scholarly journals Persisting Salivary IgG against SARS-CoV-2 at 9 Months After Mild COVID-19: A Complementary Approach to Population Surveys

2021 ◽  
Author(s):  
Hassan Alkharaan ◽  
Shaghayegh Bayati ◽  
Cecilia Hellstrom ◽  
Annika Olsson ◽  
Karin Lindahl ◽  
...  
Keyword(s):  
Antibody Testing ◽  
Igg Antibody ◽  
Salivary Iga ◽  
Non Invasive ◽  
Complementary Approach ◽  
History Of ◽  
Specific Igg ◽  
Sparse Methods ◽  
Multiplex Bead

Background: Declining humoral immunity in COVID-19 patients and possibility of reinfections has raised concern. Mucosal immunity particularly salivary antibodies could be short-lived. However, long-term studies are sparse. Methods: Using a multiplex bead-based array platform, we investigated antibodies specific to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins in 256 saliva samples from convalescent patients 1-9 months after symptomatic COVID-19 (n=74, Cohort 1), undiagnosed individuals with self-reported questionnaires (n=147, Cohort 2), and individuals sampled pre-pandemic time (n= 35, Cohort 3). Results: Salivary IgG antibody responses in Cohort 1 (mainly mild COVID-19) were detectable up to 9 month recovery, with high correlations between spike and nucleocapsid specificity. At 9 months, IgG remained in saliva in majority as seen in blood serology. Salivary IgA was rarely detected at this timepoint. In Cohort 2, salivary IgG and IgA responses were significantly associated with recent history of COVID-19 like symptoms. Salivary IgG also tolerated temperature and detergent pre-treatments. Conclusions: Unlike SARS-CoV-2 salivary IgA that appeared short-lived, the specific IgG in saliva appears stable even after mild COVID-19 as noted for blood serology. The non-invasive saliva-based SARS-Cov-2 antibody testing with self-collection at homes may thus serve as a complementary alternative to conventional blood serology.

scholarly journals Regional Difference in Seroprevalence of SARS-CoV-2 in Tokyo: Results from the community point-of-care antibody testing

2020 ◽  
Author(s):  
Morihito Takita ◽  
Tomoko Matsumura ◽  
Kana Yamamoto ◽  
Erika Yamashita ◽  
Kazutaka Hosoda ◽  
...  
Keyword(s):  
Regional Difference ◽  
Point Of Care ◽  
Herd Immunity ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Community Based ◽  
Entire Cohort ◽  
Control And Prevention ◽  
Specific Igg ◽  
Polymerase Chain

AbstractThe serosurvey is an alternative way to know the magnitude of the population infected by coronavirus disease 2019 (COVID-19) since the expansion of capacity of the polymerase chain reaction (PCR) to detect the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was delayed. We herein report seroprevalence of COVID-19 accessed in the two community clinics in Tokyo. The point-of-care immunodiagnostic test was implemented to detect the SARS-CoV-2 specific IgG antibody in the peripheral capillary blood. The overall positive percentage of SARS-CoV-2 IgG antibody is 3.83% (95% confidence interval: 2.76-5.16) for the entire cohort (n =1,071). The central Tokyo of 23 special wards exhibited a significantly higher prevalence compared to the other area of Tokyo (p =0.02, 4.68% [95%CI: 3.08-6.79] versus 1.83 [0.68-3.95] in central and suburban Tokyo, respectively). The seroprevalence of the cohort surveyed in this study is low for herd immunity, which suggests the need for robust disease control and prevention. A community-based approach, rather than state or prefectural levels, is of importance to figure out profiles of the SARS-COV-2 outbreak.

scholarly journals Seroprevalence study of SARS-CoV-2 infection in General Practice in Ireland

BJGP Open ◽  
2021 ◽  
pp. BJGPO.2021.0038
Author(s):  
Michael Edmund O'Callaghan ◽  
Elizabeth Ryan ◽  
Cathal Walsh ◽  
Peter Hayes ◽  
Monica Casey ◽  
...  
Keyword(s):  
General Practice ◽  
Average Length ◽  
Point Of Care ◽  
Antibody Test ◽  
Igg Antibodies ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Seroprevalence Study ◽  
History Of ◽  
Pcr Test

Background: SARS-CoV-2 antibody testing in community settings may help us better understand the immune response to this virus and therefore help guide public health efforts. Aim: Conduct a seroprevalence study of IgG antibodies in Irish GP clinics. Design and Setting: Participants were 172 staff and 799 patients of 15 general practices in the Midwest region of Ireland. Methods: This seroprevalence study utilised 2 manufacturers’ point-of-care (POC) SARS-CoV-2 IgM-IgG combined antibody tests, offered to patients and staff in general practice from mid-June to mid-July 2020. Results: Immunoglobulin G (IgG) seroprevalence was 12.6% in patients attending general practice and 11.1% in staff working in general practice, with administrative staff having the lowest seroprevalence at 2.5% and nursing staff having the highest at 17.6%. Previous symptoms suggestive of SARS-CoV-2 and history of a polymerase chain reaction (PCR) test were associated with higher seroprevalence. IgG antibodies were detected in approximately 80% of participants who had a previous PCR-confirmed infection. Average length of time between participants’ positive PCR test and positive IgG antibody test was 83 days. Conclusion: Patients and healthcare staff in general practice in Ireland had relatively high rates of IgG to SARS-CoV-2 compared to the national average at the time (1.7%). Four-fifths of participants with a history of confirmed COVID-19 disease still had detectable antibodies an average of 12 weeks post-infection. While not proof of immunity, SARS-CoV-2 POC testing can be used to estimate IgG seroprevalence in general practice settings.

scholarly journals Single-Shot Vaccines against Bovine Respiratory Syncytial Virus (BRSV): Comparative Evaluation of Long-Term Protection after Immunization in the Presence of BRSV-Specific Maternal Antibodies

Vaccines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 236
Author(s):  
Jean François Valarcher ◽  
Sara Hägglund ◽  
Katarina Näslund ◽  
Luc Jouneau ◽  
Ester Malmström ◽  
...  
Keyword(s):  
Respiratory Syncytial Virus ◽  
Bovine Respiratory Syncytial Virus ◽  
Single Shot ◽  
Igg Antibody ◽  
Post Vaccination ◽  
Proteomic Data ◽  
Antibody Titers ◽  
Specific Igg ◽  
Syncytial Virus

The induction of long-lasting clinical and virological protection is needed for a successful vaccination program against the bovine respiratory syncytial virus (BRSV). In this study, calves with BRSV-specific maternally derived antibodies were vaccinated once, either with (i) a BRSV pre-fusion protein (PreF) and MontanideTM ISA61 VG (ISA61, n = 6), (ii) BRSV lacking the SH gene (ΔSHrBRSV, n = 6), (iii) a commercial vaccine (CV, n = 6), or were injected with ISA61 alone (n = 6). All calves were challenged with BRSV 92 days later and were euthanized 13 days post-infection. Based on clinical, pathological, and proteomic data, all vaccines appeared safe. Compared to the controls, PreF induced the most significant clinical and virological protection post-challenge, followed by ΔSHrBRSV and CV, whereas the protection of PreF-vaccinated calves was correlated with BRSV-specific serum immunoglobulin (Ig)G antibody responses 84 days post-vaccination, and the IgG antibody titers of ΔSHrBRSV- and CV-vaccinated calves did not differ from the controls on this day. Nevertheless, strong anamnestic BRSV- and PreF-specific IgG responses occurred in calves vaccinated with either of the vaccines, following a BRSV challenge. In conclusion, PreF and ΔSHrBRSV are two efficient one-shot candidate vaccines. By inducing a protection for at least three months, they could potentially improve the control of BRSV in calves.

scholarly journals Alterations in B Cell and Follicular T-Helper Cell Subsets in Patients with Acute COVID-19 and COVID-19 Convalescents

2021 ◽  
Vol 44 (1) ◽  
pp. 194-205
Author(s):  
Igor V. Kudryavtsev ◽  
Natalia A. Arsentieva ◽  
Oleg K. Batsunov ◽  
Zoia R. Korobova ◽  
Irina V. Khamitova ◽  
...  
Keyword(s):  
B Cells ◽  
B Cell ◽  
Humoral Immunity ◽  
N Protein ◽  
Follicular Helper ◽  
Healthy Donors ◽  
Specific Igg ◽  
Sparse Methods

Background. Humoral immunity requires interaction between B cell and T follicular helper cells (Tfh) to produce effective immune response, but the data regarding a role of B cells and Tfh in SARS-CoV-2 defense are still sparse. Methods. Blood samples from patients with acute COVID-19 (n = 64), convalescents patients who had specific IgG to SARS-CoV-2 N-protein (n = 55), and healthy donors with no detectable antibodies to any SARS-CoV-2 proteins (HC, n = 44) were analyses by multicolor flow cytometry. Results. Patients with acute COVID-19 showed decreased levels of memory B cells subsets and increased proportion plasma cell precursors compared to HC and COVID-19 convalescent patients, whereas for the latter the elevated numbers of virgin naïve, Bm2′ and “Bm3+Bm4” was found if compared with HC. During acute COVID-19 CXCR3+CCR6− Tfh1-like cells were decreased and the levels of CXCR3–CCR6+ Tfh17-like were increased then in HC and convalescent patients. Finally, COVID-19 convalescent patients had increased levels of Tfh2-, Tfh17- and DP Tfh-like cells while comparing their amount with HC. Conclusions. Our data indicate that COVID-19 can impact the humoral immunity in the long-term.

scholarly journals Antibody Formation in COVID-19 and Immunisation

2020 ◽  
pp. 1-6
Author(s):  
James Pandarakalam ◽  
James Pandarakalam
Keyword(s):  
T Cells ◽  
The Body ◽  
Human Society ◽  
Jigsaw Puzzle ◽  
Vaccine Production ◽  
Antibody Testing ◽  
History Of ◽  
Sudden Appearance ◽  
Existential Problem

Antibody testing is vital in the study of the dangerousness, spread, identification of high-risk individuals and vaccine production against SARS-CoV-2. Viruses leave trails in the infected body and the immunologists turn out to be the detectives examining these viral footprints. There are two major types of tracks or memory responses that can be utilized by the body against reinfection: B cells which produce antibodies and T cells organising responses through cytotoxic cells and restricting viral replication. T cells’ memory of SARS-CoV-2 appears to last longer than antibodies and immunisation can activate T cells as well if it fails to induce long term antibody production. The immune history of SARS-CoV-2 is a huge jigsaw puzzle; several pieces are still missing. This viral research has met with a shortage of valuable foundational knowledge because of the sudden appearance of the virus and its spread. COVID-19 has posed an existential problem for the whole of human society.

scholarly journals Potential False-Positive and False-Negative Results for COVID-19 IgG/IgM Antibody Testing After Heat-Inactivation

2021 ◽  
Vol 7 ◽  
Author(s):  
Jie Lin ◽  
Wei Dai ◽  
Weiwei Li ◽  
Li Xiao ◽  
Tao Luo ◽  
...  
Keyword(s):  
False Negative ◽  
Antibody Detection ◽  
Heat Inactivation ◽  
Antibody Testing ◽  
Igg Antibody ◽  
Igm Antibody ◽  
Negative Results ◽  
False Negative Results ◽  
Specific Igg ◽  
Potential False Positive

Objectives: With the worldwide spread of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), various antibody detection kits have been developed to test for SARS-CoV-2– specific IgG, IgM, and total antibody. However, the use of different testing methods under various heat-inactivation conditions might affect the COVID-19 detection results.Methods: Seven different antibody detection kits produced by four manufacturers for detection of SARS-CoV-2 IgG, IgM, and total antibody were tested at Wuhan Huoshenshan Hospital, China. Most of the kits used the indirect immunity, capture, and double-antigen sandwich methods. The effects of various heat-inactivation conditions on SARS-CoV-2-specific IgG, IgM, and total antibody detection were analyzed for the different test methods.Results: Using the indirect immunity method, values for SARS-CoV-2 IgG antibody significantly increased and those for IgM antibody decreased with increasing temperature of heat-inactivation using indirect immunity method. However, values for SARS-CoV-2 IgM and total antibody showed no change when the capture and double-antigen sandwich methods were used. The changes in IgG and IgM antibody values with the indirect immunity method indicated that heat-inactivation could affect COVID-19 detection results obtained using this method. In particular, 18 (22.2%) SARS-CoV-2 IgM positive samples were detected as negative with heat-inactivation at 65°C for 30 min, and one (25%) IgG negative sample was detected as positive after heat-inactivation at 56°C for 60 min and 60°C for 30 min.Conclusions: Heat-inactivation could increase SARS-CoV-2 IgG antibody values, and decrease IgM antibody values, causing potential false-positive or false-negative results for COVID-19 antibody detection using the indirect immunity method. Thus, before conducting antibody testing, the testing platforms should be evaluated in accordance with the relevant requirements to ensure accurate COVID-19 detection results.

scholarly journals Salivary antibodies following parenteral immunization of infants with a meningococcal serogroup A and C conjugated vaccine

1999 ◽  
Vol 123 (2) ◽  
pp. 201-208 ◽  
Author(s):  
R. BORROW ◽  
A. J. FOX ◽  
K. CARTWRIGHT ◽  
N. T. BEGG ◽  
D. M. JONES
Keyword(s):  
Geometric Mean ◽  
Herd Immunity ◽  
Epidemiological Studies ◽  
Nasopharyngeal Carriage ◽  
Antibody Testing ◽  
Conjugate Vaccines ◽  
Salivary Iga ◽  
Non Invasive ◽  
Parenteral Immunization

Bacterial and viral salivary antibody testing is proving sensitive and specific, useful for epidemiological studies, and is simple and non-invasive. Salivary serogroup C polysaccharide-specific (SC PS-S) IgA and IgG were determined as a proportion of total salivary IgA and IgG in a group of UK infants who were recipients of a conjugated A/C meningococcal PS vaccine. Geometric mean concentrations (GMCs) of salivary SC PS-S IgG per mg of total IgG (μg/mg) were 0·1 pre-vaccination, rising to 8·2 post first, 16·1 post second and 29·3 post third dose of vaccine. For IgA, the corresponding GMCs in ng/mg were 0·1, 82·8, 69·6 and 91·2. Significant correlations (P<0·0001) were found between serum Ig and salivary IgG SC PS-S antibody for pre-vaccine and 1 month post each dose of vaccine suggesting that SC PS-S IgG in saliva was largely derived from serum. Of the five infants whose sera were analysed for isotype-specific responses, only traces of IgM and IgA were measurable suggesting that the SC PS-S IgA was locally produced. These findings suggests that the widespread use of meningococcal conjugate vaccines is likely to reduce nasopharyngeal carriage and may thereby induce herd immunity in the vaccinated population.

scholarly journals Сentral serous chorioretinopathy and vitelliform dystrophies occurring in adults: predictors of differential diagnosis

2021 ◽  
Vol 14 (1) ◽  
pp. 51-61
Author(s):  
Nataliia V. Matcko ◽  
Marina V. Gatsu
Keyword(s):  
Differential Diagnosis ◽  
Family History ◽  
Predictive Value ◽  
Positive Family History ◽  
Non Invasive ◽  
Recognition Quality ◽  
Area Under Roc Curve ◽  
History Of ◽  
Ophthalmologic Examination

AIM: To study predictors in order to optimize the differential diagnosis of persistent central serous chorioretinopathy (CSCR) and different forms of vitelliform dystrophies occurring in adults. MATERIALS AND METHODS: Ninety eyes of 61 patients with long-term serous retinal detachments were recruited in study. All patients underwent ophthalmologic examination including family history, best corrected visual acuity, biomicroscopy, and multimodal imaging including fundus photo, SD-OCT, OCT-A, BAF, FA, ICGA. After the studies, the patients were divided into two groups: with vitelliform dystrophies 30 eyes of 30 patients and with CSCR 31 eyes of 31 patients. Diagnostic predictors found in both groups were scrutinized, mathematical models were obtained, and their recognition quality was assessed by the area under ROC curve. The criteria for all types of research were studied and the predictive value was assessed with the use of ROC analysis. RESULTS: The most informative non-invasive predictors for the diagnosis of vitelliform dystrophies occurring in adults are the following: a positive family history of the disease, brightness and gradient of hyperautofluorescence (hyperAF), typical hyperAF in the form of a crescent and beads, the presence of massive subretinal deposits and deposits in the form of stalactites. The most informative non-invasive predictors for the diagnosis of persistent CSCR are the following: additional hypoAF or hyperAF points or areas outside the main focus, hyperreflective dots in the neurosensory retina and an increase in choroidal thickness, irregular pigment epithelial detachments, presence of CNV. The highest predictive value for both groups was determined for BAF studies. CONCLUSIONS: The results obtained make it possible to optimize the differential diagnosis of persistent CSCR and different forms of vitelliform dystrophies occurring in adults.

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