Performance evaluation of novel fluorescent-based lateral immune flow assay (LIFA) for rapid detection and quantitation of total anti-SARS-CoV-2 S-RBD binding antibodies in infected individuals

1.AbstractBackgroundThe vast majority of the commercially available LFIA is used to detect SARS-CoV-2 antibodies qualitatively. Recently, a novel fluorescence-based LIFA test was developed for quantitative measurement of the total binding antibody units (BAU/mL) against the receptor-binding domain of the SARS-CoV-2 spike protein (S-RBD).AimTo evaluate the performance of the fluorescence LIFA Finecare™ 2019-nCoV S-RBD test along with its reader (Model No.: FS-113).MethodsPlasma from 150 RT-PCR confirmed-positive individuals and 100 pre-pandemic samples were tested by FinCare™ to access sensitivity and specificity. For qualitative and quantitative validation of the FinCar™ measurements, the BAU/mL results of FinCare™ were compared with results of two reference assays: the surrogate virus-neutralizing test (sVNT, GenScript, USA), and the VIDAS®3 automated assay (BioMérieux, France).ResultsFinecare™ showed 92% sensitivity and 100% specificity compared to PCR. Cohen’s Kappa statistic denoted moderate and excellent agreement with sVNT and VIDAS®3, ranging from 0.557 (95% CI: 0.32-0.78) to 0.731 (95% CI: 0.51-0.95), respectively. A strong correlation was observed between Finecare™/sVNT (r=0.7, p<0.0001) and Finecare™/VIDAS®3 (r=0.8, p<0.0001).ConclusionFinecare™ is a reliable assay and can be used as a surrogate to assess binding and neutralizing antibody response post-infection or vaccination, particularly in none or small laboratory settings.

Evaluation of the Roche SARS-CoV-2 Rapid Antibody Test in samples from vaccinated individuals

Objective The study aimed to establish the performance of the SARS-CoV-2 Rapid Antibody Test (IgG and IgM) and the Elecsys® Anti-SARS-CoV-2 S assay in vaccinated individuals. Methods A panel of serum samples from Boca Biolistics was utilized to assess antibodies following vaccination, consisting of samples drawn prior to vaccination, after the first dose, or at least 14 days after the second dose of Moderna mRNA-1273 or Pfizer-BioNTech BNT162b2 COVID-19 vaccines. Agreement between the two methods was measured and stratified by test evaluator and assay lot. Results Agreement between the SARS-CoV-2 Rapid Antibody Test (IgG) and Elecsys Anti-SARS-CoV-2 S assay qualitative measurements at the different assessment points for both mRNA-1273 and BNT162b2 ranged between 97.06% (95% confidence interval [CI] 84.67, 99.93) to 100% (95% CI 82.35, 100). Agreement of the SARS-CoV-2 Rapid Antibody Test (IgG) with the Elecsys Anti-SARS-CoV-2 S assay was not highly influenced by either lot or evaluator. There was a medium-to-strong correlation between the semi-quantitative SARS-CoV-2 Rapid Antibody Test (IgG) result and quantitative Elecsys Anti-SARS-CoV-2 S assay in samples taken after both doses of the vaccines, with higher intensity bands being associated with higher total anti-S antibody titer (mRNA-1273, p=0.0019; BNT162b2, p<0.0001). Conclusion Semi-quantitative SARS-CoV-2 Rapid Antibody Test (IgG) and quantitative Elecsys Anti-SARS-CoV-2 S assay correlated well, suggesting that the SARS-CoV-2 Rapid Antibody Test (IgG) is helpful in understanding the immune response post-vaccination. The current data support the use of the SARS-CoV-2 Rapid Antibody Test (IgG) in the vaccinated population.

583. SARS-CoV-2 Spike Protein S1/S2 Antibodies after Vaccination with Sinopharm in Peruvian Physicians

Background Peru started its national vaccination campaign in February 2021 using Sinopharm vaccine, targeting healthcare personnel on its initial phase. Although the immunogenicity of this vaccine was tested in clinical trials, there are no studies that evaluated the humoral response post vaccination in Peru. Methods We conducted a cross sectional study, which objective was to evaluate the humoral immunogenicity triggered by the Sinopharm vaccine in Peruvian physicians. We collected demographic and epidemiologic data via an electronic. The SARS-CoV-2 spike protein S1/S2 antibodies were measured by chemiluminescense (Liaison®). A positive test was defined as &gt;15 U/ml, which has correlation of 95% with neutralizing antibodies measured by plaque reduction neutralizing test. Results 92 participants were enrolled in the study. The epidemiologic characteristics are described in table 1. The mean level of antibodies measured at least 2 weeks from the second vaccine dose was 67.5 ± 70.5 U/ml. 85.7% of the study cohort had positive S1/S2 antibodies. In the univariate analysis, an imperfect negative correlation was found between the level of antibodies and participants’ age (r= -0.24; regression F test 5.25; p = 0.0242). A weak negative correlation was observed between the antibody titer and the time elapsed from the second vaccine dose and the day of antibody measurement (r= -0.17). A higher antibody level post vaccine was found in individuals who worked in COVID units (105.5 U / mL vs 58.2 U / mL; p = 0.0125), and in participants with history of COVID (216.5 U / mL vs 81.2 U / mL; p = &lt; 0.0000). Hypertension was associated with lower antibody titers (36.9 U / mL vs. 74.6; p = 0.0464). In the multivariate analysis, working in COVID units, having previous COVID infection and shorter time from second vaccine dose and day of antibody measurement were associated with higher antibody levels post vaccine (table 2). Conclusion Our study showed that the time elapsed from the second vaccine dose and the day of antibody measurement, having previous COVID-19 infection and working in COVID -19 units may help to predict higher antibody titers post vaccine. Larger studies to evaluate the humoral response post Sinopharm vaccine and its clinical implications are still needed in Peru. Disclosures All Authors: No reported disclosures

Effects of Age, Sex, Serostatus and Underlying Comorbidities on Humoral Response Post-SARS-CoV-2 Pfizer-BioNTech Vaccination: A Systematic Review

With the advent of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic, several vaccines have been developed to mitigate its spread and prevent adverse consequences of the Coronavirus Disease 2019 (COVID-19). The mRNA technology is an unprecedented vaccine, usually given in two doses to prevent SARS-CoV-2 infections. Despite effectiveness and safety, inter-individual immune response heterogeneity has been observed in recipients of mRNA-based vaccines. As a novel disease, the specific immune response mechanism responsible for warding off COVID-19 remains unclear at this point. However, significant evidence suggests that humoral response plays a crucial role in affording immunoprotection and preventing debilitating sequelae from COVID-19. As such this paper focused on the possible effects of age, sex, serostatus, and comorbidities on humoral response (i.e., total antibodies, IgG and/or IgA) of different populations post-mRNA-based Pfizer-BioNTech vaccination. A systematic search of literature was performed through PubMed, Cochrane CENTRAL, and Google Scholar. Studies were included if they reported humoral response to COVID-19 mRNA vaccines. A total of 32 studies was identified and reviewed, and the percent difference of means of reported antibody levels were calculated for comparison. Findings revealed that older individuals, the male sex, seronegativity, and those with more comorbidities mounted less humoral immune response. Given these findings, several recommendations were proposed regarding the current vaccination practices. These include giving additional doses of vaccination for immunocompromised and elderly populations. Another recommendation is conducting clinical trials in giving a combined scheme of mRNA vaccines, protein vaccines, and vector-based vaccines.

Vaccination for the novel coronavirus disease in hematological disorders

The coronavirus disease-19 (COVID-19) caused by the SARS-CoV-2 virus, is now an ongoing pandemic. First detected in December 2019 at Wuhan, China, this disease has now spread to all parts of the world. COVID-19 may affect anyone, without regard for age, sex, or underlying disease condition. Patients with benign or malignant diseases when affected, usually have a more severe outcome than people without comorbidities. Increasing one’s immunity by vaccination against COVID-19 will help to improve the disease outcomes of COVID-19 in patients who already have some underlying disease. The live-attenuated or killed and recombinant viral protein vaccines currently available can elicit both humoral and cellular immunities. However, in immunocompromised patients (either due to the disease pathology or treatment-related immunosuppression), immune response may not be as effective as expected. Depending on the underlying disease pathogenesis, the patient may not be able to mount an adequate immune response post-vaccination. However, in view of the severe risks posed by COVID-19 disease, vaccination is of utmost importance. This review aims at understanding the importance of SARS-CoV-2 vaccination in patients with hematological disorders, and also aims to understand the side effects which arise post-SARS-CoV-2 vaccination. We have tried to ascertain the best way to vaccinate patients with hematological disorders.

GnRH-Agonist Ovulation Trigger in Patients Undergoing Controlled Ovarian Hyperstimulation for IVF with Stop GnRH-Agonist Combined with Multidose GnRH-Antagonist Protocol

<b><i>Objective:</i></b> This study aimed to characterize those patients undergoing the stop gonadotropin-releasing hormone (GnRH)-agonist combined with multidose GnRH-antagonist protocol, with suboptimal response to GnRH-agonist trigger in in vitro fertilization (IVF) cycles. <b><i>Design:</i></b> This is a cohort study. <b><i>Setting:</i></b> The study was conducted in a university hospital. <b><i>Patients:</i></b> All consecutive women admitted to our IVF unit from February 2020 through November 2020 who reached the ovum pick-up stage were reviewed. <b><i>Interventions:</i></b> Triggering final oocyte maturation by GnRH-ag alone (GnRH-ag trigger group), or combined with hCG (dual trigger group), in patients undergoing the stop GnRH-agonist combined with multidose GnRH-antagonist protocol was performed. <b><i>Main Outcome Measure:</i></b> The main outcome measure was LH level 12 h after the trigger. <b><i>Results:</i></b> Five out of the 32 patients (15.6%) demonstrated suboptimal response as reflected by LH levels &#x3c;15 IU/L 12 h after GnRH-agonist trigger. Moreover, while no differences were observed in oocyte recovery rate, maturity, or embryo quality between the different study groups (GnRH-ag trigger and dual trigger groups), those achieving a suboptimal response to the GnRH-agonist trigger (post-trigger LH &#x3c;15 mIU/mL) demonstrated significantly higher number of follicles and peak estradiol levels at the day of trigger, compared to those with optimal response (post-trigger LH &#x3e;15 mIU/mL). <b><i>Conclusions:</i></b> The stop GnRH-agonist combined with GnRH-antagonist protocol enables the substitution of hCG with GnRH-ag for final oocyte maturation. However, caution should be taken in high responders, where the dual trigger with small doses of hCG (1,000–1,500 IU) should be considered, aiming to avoid suboptimal response (post-trigger LH levels &#x3c;15 IU/L).

Early immune responses have long-term associations with clinical, virologic, and immunologic outcomes in patients with COVID-19

The great majority of SARS-CoV-2 infections are mild and uncomplicated, but some individuals with initially mild COVID-19 progressively develop more severe symptoms. Furthermore, mild to moderate infections are an important contributor to ongoing transmission. There remains a critical need to identify host immune biomarkers predictive of clinical and virologic outcomes in SARS-CoV-2-infected patients. Leveraging longitudinal samples and data from a clinical trial of Peginterferon Lambda for treatment of SARS-CoV-2 infected outpatients, we used host proteomics and transcriptomics to characterize the trajectory of the immune response in COVID-19 patients within the first 2 weeks of symptom onset. We define early immune signatures, including plasma levels of RIG-I and the CCR2 ligands (MCP1, MCP2 and MCP3), associated with control of oropharyngeal viral load, the degree of symptom severity, and immune memory (including SARS-CoV-2-specific T cell responses and spike (S) protein-binding IgG levels). We found that individuals receiving BNT162b2 (Pfizer-BioNTech) vaccine had similar early immune trajectories to those observed in this natural infection cohort, including the induction of both inflammatory cytokines (e.g. MCP1) and negative immune regulators (e.g. TWEAK). Finally, we demonstrate that machine learning models using 8-10 plasma protein markers measured early within the course of infection are able to accurately predict symptom severity, T cell memory, and the antibody response post-infection.