IgG Test Research Articles

Persistence of immunity against Omicron BA.1 and BA.2 variants following homologous and heterologous COVID-19 booster vaccines in healthy adults after a two-dose AZD1222 vaccination

ObjectivesThe SARS-CoV-2 Omicron variant presents numerous mutations potentially able to evade neutralizing antibodies (NAbs) elicited by COVID-19 vaccines. Therefore, this study aimed to provide evidence on a heterologous booster strategy to overcome the waning immunity against Omicron variants. MethodsParticipants who completed the Oxford/AstraZeneca (hereafter AZD1222) vaccine dose for 5-7 months were enrolled. The reactogenicity and persistence of immunogenicity in both humoral and cellular response after a homologous or heterologous booster with the AZD1222 and messenger RNA (mRNA) vaccines (BNT162b2, full, or half-dose mRNA-1273) administered 6 months after primary vaccination were determined. ResultsA total of 229 individuals enrolled, and waning of immunity was observed 5-7 months after the AZD1222-primed vaccinations. Total receptor-binding domain (RBD) immunoglobulin (Ig) levels, anti-RBD IgG, and focus reduction neutralization test against Omicron BA.1 and BA.2 variants and T cell response peaked at 14-28 days after booster vaccination. Both the full and half dose of mRNA-1273 induced the highest response, followed by BNT162b2 and AZD1222. At 90 days, the persistence of immunogenicity was observed among all mRNA-boosted individuals. Adverse events were acceptable for all vaccines. ConclusionA heterologous mRNA booster provided a significantly superior boost of binding and NAbs levels against the Omicron variant compared with a homologous booster in individuals with AZD1222-primed vaccinations.

SARS-CoV-2 Seroprevalence among Healthcare Workers after the First and Second Pandemic Waves.

Background: The Grand Hôpital de Charleroi is a large non-academic Belgian hospital that treated a large number of COVID-19 inpatients. In the context of this pandemic, all professions-combined healthcare workers (HCWs), and not only direct caregivers, are a frontline workforce in contact with suspected and confirmed COVID-19 cases and seem to be a high-risk group for exposure. The aim of our study was to estimate the prevalence of anti-SARS-CoV-2 antibodies in HCWs in our hospital after the first and second pandemic waves and to characterize the distribution of this seroprevalence in relation to various criteria. Methods: At the end of the two recruitment periods, a total of 4008 serological tests were performed in this single-center cross-sectional study. After completing a questionnaire including demographic and personal data, possible previous COVID-19 diagnostic test results and/or the presence of symptoms potentially related to COVID-19, the study participants underwent blood sampling and serological testing using DiaSorin’s LIAISON® SARS-CoV-2 S1/S2 IgG test for the first phase and LIAISON® SARS-CoV-2 TrimericS IgG test for the second phase of this study. Results: In total, 302 study participants (10.72%) in the first round of the study and 404 (33.92%) in the second round were positive for SARS-CoV-2-IgG antibodies. The prevalence of seropositivity observed after the second wave was 3.16 times higher than after the first wave. We confirmed that direct, prolonged, and repeated contact with patients or their environment was a predominant seroconversion factor, but more unexpectedly, that this was the case for all HCWs and not only caregivers. Finally, the notion of high-risk contact seemed more readily identifiable in one’s workplace than in one’s private life. Conclusions: Our study confirmed that HCWs are at a significantly higher risk of contracting COVID-19 than the general population, and suggests that repeated contacts with at-risk patients, regardless of the HCWs’ professions, represents the most important risk factor for seroconversion (Clinicaltrials.gov number, NCT04723290).

Machine learning to support visual auditing of home-based lateral flow immunoassay self-test results for SARS-CoV-2 antibodies

BackgroundLateral flow immunoassays (LFIAs) are being used worldwide for COVID-19 mass testing and antibody prevalence studies. Relatively simple to use and low cost, these tests can be self-administered at home, but rely on subjective interpretation of a test line by eye, risking false positives and false negatives. Here, we report on the development of ALFA (Automated Lateral Flow Analysis) to improve reported sensitivity and specificity.MethodsOur computational pipeline uses machine learning, computer vision techniques and signal processing algorithms to analyse images of the Fortress LFIA SARS-CoV-2 antibody self-test, and subsequently classify results as invalid, IgG negative and IgG positive. A large image library of 595,339 participant-submitted test photographs was created as part of the REACT-2 community SARS-CoV-2 antibody prevalence study in England, UK. Alongside ALFA, we developed an analysis toolkit which could also detect device blood leakage issues.ResultsAutomated analysis showed substantial agreement with human experts (Cohen’s kappa 0.90–0.97) and performed consistently better than study participants, particularly for weak positive IgG results. Specificity (98.7–99.4%) and sensitivity (90.1–97.1%) were high compared with visual interpretation by human experts (ranges due to the varying prevalence of weak positive IgG tests in datasets).ConclusionsGiven the potential for LFIAs to be used at scale in the COVID-19 response (for both antibody and antigen testing), even a small improvement in the accuracy of the algorithms could impact the lives of millions of people by reducing the risk of false-positive and false-negative result read-outs by members of the public. Our findings support the use of machine learning-enabled automated reading of at-home antibody lateral flow tests as a tool for improved accuracy for population-level community surveillance.

SARS-CoV-2 reinfection across a spectrum of immunological states.

PurposeSeveral cases of symptomatic reinfection with severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) after full recovery from a prior episode have been reported. As reinfection has become an increasingly common phenomenon, an improved understanding of the risk factors for reinfection and the character and duration of the serological responses to infection and vaccination is critical for managing the coronavirus disease 2019 (COVID‐19) pandemic.MethodsWe described four cases of SARS‐CoV‐2 reinfection in individuals representing a spectrum of healthy and immunocompromised states, including (1) a healthy 41‐year‐old pediatrician, (2) an immunocompromised 31‐year‐old with granulomatosis with polyangiitis, (3) a healthy 26‐year‐old pregnant woman, and (4) a 50‐year‐old with hypertension and hyperlipidemia. We performed confirmatory quantitative reverse transcription‐polymerase chain reaction and qualitative immunoglobulin M and quantitative IgG testing on all available patient samples to confirm the presence of infection and serological response to infection.ResultsOur analysis showed that patients 1 and 2, a healthy and an immunocompromised patient, both failed to mount a robust serologic response to the initial infection. In contrast, patients 3 and 4, with minimal comorbid disease, both mounted a strong serological response to their initial infection, but were still susceptible to reinfection.ConclusionRepeat episodes of COVID‐19 are capable of occurring in patients regardless of the presence of known risk factors for infection or level of serological response to infection, although this did not trigger critical illness in any instance.

Immunological markers of the development of bronchial asthma under conditions of contamination by bio-mediated technogenic chemical factors in children

Introduction. The issue of sanitary safety of the population under the conditions of chronic exposure to environmental anthropogenic chemical factors, which play an etiological and pathogenetic role in the formation of non-communicable diseases, especially in the occurrence of bronchial asthma (BA) in children, is currently becoming particularly relevant. Materials and methods. Sixty six institutions located near major highways were examined. Of these, the observation group consisted of 21 children whose content of manganese, chromium and formaldehyde in biological media significantly exceeded background values (p<0.05). The comparison group consisted of 45 children with the content of haptens in biological media at the level of background indicators. The analysis of biological media for the content of chemical allergens by mass spectrometry, formaldehyde was made with high-performance liquid chromatography (HPLC). The study of the immune status of the examined cases included the use of flow cytometry (CD3, CD4, CD25, CD95), enzyme immunoassay (leukotrienes, IL1ß, IL4, IL6, IL8, IL10, INFu, TNFa, IgE total), the Mancini method (radial immunodiffusion) (IgM, IgG, IgA) and allergosorbent testing (specific to allergen metals and formaldehyde IgE). Results. A comparative analysis of the immune and allergological status of the subjects revealed children with atopic bronchial asthma, characterized by excessive contamination with bio-mediated haptens, to show a significant increase in total and formaldehyde- and chromium-specific IgE, leukotrienes, as well as lymphocytes expressing CD25 and CD95 molecules (p<0.05) and a decrease in cytokine expression. Limitations. There were no restrictions on the conduct of research related to reagents and instrumentation. Conclusion. As a result of the performed studies, there were substantiated immunological markers of the effect, reflecting the modification of the immunological response of children with asthma in conditions of elevated contamination of the biological media with chromium, manganese and formaldehyde, which have an adjuvant effect on the body, forming the features of immunological manifestations of asthma (for example, the city of Perm).

Determination of Helicobacter Pylori Infection Prevalence by Non-invasive Methods

Background: Helicobacter pylori (H. pylori) is identified as the most frequent agent of bacterial infections in humans which can cause various gastrointestinal diseases. This pathogen has infected approximately half of the world’s population, and its outbreak has varied across different regions. The purpose of this study was to estimate the H. pylori infection prevalence amongst patients in Fardis county, Alborz province, Iran, using noninvasive methods. Methods: A total of 5677 patients were analyzed from September 2020 to October 2021 to detect H. pylori by the use of enzyme-linked immunosorbent assay (ELISA) IgG, IgA, and IgM tests, stool antigen test (SAT), and urea breath test (UBT). Results: Of 5677 patients, 3486 (61.4%) were female and 2191 (38.6%) were male with the mean age of 38.82 ± 18.289 years old. The overall rate of H. pylori infection positive was 31.46%, and the serological tests were the most prescribed types of tests. The IgG test and then SAT detected the most positive cases. Further, the infection rate was significantly associated with age. Except for the case of IgM, which was higher in females compared to males, no significant difference was found between gender and bacteria outbreak. Conclusions: This study indicated a decline in H. pylori infection prevalence compared with the prior survey conducted at this center. However, its rate amongst the patients referring to Fardis laboratory is still high.

ERITEMA MULTIFORME TERKAIT INFEKSI VIRUS DAN ALERGI: LAPORAN KASUS

Introduction : Erythema Multiforme (EM) is an acute mucocutaneous inflammatory disease that is self-limiting and manifests itself on the skin, oral mucosa, and another mucosa. Erythema multiforme caused by Herpes Simplex Virus (HSV) infection was diagnosed as Herpes Associated Erythema Multiforme (HAEM). Case and Management : We report a case of EM in a male patient aged 23 years, with a serosanguinous crustal lesion, tend to bleed lips, as well as lesions multiple erosive on the labial mucosa. The patient had a history of fever and symptoms of the prodrome before the lesions appeared, pain when eating and drinking if the lesions appeared. The laboratory test results showed Total IgE: 713.0, IgG HSV1: Positive 100.7, and IgM HSV1: Negative 14.1. Based on the results of the history and clinical examination as well as supporting (IgG and IgE serological tests) a diagnosis of Herpes Associated Erythema Multiforme was made. Treatment with topical corticosteroids, antiseptic mouthwash, multivitamins, and petroleum jelly cream, showed significant improvement and reduction in clinical signs and symptoms in the first week of treatment. Conclusion : The combination of pharmacological and non-pharmacological treatment plays an important role in the advancement of HAEM treatment.

Trunk-dominant and classic facial pemphigus foliaceus in dogs - comparison of anti-desmocollin-1 and anti-desmoglein-1 autoantibodies and clinical presentations.

Canine trunk-dominant pemphigus foliaceus (PF) is mentioned rarely in the literature. The goal of this study was to provide clinical description of trunk-dominant PF and to demonstrate the prevalence of serum antikeratinocyte, anti-desmocollin-1 (DSC1) and anti-desmoglein-1 (DSG1) antibodies, and determine their diagnostic value in this particular PF phenotype. Clinically relevant information was collected from 31, 25 and 34 dogs with trunk-dominant and facial PF and superficial pyoderma (SP), respectively. Sera from these dogs were tested for antikeratinocyte, anti-DSC1 and anti-DSG1 antibodies using indirect immunofluorescence on canine tissues and DSC1- and DSG1-transfected cells. Sera from healthy dogs and dogs with clinically irrelevant diseases served as controls. Footpad involvement and grouped/polycyclic lesion organisation were identified as features of both PF phenotypes, and not of SP. Antikeratinocyte immunoglobulin (Ig)G was not specific for canine PF. By contrast, antigen-specific IgG was detected only in PF sera; anti-DSC1 IgG in 100% and 58% of dogs with facial and trunk-dominant PF, respectively, and anti-DSG1 IgG in 7% of dogs with trunk-dominant PF only. Trunk-dominant PF shares DSC1 as a major autoantigen with facial PF. The ability to detect anti-DSC1 IgG is lower in trunk-dominant PF, yet despite the lower sensitivity, the positive predictive value and accuracy of this particular anti-DSC1 IgG test are high. A negative test result, however, cannot exclude the diagnosis, and characteristic clinical features such as footpad involvement and/or grouped/polycyclic lesions must be considered when distinguishing trunk-dominant PF from its most relevant differential diagnosis: SP.

Effects of Obstructive Sleep Apnea on SARS-CoV-2 Antibody Response After Vaccination Against COVID-19 in Older Adults.

IntroductionPrevious studies have linked sleep disturbances (including sleep deprivation and obstructive sleep apnea) to an impairment in immune response after vaccination for several diseases, although it has not yet been tested for COVID-19. This study sought to evaluate the effects of obstructive sleep apnea on anti-SARS-CoV-2 IgG levels after vaccination against COVID-19 among older adults.MethodsThe study was based on a convenience sample of inpatients who underwent full night type-I polysomnography. Inclusion criteria included being ≥60 years with full COVID-19 vaccination schedule. Exclusion criteria included previous COVID-19 diagnosis (assessed via self-report), less than 15 days between last dose and IgG testing, self-report of continuous positive air pressure (CPAP) use in the last three months, having undergone CPAP or split-night polysomnography, or incomplete/invalid data.ResultsOut of 122 included patients (no/mild OSA: 35; moderate: 31; severe: 56), 9.8% were considered seronegative for the IgG anti-SARS-CoV-2 test (IgG count<50.0 AU/mL), and the median IgG levels for the whole sample was 273 AU/mL (IQR: 744), with no statistically significant differences among OSA severity groups. There was neither association between OSA severity and IgG serostatus nor correlation between IgG levels and apnea-hypopnea index. A linear regression model to predict IgG levels was built, produced an R2 value of 0.066 and the only significant predictor was time from vaccination to testing; while OSA severity was considered non-significant.DiscussionOur results demonstrate that the severity of OSA is not correlated with a decrease in anti-SARS-CoV-2 IgG levels among older adults, and that the efficiency of COVID-19 vaccinations are not reduced from mild to severe OSA.

Immunogenicity of the vaccine against Sars-Cov-2 in cancer patients under active treatment.

e13632 Background: Coranavirus disease 2019 (COVID-19) has affected more than 220 millon people worldwide. The establishment of safe and effective vaccine coverage is crucial in these patients. We aim to investigate the safety, adverse effects and immune response (cellular and humoral) in cancer patients under active treatment and risk criteria. Methods: 56 samples from cancer patients under active treatment for cancer were collected before and after vaccination Demographic, clinical and biochemical data were collected and a post-vaccination symptomatology questionnaire was performed. For the determination of anti-SARS-Cov-2 antibodies (Immunoglobulin G and immunoglobulin M) we used the ELISA technique (LIASON SARS-CoV-2 S1/S2 IgG test and LIASON SARS-CoV-2 IgM test, DiaSorin, Saluggia, Italy). A study of the lymphocyte population was performed by flow cytometry. Results: We enrolled 52 patients with cancer who received mRNA vaccines (mRNA-1273 and BNT162b2), 2 patients with AZD1222vaccine and 2 with Ad26.COV2.S vaccine. All patients were SARS-COV-2 naive as determined by a negative anti-SARS-COVID-2 IgG test baseline. The median follow-up time was 50 days after receip of a second vaccine dosis. All subject received anti- cancer therapy. The most common anti-cancer treatment received by this cohort of patients was cytotoxic chemoterapy (44.6%), immunotherapy (25%), and monoclonal antibody therapy (14.3%). Overall, a high rate of seroconvertion(anti–IgG) (94,5%) was observed in our cohort, 1 patients with chemotherapy (1,8%) and 2 patients with immunotherapy (3,6%) were negatives. No significant differences in antibody titer were observed according to therapy. Thirty percent presented an antibody titer lower than 1000 U/ml, 27 (48%) patients developed an anti-SARS-CoV2 titer between 1000-4000 U/ml, and only 9 (16%) subjects presented a titer higher than 4000 U/ml. Studies of the lymphocyte profile of vaccinated patients showed no significant changes in the subtypes, except for peripheral memory CD3+ CD8+ lymphocytes which were significantly increased (p = 0.0001) after the second dose of anti-SARS-CoV-2 vaccine. Interestingly, cell apoptosis was significantly reduced in almost all T lymphocyte subtypes studied in vaccinated patients. Finally, analysis of blood cells showed a statistically significant increase (p = 0.0402) of eosinophils in vaccinated patients compared to baseline data. Conclusions: A personalized approach to vaccination can be proposed to cancer patients, especially depending on the type of tumor and the specific oncological treatments received. We are currently recruiting patients (n = 150) who have received the third dose of vaccine and plan to follow up at 6 months for humoral and cellular immune response. Final results will be reported at the ASCO meeting.

Seropositivity to SARS-CoV-2 in Alberta, Canada in a post-vaccination period (March 2021–July 2021)

Background The COVID-19 pandemic has necessitated the need to rapidly make public health decisions. We systematically evaluated SARS-CoV-2 seropositivity to understand local COVID-19 epidemiology and support evidence-based public health decision making. Methods Residual blood samples were collected for SARS-CoV-2 receptor binding domain (RBD) IgG testing over a 1–5 day period monthly from 26 February 2021–9 July 2021 from six clinical laboratories across the province of Alberta, Canada. Monthly crude and adjusted (for age and gender) seropositivity were calculated. Results were linked to provincial administrative, laboratory, and vaccine databases. Results 60,632 individual blood samples were tested. Vaccination data were available for 98.8% of samples. Adjusted RBD IgG positivity rose from 11.9% (95% confidence interval [CI] 11.9–12.0%) in March 2021 to 70.2% (95% CI 70.2–70.3%) in July 2021 (p < .0001). Seropositivity rose from 9.4% (95% CI 9.3–9.4%) in March 2021 to 20.2% (95% CI 20.1–20.2%) in July 2021 in unvaccinated Albertans. Unvaccinated seropositive individuals were from geographic areas with significantly (p < .001) lower median household income, lower proportion of married/common-law relationships, larger average household size and higher proportions of visible minorities compared to seronegative unvaccinated individuals. In July 2021, the age groups with the lowest and highest seropositivity in unvaccinated Albertans were those ≥80 years (12.0%, 95% CI 5.3–18.6%) and 20–29 years (24.2%, 95% CI 19.6–28.8%), respectively. Of seropositive unvaccinated individuals, 50.2% (95% CI 45.9–54.5%) had no record of prior SARS-CoV-2 molecular testing. Conclusions Longitudinal surveillance of SARS-CoV-2 seropositivity with data linkage is valuable for decision-making during the pandemic.

Assessment of index value performance of enzyme immunoassay test in predicting the diagnosis of human brucellosis.

Clinical presentation of brucellosis is variable. Therefore, it must be confirmed with laboratory findings. Standard tube agglutination test (STAT) is commonly used for diagnosis of brucellosis. ELISA tests differentiate between IgM and IgG antibodies. However, there are evidences revealing that they do not have sufficient specificity. This study aimed to determine an ELISA optimal index value in the diagnosis of brucellosis. Brucella STAT and ELISA IgM/IgG tests of patients admitted to the hospital with signs and symptoms of brucellosis between January 2017 and December 2019 were evaluated in the Microbiology Laboratory. ELISA IgM and IgG serum median index value was significantly higher in STAT positive (1 ≥ 1:160) group (p < 0.001 for both). By ROC analysis of 117 patients, when the IgM index value was determined to be 2.44, the sensitivity, specificity, positive and negative predictive values were 85.7%, 71.4%, 60%, and 90.9%, respectively, and when the IgG index 7.85 was determined, these values were 85.7%, 53.7%, 36.7%, and 92.3%, respectively was detected. In this study, it was revealed that Vircell Brucella had a good clinical diagnostic performance for index value of 2.44 for IgM test kit and 7.95 for IgG test kit. If the diagnosis of brucellosis is correctly predicted with index values in Brucella IgM and IgG tests before STAT analysis, they can be used in the process of clinical decision. In addition to the results of Brucella ELISA, reporting index values and determining optimal index values for each laboratory can help the diagnosis of brucellosis.

A cardiac hydatid cyst; four years of postoperative follow up

Hydatid disease is a parasitic disease that mainly involves liver and lung tissues. Isolated cardiac involvement is very rare. We report a 40-year-old woman who presented in our emergency department for non-specific chest pain. She had no prior history of a hydatid disease Her transthoracic echocardiography illustrated a cystic mass in the right ventricular apex. Her contrast-enhanced computed tomographic scan of the chest showed a complex cystic lesion in the right ventricular wall at region of apex with enhancing thin wall and internal septations. Her immunological IgG test was positive for Echinococcosis. No other hydatid cysts were seen in the other organs such as liver and lungs by ultrasound scan of abdomen and computer tomography scan of chest respectively. After a week course of Albendazole, 400mg twice a day, she underwent cystectomy with cappitonage surgery under cardiopulmonary bypass. The patient was discharged from the hospital after an uneventful postoperative recovery. Echocardiographic and cardiac contrast enhanced computer tomography (CECT) evaluation in fourth year of follow-up revealed no evidence of recurrence of hydatids and ventricular function remained normal.

Comparison of Four Systems for SARS-CoV-2 Antibody at Three Time Points after SARS-CoV-2 Vaccination.

Background: Immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wanes over time after vaccination. Methods: We compared SARS-CoV-2 antibody levels in serial samples from 350 vaccinated individuals at 3 time points (3 weeks after the first or second dose and before the third dose) with 4 assays: GenScript cPASS SARS-CoV-2 neutralization antibody detection kits (cPASS), Siemens SARS-CoV-2 IgG (sCOVG), Abbott SARS-CoV-2 IgG II Quant (CoV-2 IgG II), and an Immuno-On™ COVID-19 IgG test (Immuno-On IgG). Antibody levels by time, concordance between assays, and values from other tests corresponding to the percent inhibition results in cPASS were assessed. Results: The median values at three time points were 49.31%, 90.87%, and 53.38% inhibition for cPASS, 5.39, 13.65, and 2.24 U/mL for sCOVG, 570.25, 1279.65, and 315.80 AU/mL for CoV-2 IgG II, and 223.22, 362.20, and 62.20 relative units (RU) for Immuno-On IgG. The concordance with cPASS at each time point ranged from 0.735 to 0.984, showing the highest concordance in the second sample and lowest concordance in the third in all comparative tests. The values corresponded to 30% inhibition, and the cutoffs of cPASS, were 2.02 U/mL, 258.6 AU/mL, and 74.2 RU for each test. Those for 50%, 70%, and 90% inhibition were 3.16, 5.66, and 8.26 U/mL for sCOVG, while they were 412.5, 596.9, and 1121.6 AU/mL for CoV-2 IgG II and 141.8, 248.92, and 327.14 RU for Immuno-On IgG. Conclusions: This study demonstrated the dynamic changes in antibody values at different time points using four test systems and is expected to provide useful baseline data for comparative studies and standardization efforts in the future.

Robust antibody response after a third BNT162b2 vaccine compared to the second among immunocompromised and healthy individuals, a prospective longitudinal cohort study

PurposeAs protection from COVID-19 following two doses of the BNT162b2 vaccine showed a time dependent waning, a third (booster) dose was administrated. This study aims to compare the antibody response following the third dose versus the second and to evaluate post-booster seroconversion. MethodsA prospective observational study conducted in Maccabi Healthcare Services. Serial SARS-CoV-2 Spike IgG tests, 1,2,3 and 6 months following the second vaccine dose and one month following the third were obtained. Neutralizing antibody levels were measured in a subset of participants. Per individual SARS-CoV-2 Spike IgG titer ratios were calculated one month after the booster administration compared to titers one month following the second dose and prior to booster. ResultsAmong 110 participants,56 (51%) were women. Mean age was 61.7 ± 1.9 years and 66 (60%) were immunocompromised. One month after third dose, IgG titers were induced 7.83 (95 %CI 5.25–11.67) folds and 2.40 (95 %CI 1.90–3.03) folds compared to one month after the second, in the immunocompromised and immunocompetent groups, respectively. Of the 17 immunocompromised participants who were seronegative after the second dose, 4 (24%) became seropositive following the third. Comparing the titers prior to the third dose, an increase of 50.7 (95 %CI 32.5–79.1) fold in the immunocompromised group and 25.7 (95 %CI 19.1–34.7) fold in and immunocompetent group, was observed. ConclusionA third BNT162b2 vaccine elicited robust humoral response, superior to the response observed following the second, among immunocompetent and immunocompromised individuals.

0707 Effects of obstructive sleep apnea on Anti-SARS-COV-2 igg levels in older adults vaccinated against covid-19

Abstract Introduction Sleep disorders and sleep deprivation induces decreased antibody response following vaccination for different viral diseases (including H1N1, influenza and hepatitis A). The same has been speculated for COVID-19. This study aimed to assess whether obstructive sleep apnea (OSA) reduces antibody levels after COVID-19 vaccination among older adults. Methods This was a convenience-sample study composed of older adults (≥60 years old). Those who underwent polysomnography at the Sleep Institute (São Paulo, Brazil) and received complete COVID-19 vaccination schedule were considered eligible. Individuals with previous diagnosis of COVID-19, less than 15 days between vaccination and IgG testing, or CPAP use in the last 3 months were excluded. Anti-SARS-CoV-2 IgG levels were measured using a chemiluminescence assay. The participants were distributed in the following groups, according to their apnea-hypopnea index (AHI): no/mild OSA (AHI&amp;lt;15), moderate OSA (AHI≥15 and &amp;lt;30) and severe OSA (AHI≥30). The effects of OSA on IgG levels (ANOVA), the correlation between IgG levels and AHI (Spearman’s correlation test) and the association between serostatus (positive vs. negative) and OSA severity levels (X2 test) were analysed. Results were considered as statistically significant when p&amp;lt;0.05. Results The sample included 122 older adults (median age 72.0 - IQR: 5.7), of whom 35 (28.6%) had AHI no/mild OSA; 31 (25.4%) had moderate OSA, and 56 (45.9%) had severe OSA. Oxford/AstraZeneca was the most referred vaccine (n=111, 91.0%), followed by CoronaVac (n=9, 9.0%). Seropositive status (IgG count ≥50.0 AU/mL) was observed in 90.2% of the participants and the median IgG levels in the complete sample was 273.0 AU/ML (IQR: 744.0). No/mild, moderate and severe OSA groups presented IgG levels of 482.0 (IQR: 677.0), 285 (IQR: 884.0) and 181.0 (IQR: 598.0), respectively, with no statistical difference them (p=0.606). There was no statistically significant correlation between AHI index and IgG levels (Spearman’s rho=-0.169, p=0.063) and no significant association between serostatus and OSA severity groups (X2=0.912; p=0.634). Conclusion Anti-SARS-CoV-2 IgG levels after vaccination are not significantly affected by OSA among older adults. Thus, despite being at higher risk for severe cases, OSA does not decrease the antibody response following vaccination against COVID-19. Support (If Any) AFIP, CNPq, CAPES

Seroprevalence of toxoplasmosis in quail birds (Coturnix coturnix) in Baghdad City, Iraq

Toxoplasmosis is a common zoonotic parasitic disease in humans and animals worldwide, caused by the protozoan parasite Toxoplasma gondii. The study designed for detection the prevalence rate of Toxoplasmosis in quail birds (Coturnix coturnix) from different areas in Baghdad city, Iraq (Al- Ghazel souq, Al-Malhani, Al-Hurria, Al Shoula’a and quails farms in Abu-Ghraib Poultry Research Station) by indirect ELISA IgG test and determined the effects of some risk factors (sex, age, areas and months) on this rate during the period from the 1st January 2021, to 30th September 2021. One hundred and fifty sera of quails (75) hens and &#x0D; (75) cocks were examined by indirect IgG Enzyme Linked Immunosorbent Assay (ELISA). The results clarified the total infection rate was 19.33% (29/150) in quails 24% (18/75) hens and 14.66% (11/75) cocks. The higher infection rate 24% (24/100) was recorded in the age group ≤ Maturity period (35 days) ≤ Year (1-2ys), while a lower infection rate 10% (5/50) was found in the age group &lt; Maturity period (35 days). A higher infection rate 41.17% (7/17) was recorded in September, and lower infection rate 5.88% (1/17) was recorded in July.

FC086: Improved Immunologic Response to COVID-19 Vaccine with Prolonged Dosing Interval in Hemodialysis Patients

BACKGROUND AND AIMSVaccination against coronavirus disease 2019 (COVID-19) can reduce disease incidence and severity. Dialysis patients demonstrate a delayed immunologic response to vaccines. We determined factors affecting the immunologic response to COVID-19 vaccines in hemodialysis patients.METHODAll patients within a Swedish hemodialysis network, vaccinated with two doses of COVID-19 vaccine 2–8 weeks before inclusion, were eligible for this cross-sectional study. Severe adult respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein antibody levels were determined by the EliA SARS-CoV-2-Sp1 IgG test (Thermo Fisher Scientific, Phadia AB) and related to clinical and demographic parameters. Eighty-nine patients were included.RESULTSPatients were vaccinated with two doses of Comirnaty (BNT162b2, 73%) or Spikevax (mRNA-1273, 23.6%). Three patients received combinations of different vaccines. Response rate (antibody titres >7 U/mL) was 89.9%, while 39.3% developed high antibody titres (>204 U/mL), 47 (43–50) days after the second dose. A previous COVID-19 infection associated with higher antibody titres [median (25th–75th percentile) 1558.5 (814.5–3763.8) U/mL versus 87 (26–268) U/mL; P = 0.002], while the time between vaccine doses did not differ between groups (P = 0.7). Increasing SARS-CoV-2 antibody titres were independently associated with increasing time between vaccine doses, decreasing serum calcium levels and previous COVID-19 (Table 1).CONCLUSIONIn conclusion, a longer interval between COVID-19 mRNA vaccine doses, lower calcium and a previous COVID-19 infection were independently associated with a stronger immunologic vaccination response in hemodialysis patients. While the response rate was good, only a minority developed high antibody titres 47 (43–50) days after the second vaccine dose.Table 1.Multiple regression of predictors of SARS-CoV-2 spike IgG response to COVID-19 vaccinesRegression coefficient(95% CI)P(Constant)0.015 (–0.507 to 0.537)0.95Type of vaccine–0.194 (–0.566 to 0.179)0.30Sodium (1 SD)–0.154 (–0.309 to 0.001)0.051Calcium (1 SD)–0.233 (–0.4 to –0.067)0.007Treatment time (1 SD)–0.05 (–0.234 to 0.133)0.586Bodymass index (1 SD)0.104 (–0.086 to 0.294)0.279IDBWG (1 SD)0.118 (–0.042 to 0.278)0.145Kt/V (1 SD)0.009 (–0.159 to 0.177)0.915Vaccine interval (1 SD)0.241 (0.039 to 0.443)0.02Interval first dose to sample (1 SD)0.027 (–0.142 to 0.197)0.750Previous COVID-191.078 (0.56 to 1.596)<0.001

Antibody Response and Maternofetal Antibody Transfer in SARS-CoV-2-Positive Pregnant Women: A Multicenter Observational Study

Introduction Awareness of SARS-CoV-2 infection in pregnant women and the potential risk for infection of their neonates is increasing. The aim of this study was to examine the immune status of affected women and evaluate the dynamics of placental antibody transfer. Materials and Methods The study included 176 women with SARS-CoV-2 infection during pregnancy who delivered between April 2020 and December 2021 at eight obstetric maternity sites. Demographic data, maternal and neonatal characteristics were summarized. Antibody testing for IgA and IgG in maternal blood sera and umbilical cord samples was evaluated and IgG transfer ratios were calculated. Values were related to the time of infection during pregnancy and birth. Results The percentage of IgG positive women increased from 29.0% (95% CI 23.8 – 37.8) at presentation with a positive PCR test result to 75.7% (95% CI 71.6 – 79.8), the percentage of IgG positive umbilical cord blood samples increased from 17.1% (95% CI 13.0 – 21.3) to 76.4% (95% CI 72.2 – 80.7) at more than six weeks after infection. Regression lines differed significantly between maternal and fetal IgG responses (p < 0.0001). Newborns react with a latency of about one week; umbilical cord blood antibody concentrations are highly correlated with maternal concentration levels (ρ = 0.8042; p < 0.0001). IgG transplacental transfer ratios were dependent on infection-to-birth interval. Two of the umbilical cord blood samples tested positive for IgA. Conclusions These findings confirm vertical SARS-CoV-2 transmission is rare; however, antibodies are transferred to the fetus soon after infection during pregnancy. Since transplacental antibody transfer might have a protective value for neonatal immunization this information may be helpful when counseling affected women.

The prevalence of hepatitis D in CHB patients in Baghdad city and its correlation with fibrosis

The aim of the study was to determine the prevalence of hepatitis D for chronic hepatitis B patients and to assess the degree of cirrhosis of hepatocytes. A study of 240 patients with CHB was studied in the laboratories of the Gastrointestinal Hospital, Dubai and Sama Dubai Specialized Medical Laboratories / Baghdad. Confirmatory examinations were conducted for them by conducting HBsAg test to ensure that they are infected with the viruses, HCV and HIV to ensure that there is no viral interference, and HDV IgG test was conducted by ELISA device to identify the male infected was (5) (31.2%) and the females was (11) (68.7%.( The results of fibrosis of the patients with hepatitis D viral showed different stages according to the severity of the infection, where it showed (S1). One infection with (6.25%) and the results of fibrosis (4.0) E(KPa), while (S2) the number of patients was (5) (21.25% ) and the incision of fibrosis ranged between (7.0 - 8.1) E(KPa), the (S3) showed the number of patients (6) (37.5%) and severity of fibrosis (8.4 -10.1) E(KPa), while (S4) which is considered to have severe fibrosis.