scholarly journals Stable IgG-antibody levels in patients with mild SARS-CoV-2 infection

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.

Author(s):  
Gerco den Hartog ◽  
Eric R A Vos ◽  
Lotus L van den Hoogen ◽  
Michiel van Boven ◽  
Rutger M Schepp ◽  
...  

Abstract Background Assessing the duration of immunity following infection with SARS-CoV-2 is a first priority to gauge the degree of protection following infection. Such knowledge is lacking especially in the general population. Here, we studied changes in Immunoglobulin (Ig) isotype seropositivity and IgG binding strength of SARS-CoV-2-specific serum antibodies up to 7 months following onset of symptoms in a nationwide sample. Methods Participants from a prospective representative serological study in the Netherlands were included based on IgG seroconversion to the Spike S1 protein of SARS-CoV-2 (N=353), with up to three consecutive serum samples per seroconverted participant (N=738). IgM, IgA and IgG antibody concentrations to S1, and increase in IgG avidity in relation to time since onset of disease symptoms, were determined. Results While SARS-CoV-2-specific IgM and IgA antibodies declined rapidly after the first month post onset of disease, specific IgG was still present in 92% (95% confidence interval, CI, 89-95) of the participants after 7 months. The estimated 2-fold decrease of IgG antibodies was 158 days (95% CI 136-189). Concentrations sustained better in persons reporting significant symptoms compared to asymptomatic persons or those with mild upper respiratory complaints only. Similarly, avidity of IgG antibodies for symptomatic persons showed a steeper increase over time compared with persons with mild or no symptoms (p=0.022). Conclusion SARS-CoV-2-specific IgG antibodies persist and show increasing avidity over time, indicative of underlying immune maturation. These data support development of immune memory against SARS-CoV-2 providing insight into protection of the general unvaccinated part of the population.


Author(s):  
Georg Semmler ◽  
Marianna Theresia Traugott ◽  
Marianne Graninger ◽  
Wolfgang Hoepler ◽  
Tamara Seitz ◽  
...  

In this study, we comprehensively analyzed multispecific antibody kinetics of different immunoglobulins in hospitalized patients with acute SARS-CoV-2 infection. Three-hundred-fifty-four blood samples longitudinally obtained from 81 IgG seroconverting CoVID-19 patients were quantified for spike (S)1, S2, and nucleocapsid protein (NCP)- specific IgM, IgA, IgG, and total Ig antibodies using a microarray, eleven different ELISAs/CLIAs, and one rapid test by seven manufacturers. The assays’ specificity was assessed in 130 non-CoVID19 pneumonia patients. Using the microarray, NCP-specific IgA and IgG antibodies continuously displayed higher detection rates during acute CoVID-19 than S1- and S2-specific ones. S1-specific IgG antibodies, however, reached higher peak values. Until the 26th-day post symptom onset, all patients developed IgG responses against S1, S2, and NCP, respectively. Although detection rates by ELISAs/CLIAs generally resembled those of the microarray, corresponding to the target antigen, sensitivities and specificities varied among all tests. Notably, patients with more severe CoVID-19 displayed higher IgG and IgA levels, but this difference was mainly observed with S1-specific immunoassays. In patients with high SARS-CoV-2 levels in the lower respiratory tract, we observed high detection rates of IgG and total Ig immunoassays with a particular rise of S1-specific IgG antibodies when viral concentrations in the tracheal aspirate subsequently declined over time. In summary, our study demonstrates that differences in sensitivity among commercial immunoassays during acute SARS-CoV-2 infection are only partly related to the target antigen. Importantly, our data indicate that NCP-specific IgA and IgG antibodies are detected earlier, while higher S1-specific IgA antibody levels occur in severely ill patients.


BMJ Open ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. e053791
Author(s):  
S Muhammad Salim Khan ◽  
Mariya Amin Qurieshi ◽  
Inaamul Haq ◽  
Sabhiya Majid ◽  
Javid Ahmad ◽  
...  

ObjectivesWe designed a population-based survey in Kashmir to estimate the seroprevalence of SARS-CoV-2-specific IgG antibodies in the general population aged 18 years and above.SettingThe survey was conducted among 110 villages and urban wards across 10 districts in Kashmir from 17 October 2020 to 4 November 2020.ParticipantsIndividuals aged 18 years and above were eligible to be included in the survey. Serum samples were tested for the presence of SARS-CoV-2-specific IgG antibodies using the Abbott SARS-CoV-2 IgG assay.Primary and secondary outcome measuresWe labelled assay results equal to or above the cut-off index value of 1.4 as positive for SARS-CoV-2-specific IgG antibodies. Seroprevalence estimates were adjusted for the sampling design and assay characteristics.ResultsOut of 6397 eligible individuals enumerated, 6315 (98.7%) agreed to participate. The final analysis was done on 6230 participants. Seroprevalence adjusted for the sampling design and assay characteristics was 36.7% (95% CI 34.3% to 39.2%). Seroprevalence was higher among the older population. Among seropositive individuals, 10.2% (247/2415) reported a history of COVID-19-like symptoms. Out of 474 symptomatic individuals, 233 (49.2%) reported having been tested. We estimated an infection fatality rate of 0.034%.ConclusionsDuring the first 7 months of the COVID-19 epidemic in Kashmir Valley, approximately 37% of individuals were infected. The reported number of COVID-19 cases was only a small fraction of the estimated number of infections. A more efficient surveillance system with strengthened reporting of COVID-19 cases and deaths is warranted.


2021 ◽  
Author(s):  
Calvin P Sjaarda ◽  
Emily Moslinger ◽  
Kyla Tozer ◽  
Robert I Colautti ◽  
Samira Kheitan ◽  
...  

Background. Antibody responses to SARS-CoV-2 can be observed as early as 14 days post- infection, but little is known about the stability of antibody levels over time. Here we evaluate the long-term stability of anti-SARS-CoV-2 IgG antibodies following infection in 402 adult donors. Methods. We performed a multi-centre study carried out at Plasma Donor Centres in the city of Heidelberg (Plasmazentrum Heidelberg, Germany) and Munich (Plasmazentrum M&uumlnchen, Germany). We present anti-S/N and anti-N IgG antibody levels in prospective serum samples collected up to 403 days post recovery from SARS-CoV-2 infected individuals. Results: The cohort includes 402 adult donors (185 female, 217 male; 17 - 68 years of age) where anti-SARS-CoV-2 IgG levels were measured in plasma samples collected between 18- and 403-days post SARS-CoV-2 infection. A linear mixed effects model demonstrated IgG decay rates that decrease over time (χ2=176.8, p<0.00001) and an interaction of time*age (χ2=10.0, p<0.005)), with those over 60+ years showing the highest baseline IgG levels and the fastest rate of IgG decay. Baseline viral neutralization assays demonstrated that serum IgG levels correlated with in vitro neutralization capacity in 91% of our cohort. Conclusion. Long-term antibody levels and age-specific antibody decay rates suggest the potential need for age-specific vaccine booster guidelines to ensure long term vaccine protection against SARS-CoV-2 infection.


Author(s):  
V.T. Akhmetshina ◽  
◽  
L.G. Gizatullina ◽  
L.M. Masyagutova

Abstract: Abstract: Today, a request is being formed to prevent the introduction of infection into organized groups by means of the formation of population immunity by methods of specific prevention. Purpose of the work: To carry out the determination of specific IgG antibodies to SARS-CoV-2 in students of a higher educational institution, to determine the number of students in need of vaccination. Material and research methods: The level of IgG antibodies to SARS-CoV-2 in the blood serum of students of a higher educational institution was analyzed. An analysis of the strength of immunity shows that the average value of the CP of positive samples is 11.3. A more significant diagnostic level of CP was revealed, indicating a pronounced tension of immunity in students with a history of pneumonia. Among those with a diagnostically significant positive CP level, more than a third of the examined subjects have lower IgG antibodies to SARS-CoV-2 than the average in this group. Consequently, these individuals require dynamic observation and monitoring of antibody levels in order to ensure timely vaccination. Thus, specific IgG antibodies to SARS-CoV-2 were detected in half of the examined students, which was 55%. It is this group that is subject to immediate vaccination before undergoing industrial practice. A third of students with low levels of antibodies to SARS-CoV-2 need dynamic monitoring of their content.


2003 ◽  
Vol 10 (6) ◽  
pp. 1043-1050 ◽  
Author(s):  
Ketil Moen ◽  
Johan G. Brun ◽  
Tor Magne Madland ◽  
Turid Tynning ◽  
Roland Jonsson

ABSTRACT The objective of the present study was to investigate immunoglobulin G (IgG) and IgA antibody immune responses to Porphyromonas gingivalis, Prevotella intermedia, Bacteroides forsythus, and Candida albicans in the sera of patients with rheumatoid arthritis (RA), the synovial fluid (SF) of patients with RA (RA-SF samples), and the SF of patients without RA (non-RA-SF samples). An enzyme-linked immunosorbent assay was used to determine IgG and IgA antibody levels in 116 serum samples from patients with RA, 52 RA-SF samples, and 43 non-RA-SF samples; and these were compared with those in SF samples from 9 patients with osteoarthritis (OA-SF samples) and the blood from 100 donors (the control [CTR] group). Higher levels of IgG antibodies against B. forsythus (P < 0.0001) and P. intermedia (P < 0.0001) were found in non-RA-SF samples than in OA-SF samples, and higher levels of IgG antibodies against B. forsythus (P = 0.003) and P. intermedia (P = 0.024) were found in RA-SF samples than in OA-SF samples. Significantly higher levels of IgA antibodies against B. forsythus were demonstrated in both RA-SF and non-RA-SF samples than in OA-SF samples. When corrected for total Ig levels, levels of IgG antibody against B. forsythus were elevated in RA-SF and non-RA-SF samples compared to those in OA-SF samples. Lower levels of Ig antibodies against B. forsythus were found in the sera of patients with RA than in the plasma of the CTR group for both IgG (P = 0.003) and IgA (P < 0.0001). When corrected for total Ig levels, the levels of IgG and IgA antibodies against B. forsythus were still found to be lower in the sera from patients with RA than in the plasma of the CTR group (P < 0.0001). The levels of antibodies against P. gingivalis and C. albicans in the sera and SF of RA and non-RA patients were comparable to those found in the respective controls. The levels of IgG and IgA antibodies against B. forsythus were elevated in SF from patients with RA and non-RA-SF samples compared to those in OA-SF samples. Significantly lower levels of IgG and IgA antibodies against B. forsythus were found in the sera of patients with RA than in the plasma of the CTR group. This indicates the presence of an active antibody response in synovial tissue and illustrates a potential connection between periodontal and joint diseases.


BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e048142
Author(s):  
Louise J Robertson ◽  
Julie S Moore ◽  
Kevin Blighe ◽  
Kok Yew Ng ◽  
Nigel Quinn ◽  
...  

ObjectiveTo evaluate the dynamics and longevity of the humoral immune response to SARS-CoV-2 infection and assess the performance of professional use of the UK-RTC AbC-19 Rapid Test lateral flow immunoassay (LFIA) for the target condition of SARS-CoV-2 spike protein IgG antibodies.DesignNationwide serological study.SettingNorthern Ireland, UK, May 2020–February 2021.ParticipantsPlasma samples were collected from a diverse cohort of individuals from the general public (n=279), Northern Ireland healthcare workers (n=195), pre-pandemic blood donations and research studies (n=223) and through a convalescent plasma programme (n=183). Plasma donors (n=101) were followed with sequential samples over 11 months post-symptom onset.Main outcome measuresSARS-CoV-2 antibody levels in plasma samples using Roche Elecsys Anti-SARS-CoV-2 IgG/IgA/IgM, Abbott SARS-CoV-2 IgG and EuroImmun IgG SARS-CoV-2 ELISA immunoassays over time. UK-RTC AbC-19 LFIA sensitivity and specificity, estimated using a three-reference standard system to establish a characterised panel of 330 positive and 488 negative SARS-CoV-2 IgG samples.ResultsWe detected persistence of SARS-CoV-2 IgG antibodies for up to 10 months post-infection, across a minimum of two laboratory immunoassays. On the known positive cohort, the UK-RTC AbC-19 LFIA showed a sensitivity of 97.58% (95.28% to 98.95%) and on known negatives, showed specificity of 99.59% (98.53 % to 99.95%).ConclusionsThrough comprehensive analysis of a cohort of pre-pandemic and pandemic individuals, we show detectable levels of IgG antibodies, lasting over 46 weeks when assessed by EuroImmun ELISA, providing insight to antibody levels at later time points post-infection. We show good laboratory validation performance metrics for the AbC-19 rapid test for SARS-CoV-2 spike protein IgG antibody detection in a laboratory-based setting.


2001 ◽  
Vol 69 (2) ◽  
pp. 924-930 ◽  
Author(s):  
Shigetada Kawabata ◽  
Eiji Kunitomo ◽  
Yutaka Terao ◽  
Ichiro Nakagawa ◽  
Ken Kikuchi ◽  
...  

ABSTRACT The purpose of this study was to examine the suitability of fibronectin-binding protein FBP54 as a putative vaccine forStreptococcus pyogenes infections. When the distribution of the fbp54 gene among the clinical isolates representing various M serotypes was tested by PCR and Southern blot assays, it was found that all of the strains possess this gene. Furthermore, a significant increase in immunoglobulin G (IgG) antibody titers against FBP54 was observed in sera from patients with S. pyogenesinfections compared with those from healthy volunteers (P < 0.005). Mice were immunized with FBP54 subcutaneously, orally, or nasally. An enzyme-linked immunosorbent assay revealed that antigen-specific IgG antibodies were induced in the sera of immunized mice, while high salivary levels of IgA antibodies were detected after oral and nasal immunizations. Mice subcutaneously or orally immunized with FBP54 survived significantly longer following the challenge with S. pyogenes than did nonimmunized mice (P < 0.001). These results indicate that FBP54 is a promising vaccine for the prevention of S. pyogenesinfections.


2021 ◽  
Author(s):  
Guy Shapira ◽  
Ramzia Abu Hamad ◽  
Chen Weiner ◽  
Nir Rainy ◽  
Reut Sorek-Abramovich ◽  
...  

Neutralizing antibodies targeting the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) block viral entry to host cells, preventing disease and further spread of the pathogen. The presence of SARS-CoV-2 antibodies in serum is a reliable indicator of infection, used epidemiologically to estimate the prevalence of infection and clinically as a measurement of an antigen-specific immune response. In this study, we analyzed serum Spike protein-specific IgG antibodies from 26,170 samples, including convalescent individuals who had coronavirus disease 2019 (COVID-19) and recipients of the BNT162b2 vaccine. We find distinct serological patterns in COVID-19 convalescent and vaccinated individuals, correlated with age and gender and the presence symptoms.


F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 165
Author(s):  
Michael Walekhwa ◽  
Margaret Muturi ◽  
Elizabeth Bukusi

Introduction: This study aimed to determine the serum concentration of IgG antibodies as an indicator of immunogenicity, alongside the assessment of socio-demographic factors that affect IgG antibody levels in infants immunized with 10-valent pneumococcal conjugate vaccine (PCV-10) at the Mbagathi District Hospital in Kenya.Materials and methods: This cross-sectional study measured serum IgG antibodies among infants who had completed a 3-dose course of PCV-10. IgG antibodies to pneumococcal serotype-specific capsular polysaccharide were measured through enzyme-linked immunosorbent assay (ELISA).Results: The majority (83%) of infants who completed the required dose of pneumococcal conjugate vaccine had serum titres of pneumococcal disease- (PD) specific IgG antibodies of between 0.34 mg/dl and 0.36 mg/dl. 4% of infants had serum titres of 0.30 mg/dl to 0.33 mg/dl. The remaining 2% had IgG antibody titres of either ≤0.25 mg/dl, or between 0.25 mg/dl to 0.29 mg/dl. Additionally, there was multi-collinearity among the IgG antibody levels of the infants studied and several variables that had an effect on these levels. These included: alcohol consumption by infants’ biological mothers during pregnancy (r =.595, p ≤ 0.05); maternal diet during pregnancy (r =.137, p ≤ 0.05); breastfeeding frequency (r =.220, p ≤ 0.05); proximity to other children (r =.133, p ≤ 0.05); child hospitalization (r =.131, p ≤ 0.05) and chronic illness (r =.154, p ≤0.01).Conclusion: PCV-10 is immunogenic against PD four weeks after completion of 3-doses among the infants attending the Child Welfare clinic at the Mbagathi District Hospital in Kenya. Socio-demographic factors which include consumption of alcoholic drinks by infant’s biological mother during pregnancy and study infant chronic illness negatively affect the development of PD specific IgG. A balanced maternal diet during pregnancy and a breastfeeding frequency superior to three times per day have a significant positive effect on serum pneumococcal IgG levels among infants.


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