SARS-CoV-2 and Helicobacter pylori and some hematological parameters: A case-control study

Background: The SARS-CoV-2 associated with bacterial infection represents a serious public health challenge. Recently, there is a remarkable increase in the number of researches that confirms the effect of Helicobacter pylori on pulmonary diseases. Aim(s): The goal of this research was to see how H. pylori affected the presentation of COVID-19 infections as a prospective risk factor. Material(s) and Method(s): This research was conducted in Babylon, Iraq, from January 1, 2022, to March 5, 2022. A total of 180 people were engaged in this study, with 90 patients identified with SARS-CoV-2 by polymerase chain reaction testing and 90 people serving as a control group. Antibody screening assays on blood samples were used to look for antibodies against H. pylori. The samples were processed for complete blood count and ABO blood group. Result(s): COVID-19 infection was more frequent in females than in males, especially between 31 and 45 years. When compared to healthy people, COVID-19 patients had a higher white blood cell count (P = 0.0001) and a lower lymphocyte count (P = 0.0001). H. pylori and COVID-19 have been found to have a strong relationship, especially in females. When comparing patients to healthy people, blood group A is the most common. Conclusion(s): People with H. pylori infections are considerably more sensitive to COVID-19 than people without H. pylori infections (P = 0.011). In combination with SARS-CoV-2, IgG for H. pylori might be a risk factor.Copyright © 2023 Journal of Medical Society Published by Wolters Kluwer-Medknow.

Association of Neutralizing Antispike Monoclonal Antibody Treatment With Coronavirus Disease 2019 Hospitalization and Assessment of the Monoclonal Antibody Screening Score.

Objective: To test the hypothesis that the Monoclonal Antibody Screening Score performs consistently better in identifying the need for monoclonal antibody infusion throughout each "wave" of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant predominance during the coronavirus disease 2019 (COVID-19) pandemic and that the infusion of contemporary monoclonal antibody treatments is associated with a lower risk of hospitalization. Patients and Methods: In this retrospective cohort study, we evaluated the efficacy of monoclonal antibody treatment compared with that of no monoclonal antibody treatment in symptomatic adults who tested positive for SARS-CoV-2 regardless of their risk factors for disease progression or vaccination status during different periods of SARS-CoV-2 variant predominance. The primary outcome was hospitalization within 28 days after COVID-19 diagnosis. The study was conducted on patients with a diagnosis of COVID-19 from November 19, 2020, through May 12, 2022. Results: Of the included 118,936 eligible patients, hospitalization within 28 days of COVID-19 diagnosis occurred in 2.52% (456/18,090) of patients who received monoclonal antibody treatment and 6.98% (7,037/100,846) of patients who did not. Treatment with monoclonal antibody therapies was associated with a lower risk of hospitalization when using stratified data analytics, propensity scoring, and regression and machine learning models with and without adjustments for putative confounding variables, such as advanced age and coexisting medical conditions (eg, relative risk, 0.15; 95% CI, 0.14-0.17). Conclusion: Among patients with mild to moderate COVID-19, including those who have been vaccinated, monoclonal antibody treatment was associated with a lower risk of hospital admission during each wave of the COVID-19 pandemic.

Outcomes of Pregnant Women Exposed to Sotrovimab for the Treatment of COVID-19 in the Omicron Predominant Era (PRESTO)

Background. Sotrovimab, a monoclonal antibody with efficacy against SARS-CoV-2 including certain Omicron variants, has been used in treatment of mildmoderate COVID-19. Limited data exists regarding its use in pregnant women. Methods. Electronic medical record review of pregnant COVID-19 patients treated with sotrovimab from 12/30/21-1/31/22 (Yale New Haven Health Hospital System [YNHHS]) was performed. Included were pregnant individuals >= 12 years, weighing >= 40 kg, with positive SARS-CoV-2 test (within 10 days). Those receiving care outside YNHHS or receiving other SARS-CoV-2 treatment were excluded. We assessed demographics, medical history, and Monoclonal Antibody Screening Score (MASS). Clinical outcomes assessed included emergency department (ED) visit < 24 hours, hospitalization, ICU admission, and/or death within 29 days of sotrovimab. Pregnancy and neonatal outcomes were assessed until 8/15/22. Results. Among 22 subjects, median age was 32 years and body mass index was 27 kg/m2. Sixty-three percent were Caucasian, 9% Hispanic, 14% African-American, and 9% Asian. Nine percent had diabetes and sickle cell disease. Five percent had wellcontrolled HIV. Eighteen percent, 46%, and 36% received sotrovimab in trimester 1, 2, and 3, respectively. No infusion/allergic reactions occurred. MASS values were < 4. Only 12/22 (55%) received complete primary vaccination (46% mRNA-1273;46% BNT162b2;8% JNJ-78436735);none received a booster. There were no ICU admissions nor deaths. One subject was hospitalized for post-partum pyelonephritis;another had an ED visit for post-partum vaginal bleeding. Median gestational age at birth was 38.9 weeks. Nine percent had premature labor and premature rupture of membranes, respectively. Median infant birth weight was 3220 g. One neonate required an ICU stay due to prenatally diagnosed omphalocele (before sotrovimab) in a mother with congenital defect history. There were no abortions, fetal loss, or other birth/neurodevelopmental defects. Conclusion. Pregnant COVID-19 patients receiving sotrovimab at our center tolerated it well with good clinical outcomes. Pregnancy and neonatal complications did not appear sotrovimab-related. Though a limited sample, our data helps elucidate the safety and tolerability of sotrovimab in pregnant women.

Comparison of Scoring systems in Predicting Clinical Outcomes in Patients Hospitalized with COVID 19

Background. Previous scoring systems have been proposed to predict COVID19 outcomes, however none have been universally adopted. Two scoring systems of interest are Monoclonal Antibody Screening Score (MASS) and Oral Antiviral and Monoclonal Antibody Screening Score (OMASS).MASS prioritized patientsfor outpatient monoclonal antibody treatment based on risk of hospitalization, and OMASS was a modified version of MASS used to prioritize outpatient oral antivirals. We created a modified scoring system (UCH2021) incorporating vaccination status. These scores (table 1) have not been used to predict in-hospital clinical outcomes. We investigate these systems' abilities to predict mortality and oxygen requirements in hospitalized COVID19 patients. They do not require blood tests and allow for more rapid triage. Table 1: MASS, OMASS, UCH2021 Scoring Criteria Methods. A retrospective chart review was performed on 133 patients in two tertiary care centers between March and Sept. 2020 with RT-PCR confirmed SARS CoV2. Baseline risk factors were collected and MASS, OMASS, and UCH2021 were calculated. Primary outcomes included mortality, need for intubation, and need for supplemental oxygen >6L during hospitalization. Secondary analysis assessed if any individual risk factors were associated with those outcomes. These systems were evaluated via area under the curve calculations. Two groups based on an outcome were compared using two-sample t-tests for continuous variables and Fisher's exact tests for categorical variables. Results. All three systems demonstrated some discriminative power for mortality (table 2), but not for oxygen and intubation requirements. There was statistically significant difference in age between survivors and deceased (table 3), and BMI for oxygen requirements (table 4). Other risk factors were not predictive of mortality or oxygen requirement. Table 2: MASS, OMASS, UCH2021 Scores and Mortality in Hospitalized COVID19 Patients Table 3: Age and Mortality in Hospitalized COVID19 Patients Table 4: BMI and Oxygen Requirements in Hospitalized COVID19 Patients Conclusion. The MASS, OMASS, and UCH2021 score all had predictive power in determining in-hospital mortality, with moderate accuracy, however none were predictive of oxygen requirements. Age and BMI were also good predictors of mortality and oxygen requirements respectively. This study was completed prior to vaccine distribution in the US. Further studies would be helpful to assess if UCH2021 score has greater discriminative power in samples with vaccinated patients.

'I Just Never Wanted Them to Feel Uncomfortable -Barriers to Pharmacy-Based Identification and Treatment of Hepatitis C in Victoria, British Columbia

Background: Canada is currently on target to reach the 2030 WHO goal of HCV elimination. Continued high rates of treatment initiation are required to meet this goal. Novel models such as Tayside, Scotland pharmacy-based HCV screening and treatment have proven successful to engage people who use drugs (PWUD) in HCV therapy with a simplified, task-shifted cascade of care. This study seeks to determine whether these successes can be replicated at community pharmacies in Victoria BC. Method(s): Four community pharmacies known to work with PWUD and provide opioid agonist therapy (OAT) were trained to provide consent and perform point of care HCV antibody screening and given a standardized tool kit of resources. They were supported by a study nurse to link to HCV RNA testing when antibody positive patients were identified, with initiation of HCV treatment offered to those found to be RNA positive. Qualitative interviews were conducted with five pharmacy staff to explore their experiences with HCV testing and treatment and the feasibility of pharmacists in HCV care cascade. Result(s): Pharmacy staff completed 200 HCV OraQuick tests: 64 tested positive for HCV antibodies: 26 people were HCV RNA negative, 23 previously treated and 3 self-cleared, 2 bloodwork is pending. Of the 26 RNA positive participants, 2 are pending treatment start, 24 people have started treatment, with 12 achieving SVR. While treating identified people has been successful, less than half of projected OraQuick tests have been completed. Although the onset of the Covid 19 pandemic was a fundamental barrier incorporating HCV testing at pharmacies, stigma related to HCV and illicit drug use continues to impact this process. Pharmacists described feeling hesitant about approaching participants, especially after receiving negative responses from clients about HCV testing. Some worried their relationship would change with clients as asking about HCV implied risky drug use. Conclusion(s): This innovative pharmacy-based approach found people with limited connection to primary health care to test and treat HCV but requires more training and support to be more widely feasible.

Hcv Testing Pattern Improvements after New Universal Screening Ehr Alert Implementation at a Large Healthcare System

Background: Screening for HCV is the first critical decision point for preventing morbidity and mortality from HCV cirrhosis and hepatocellular carcinoma, and will ultimately contribute to global elimination of a curable disease. This study aims to portray the changes over time in HCV screening rates and the screened population characteristics following the 2020 implementation of an EHR alert for universal screening in the outpatient setting in a large healthcare system in the US mid-Atlantic region. Method(s): Data was ed from the EHR on all outpatients from 1/1/2017 through 10/31/2021, including individual demographics and their HCV antibody screening dates. Mixed effects multivariable regression analyses were performed to compare the timeline and characteristics of those screened and un-screened for a limited period from 1/1/2020 to 10/31/2020 and centered on the EHR alert implementation. Result(s): Absolute number of screens increased by 103% after the implementation of the EHR alert. When comparing the five-month period before and after the EHR alert, the odds of being screened at an outpatient visit increased by 62% from 17 to 27 screens per 1,000 outpatient visits. Also during this time period, patients with Medicaid were more likely to be screened than private insurance (ORadj 1.10, [CI95: 1.05, 1.15]), females more likely than males (1.26, [1.20, 1.32]);Black race more than White (1.59, [1.53, 1.64]);while those with Medicare were less likely than private insurance (0.62, [0.62, 0.65]). Over the entire 58-month period, the HCV Ab positivity rate decreased from 4.2% to 1.5%. Conclusion(s): Implementation of a universal HCV screening EHR alert was followed by a large increase in absolute screens and screening rates in the outpatient setting, despite the concurrent onset of the COVID-19 pandemic. These findings support that such an alert could play a crucial role in identification and subsequent elimination of HCV. Females, Black race and Medicaid patients were screened at higher rates, suggesting possible bias toward certain groups. Targeted testing in addition to universal screening remains a need despite much higher screening rates -expectedly, the proportion screened decreased, however the absolute number of HCV positive individuals decreased over time (data not shown). Our findings suggest that an EHR alert for universal screening could play a crucial role as the first step in identification and then elimination of HCV.

“Like what? You think I have that?”-Impact of stigma on pharmacy-based identification and treatment of hepatitis C in Victoria, British Columbia

Background and aims: Canada is currently on target to reach the 2030 WHO goal of HCV elimination. Continued high rates of treatment initiation are required to meet this goal. Novel models have proven successful to engage populations who use drugs (PWUD) in HCV therapy with a simplified, task-shifted cascade of care: Tayside, Scotland pharmacy-based HCV screening and treatment has demonstrated excellent outcomes and progress towards local HCV elimination. The EPIC Study seeks to determine whether pharmacybased treatment successes can be replicated at community pharmacies in Victoria BC. Method: Four community pharmacies known to work with PWUD and provide opioid agonist therapy (OAT) were provided training sessions to equip staff with a standardized tool kit of resources. In fall 2020, pharmacy staff were trained to provide verbal informed consent and perform point of care HCV OraQuick antibody screening. Pharmacies were supported by a study nurse to link to HCV RNA testing when antibody positive patients were identified, with initiation of HCV treatment offered to those found to be RNA positive. (Figure Presented) Figure: (: THU296): Antibody responses after the COVID-19 vaccination in patients with AILD and healthy controls. (A-B) The seropositivity rate (A) and titers (B) of anti-RBD-IgG in patients with AILD and healthy controls. (D-E) The seropositivity rate (D) and titers (E) of NAbs in patients with AILD and healthy controls. The distribution of anti-RBD-IgG (C) and NAbs (F) antibody titers over time in patients with AILD and healthy controls. AILD, autoimmune liver disease;anti-RBD-IgG, spike receptor-binding domain IgG antibody;NAbs, neutralizing antibodies. The study nurse worked with pharmacy staff to strategize adherence and support as needed by study subjects. Qualitative interviews have been conducted with five pharmacy staff to explore their experiences with testing and monitoring HCV treatment and the feasibility of involving pharmacists in the HCV care cascade. Results: To date pharmacy staff completed 171 HCV OraQuick tests finding 53 tested positive for HCV antibodies: 23 people were HCV RNA negative, (20 previously treated and 2 self-cleared), 8 unk/LTF. Of the 22 RNA positive participants, 1 is pending treatment start, 21 people have started treatment, with 8 achieving SVR. While great success has been achieved in treating identified people, less than half of projected OraQuick tests have been completed. Although the onset of the Covid 19 pandemic was a fundamental barrier incorporating HCV testing at pharmacies, stigma related to HCV and illicit drug use continues to impact this process. Pharmacists described feeling hesitant about approaching participants, especially after receiving negative responses from clients about HCV testing. Some worried their relationship would change with clients as asking about HCV implied risky drug use. Conclusion: This innovative and novel approach to HCV therapy in PWUD attempted to use a pharmacy-based approach to find people with limited connection to primary health care to test and treat HCV. Increased training of pharmacy staff related to stigma around drug use and HCV is required both before and ongoing for successful integration of pharmacy-led HCV testing and treatment in Canada.

Case report: Anti-p1 and AB blood group-A faux Para- Bombay

Background: Anti-P1 is a common antibody found in the sera of P2 donors, affecting one-quarter to two-thirds of those tested. Anti-P1 is an IgM isotype antibody that is frequently found as a weak cold agglutinin. Anti-P1 antibodies that are reactive at 37 Celsius or cause in vitro hemolysis are rare. With the exception of the rare Bombay phenotype, all red cells express the H antigen. The amount of H antigen on red cells is determined by an individual's ABO type since H antigen is the precursor to both A and B antigens. The expression of the H antigen is highest in group O and lowest in group A1B (O>A2 > B > A2B > A1 > A1B). We report a case of blood discrepancy mimicking Para-Bombay due to anti-P1 and weak H antigen expression in a 46-year-old Sarawak Malay blood donor during routine blood donor regrouping with an automated immunohematology analyser. She has history of COVID19 infection in September 2021 and she completed her 1st, 2nd and booster mRNA vaccine in November 2021. Her last pregnancy was 13 years ago, and she has no history of blood transfusions. Aims: To resolve blood group discrepancies detected when using an automated immunohematology analyser. To understand the possibility of interference from natural occurring cold-reacting red cell alloantibodies during indirect antiglobulin test blood grouping. To understand the possibility of false negative in forward grouping with anti-H antisera in donors with A1B blood group. Methods: Blood donor was typed for ABO and Rh by an automated immunohematology analyser with microplates. Serological methods for antibody detection and specification were done manually with column agglutination method (gel-card) and tube method. Results: Forward grouping of the donor's first sample with an automated analyser was strongly positive for Anti-A (4+), Anti-B (4+), Anti-AB (4+) and Anti-D (4+), while reverse grouping was also strongly positive for A1-cell (3+), B-cell (3+) and O-cell (4+). Manual serological methods with gel-card and tube method yielded similar results. Anti-H showed no reaction. The first sample was negative for Direct Coomb's test (DCT). The donor's second (repeat) sample using the manual serological method yielded similar results;however, reverse grouping repeated at 37 Celcius resulted in the cessation of reactions on known cells. Anti-H showed a 1+ reaction. Antibody screening was positive and proceeded to 11 panel antibody identification with Anti-P1 identified. DCT was negative in the second sample. (P1-) and Le(a-b+) are her phenotypes. Summary/Conclusions: Anti-P1 is commonly reported as cold reacting alloantibody in patients. In this case, a combination of strong reacting anti-P1 at room temperature and commonly low H antigen volume in A1B red cells lead to a false initial suggestion of Para- Bombay phenotype. Blood grouping discrepancies detected with automation should always be repeated manually.

Assessment of immunohaematological profile of COVID- 19 patients and its correlation with the clinical and laboratory parameters

Background: Covid-19 like other viruses, can change the immunohematological profile of the infected patients and timely identification of these changes can help in the management of these patients. There are various reports which have shown decline in haemoglobin in covid patients due to autoimmune red cell hemolysis. One recent study has shown that patients admitted in ICU have higher chances of DAT positivity as compared to non-covid patients. Aims: • To assess the Immunohematological profile of COVID-19 positive patients. • To find any correlation between the immunohematological profile and clinical spectrum of COVID-19 disease. Methods: It was a prospective observational study. Blood grouping, Direct antiglobulin test (DAT) and antibody screening (ABS) were performed on RT-PCR confirmed COVID-19 positive and COVID-19 negative patients admitted in Intensive care units and General wards of our institute. The immunohematological findings were also correlated with the patient clinical laboratory profiles. Results: A total of 205 patients were recruited. Out of which 102 were RT-PCR Covid-19 positive and 103 were negative. There was difference in blood group distribution with significantly less O group individuals in RT-PCR negative group. The overall DAT positivity was seen in 24.4% of the total 203 patients enrolled in the study. The DAT positivity was significantly higher (p value 0.01) in COVID-19 positive patients (32%) than COVID-19 negative patients (16.7%). However, there was no significant difference in the percentage of DAT positivity among patients admitted in ICU or general ward patients. Among COVID-19 positive patients, the mean haemoglobin was statistically significantly (p value 0.02) lower in DAT positive (Mean Hb: 8.5gm/dl) as compared to DAT negative patients (Mean Hb 9.6gm/dl). Also, DAT positive patients among COVID-19 positive patients were found to have significantly higher C-Reactive protein levels (p value: 0.05). There was no significant difference in other biochemical parameters between COVID-19 positive and COVID-19 negative individuals. DAT positivity was not associated with any drug intake or co-morbid state. Summary/Conclusions: Like other bacterial and viral infections, COVID-19 is also associated with DAT positivity indicating some autoimmune phenomenon due to exposure of the crypt antigens. The specificity of antibodies involved in DAT are mainly IgG and hence it may present as autoimmune hemolytic anaemia. And its association with increased inflammatory makers can help us in decision making by blood transfusion services and better management of COVID-19 patients requiring blood transfusion. .

A rapid bead-based assay for screening of SARS-CoV-2 neutralizing antibodies.

Quantitative determination of neutralizing antibodies against Severe Acute Respiratory Syndrome Corona Virus-2 (SARS-CoV-2) is paramount in immunodiagnostics, vaccine efficacy testing, and immune response profiling among the vaccinated population. Cost-effective, rapid, easy-to-perform assays are essential to support the vaccine development process and immunosurveillance studies. We describe a bead-based screening assay for S1-neutralization using recombinant fluorescent proteins of hACE2 and SARS-CoV2-S1, immobilized on solid beads employing nanobodies/metal-affinity tags. Nanobody-mediated capture of SARS-CoV-2-Spike (S1) on agarose beads served as the trap for soluble recombinant ACE2-GFPSpark, inhibited by neutralizing antibody. The first approach demonstrates single-color fluorescent imaging of ACE2-GFPSpark binding to His-tagged S1-Receptor Binding Domain (RBD-His) immobilized beads. The second approach is dual-color imaging of soluble ACE2-GFPSpark to S1-Orange Fluorescent Protein (S1-OFPSpark) beads. Both methods showed a good correlation with the gold standard pseudovirion assay and can be adapted to any fluorescent platforms for screening.

Combined Prospective Seroconversion and PCR Data of Selected Cohorts Indicate a High Rate of Subclinical SARS-CoV-2 Infections-an Open Observational Study in Lower Saxony, Germany.

Despite lockdown measures, intense symptom-based PCR, and antigen testing, the SARS-CoV-2 pandemic spread further. In this open observational study conducted in Lower Saxony, Germany, voluntary SARS-CoV-2 PCR tests were performed from April 2020 until June 2021, supported by serum antibody testing to prove whether PCR testing in subjects with none or few symptoms of COVID-19 is a suitable tool to manage the pandemic. In different mobile stations, 4,817 subjects from three different working fields participated in the PCR testing. Serum antibody screening using the SARS-CoV-2 ViraChip IgG (Viramed, Germany) and the Elecsys Anti-SARS-CoV-2 assay (Roche, Germany) was performed alongside virus neutralization testing. Subjects were questioned regarding comorbidities and COVID-19 symptoms. Fifty-one subjects with acute SARS-CoV-2 infection were detected of which 31 subjects did not show any symptoms possibly characteristic for COVID-19. An additional 37 subjects reported a previous SARS-CoV-2 infection (total prevalence 1.82%). Seroconversion was discovered in 58 subjects with known SARS-CoV-2 infection and in 58 subjects that never had a positive PCR test. The latter had a significantly lower Charlson Comorbidity Index, and one third of them were asymptomatic. In 50% of all seroconverted subjects, neutralizing serum antibodies (NAbs) were detectable in parallel to N/S1 (n = 16) or N/S1/S2 antigen specific antibodies (n = 40) against SARS-CoV-2. NAb titers decreased within 100 days after PCR-confirmed SARS-CoV-2 acute infection by at least 2.5-fold. A relatively high rate of subclinical SARS-CoV-2 infections may contribute to the spread of SARS-CoV-2, suggesting that in addition to other intervention strategies, systematic screening of asymptomatic persons by PCR testing may significantly enable better pandemic control. IMPORTANCE Within this open observational study, repeated PCR (n > 4,700) and antibody screening (n > 1,600) tests were offered in three different working fields. The study identified 51 subjects with acute SARS-CoV-2 infection and 37 subjects reported to have had a positive PCR test taken externally. Thirty-one of the 51 subjects did not display any symptoms prior to testing. In addition, 58 subjects without PCR-confirmed SARS-CoV-2 infection were identified by seroconversion. Subjects, that had undergone SARS-CoV-2 infection without having noticed, more often had a low grade of immunization with no NAbs, but may have relevantly contributed to the spread of the pandemic. Based on these results, we suggest that both regular PCR and rapid test screening of symptomatic and asymptomatic individuals, specifically within groups or workplaces identifiable as having close quarter contact, thus increased infection transference risk, is necessary to better assess and therefore reduce the spread of a pandemic virus.

The New Variants of Corona-Virus Mutations: An Understanding to Their Infectivity, Immunological Tolerance and Vaccine Efficacy

The new COVID-19 variants are triggering a fresh panic all around. Scientists still have not found any closely related identification of these variants in the context of their evolution. The scrupulous deletion/mutations recognized inside the spike protein of the variants are emerging with an amplified pace and are observed to be associated with the alterations in the receptor-binding region (RBD) of the spike protein. This paper highlights the reported mechanistic studies conducted on SARS-CoV-2 mutant variants;the mutant virus's ability in response to the antibody recognition to evade the immune system in humans. The role of cellular immunity in response to its interaction with SARS-CoV-2 variants and importantly the discussion on the antibody-dependent enhancement (ADE) of SARS-CoV-2 disease with therapeutic antibodies and vaccines has been highlighted. It is expected that this may likely be interesting and helpful for readers in clearing all their presumptions related to the spreading severity of the mutant virus strains and more importantly the effectiveness of current and upcoming vaccines for its possible control.

Multiplex bead binding assays using off-the-shelf components and common flow cytometers.

The ability to quantify protein-ligand interactions in an accurate and high-throughput manner is important in diverse areas of biology and medicine. Multiplex bead binding assays (MBBAs) are powerful methods that allow for simultaneous analysis of many protein-ligand interactions. Although there are a number of well-established MBBA platforms, there are few platforms suitable for research and development that offer rapid experimentation at low costs and without the need for specialized reagents or instruments dedicated for MBBA. Here, we describe a MBBA method that uses low-cost reagents and standard cytometers. The key innovation is the use of the essentially irreversible biotin-streptavidin interaction. We prepared a biotin-conjugated fluorescent dye and used it to produce streptavidin-coated magnetic beads that are labeled at distinct levels of fluorescence. We show the utility of our method in characterization of phage-displayed antibodies against multiple antigens of SARS-CoV-2, which substantially improves the throughput and dramatically reduces antigen consumption compared with conventional phage ELISA methods. This approach will make MBBAs more broadly accessible.