibody Responses to Coxiella burnetii

2012 ◽  
Vol 19 (10) ◽  
pp. 1661-1666 ◽  
Author(s):  
C. C. H. Wielders ◽  
L. M. Kampschreur ◽  
P. M. Schneeberger ◽  
M. M. Jager ◽  
A. I. M. Hoepelman ◽  
...  
Keyword(s):  
Early Diagnosis ◽  
Phase I ◽  
Phase Ii ◽  
Coxiella Burnetii ◽  
Q Fever ◽  
Antibody Responses ◽  
Igg Antibody ◽  
Antibody Titers ◽  
Acute Q Fever

ABSTRACTLittle is known about the effect of timing of antibiotic treatment on development of IgG antibodies following acute Q fever. We studied IgG antibody responses in symptomatic patients diagnosed either before or during development of the serologic response toCoxiella burnetii. Between 15 and 31 May 2009, 186 patients presented with acute Q fever, of which 181 were included in this retrospective study: 91 early-diagnosed (ED) acute Q fever patients, defined as negative IgM phase II enzyme-linked immunosorbent assay (ELISA) and positive PCR, and 90 late-diagnosed (LD) acute Q fever patients, defined as positive/dubious IgM phase II ELISA and positive immunofluorescence assay (IFA). Follow-up serology at 3, 6, and 12 months was performed using IFA (IgG phase I and II). High IgG antibody titers were defined as IgG phase II titers of ≥1:1,024 together with IgG phase I titers of ≥1:256. At 12 months, 28.6% of ED patients and 19.5% of LD patients had high IgG antibody titers (P= 0.17). No statistically significant differences were found in frequencies of IgG phase I and IgG phase II antibody titers at all follow-up appointments for adequately and inadequately treated patients overall, as well as for ED and LD patients analyzed separately. Additionally, no significant difference was found in frequencies of high antibody titers and between early (treatment started within 7 days after seeking medical attention) and late timing of treatment. This study indicates that early diagnosis and antibiotic treatment of acute Q fever do not prohibit development of the IgG antibody response.

scholarly journals Immune response to SARS-CoV-2 variants of concern in vaccinated individuals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Matthias Becker ◽  
Alex Dulovic ◽  
Daniel Junker ◽  
Natalia Ruetalo ◽  
Philipp D. Kaiser ◽  
...  
Keyword(s):  
South African ◽  
Neutralizing Antibodies ◽  
Substantial Reduction ◽  
Humoral Response ◽  
Antibody Responses ◽  
Igg Antibody ◽  
Transmission Potential ◽  
Know How ◽  
Mutant Strains ◽  
Antibody Titers

AbstractSARS-CoV-2 is evolving with mutations in the receptor binding domain (RBD) being of particular concern. It is important to know how much cross-protection is offered between strains following vaccination or infection. Here, we obtain serum and saliva samples from groups of vaccinated (Pfizer BNT-162b2), infected and uninfected individuals and characterize the antibody response to RBD mutant strains. Vaccinated individuals have a robust humoral response after the second dose and have high IgG antibody titers in the saliva. Antibody responses however show considerable differences in binding to RBD mutants of emerging variants of concern and substantial reduction in RBD binding and neutralization is observed against a patient-isolated South African variant. Taken together our data reinforce the importance of the second dose of Pfizer BNT-162b2 to acquire high levels of neutralizing antibodies and high antibody titers in saliva suggest that vaccinated individuals may have reduced transmission potential. Substantially reduced neutralization for the South African variant further highlights the importance of surveillance strategies to detect new variants and targeting these in future vaccines.

scholarly journals Serological immunochromatographic approach in diagnosis with SARS-CoV-2 infected COVID-19 patients

2020 ◽  
Author(s):  
Yunbao Pan ◽  
Xinran Li ◽  
Gui Yang ◽  
Junli Fan ◽  
Yueting Tang ◽  
...  
Keyword(s):  
Real Time ◽  
Early Stage ◽  
False Negative ◽  
False Negative Rate ◽  
Intermediate Stage ◽  
Rt Pcr ◽  
Igg Antibody ◽  
Blood Samples ◽  
Icg Strip ◽  
Stage 1

AbstractAn outbreak of new coronavirus SARS-CoV-2 was occurred in Wuhan, China and rapidly spread to other cities and nations. The standard diagnostic approach that widely adopted in the clinic is nuclear acid detection by real-time RT-PCR. However, the false-negative rate of the technique is unneglectable and serological methods are urgently warranted. Here, we presented the colloidal gold-based immunochromatographic (ICG) strip targeting viral IgM or IgG antibody and compared it with real-time RT-PCR. The sensitivity of ICG assay with IgM and IgG combinatorial detection in nuclear acid confirmed cases were 11.1%, 92.9% and 96.8% at the early stage (1-7 days after onset), intermediate stage (8-14 days after onset), and late stage (more than 15 days), respectively. The ICG detection capacity in nuclear acid-negative suspected cases was 43.6%. In addition, the consistencies of whole blood samples with plasma were 100% and 97.1% in IgM and IgG strips, respectively. In conclusion, serological ICG strip assay in detecting SARS-CoV-2 infection is both sensitive and consistent, which is considered as an excellent supplementary approach in clinical application.

Comparison of Covid-19 IgG Anti-Spike Antibody Titer after Vaccination with Sputnik V in Seropositive and Naïve Vaccinees

2021 ◽  
Vol 35 (4) ◽  
pp. 1-5
Author(s):  
Hajra Farooq
Keyword(s):  
Single Dose ◽  
Antibody Titer ◽  
Immunological Response ◽  
Severe Infection ◽  
P Value ◽  
Igg Antibody ◽  
Policy Makers ◽  
Significant Difference ◽  
Antibody Titers ◽  
Study Participants

Introduction: Immunity to SARS-CoV-2 has shown to reduce the risk of having a severe infection and initiate a good degree of disease protection. Studies assessing the antibody titer after vaccination can be very helpful to see whether previously infected individuals have better immunological response as compared to uninfected or antibody naïve individuals. Aims & Objectives: Comparison of Anti-spike IgG antibody among vaccinees with or without previous exposure to COVID-19. To determine whether single dose regimen can produce significant antibody titer amongst previously infected cases and design vaccine dosage regimens accordingly. Place and duration of study: This study was conducted at Chughtai Institute of Pathology from April 2021 to June 2021. Material & Methods: Blood samples were collected from 83 adult male and female vaccinees at baseline, 3 weeks after the first dose and finally 7 days after the second dose. Previously infected individuals’ record was noted separately. Samples were immediately analyzed using Abbott SARS-CoV-2 IgG II quant two step immunoassay. Data was analyzed using SPSS 23.0. A p-value of <0.05 was considered significant.Results: Majority of the candidates (57 %) were females and on analysis it was found that 42% of the patients were seropositive whereas 58% of the patients were antibody naïve before receiving the first dose of vaccine. There was a significant difference between mean antibody titer of seropositive and seronegative study participants at day 0, day 21 and finally on day 28 (p value <0.001) with seropositive individuals having higher antibody titers even after first vaccine shot. Conclusion: Post vaccination immunological response was higher in seropositive individuals as compared to the antibody naïve and this finding can help the policy makers to design a single dose vaccine regimen for the former category.

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