Heterotypic responses against nsp12/nsp13 from prior SARS-CoV-2 infection associates with lower subsequent endemic coronavirus incidence

Immune responses from prior SARS-CoV-2 infection and COVID-19 vaccination do not prevent re-infections and may not protect against future novel coronaviruses (CoVs). We examined the incidence of and immune differences against human endemic CoVs (eCoV) as a proxy for response against future emerging CoVs. Assessment was among those with known SARS-CoV-2 infection, COVID-19 vaccination but no documented SARS-CoV-2 infection, or neither exposure. Retrospective cohort analyses suggest that prior SARS-CoV-2 infection, but not COVID-19 vaccination alone, protects against subsequent symptomatic eCoV infection. CD8+ T cell responses to the non-structural eCoV proteins, nsp12 and nsp13, were significantly higher in individuals with previous SARS-CoV-2 infection as compared to the other groups. The three groups had similar cellular responses against the eCoV spike and nucleocapsid, and those with prior spike exposure had lower eCoV-directed neutralizing antibodies. Incorporation of non-structural viral antigens in a future pan-CoV vaccine may improve protection against future heterologous CoV infections.

Assessment of performance and implementation characteristics of rapid point of care SARS-CoV-2 antigen testing

Background: The COVID-19 pandemic has resulted in a need for rapid identification of infectious cases. Testing barriers have prohibited adequate screening for SARS-CoV-2, resulting in significant delays in commencement of treatment and outbreak control measures. This study aimed to generate evidence on the performance and implementation characteristics of the BD Veritor™ Plus System rapid antigen test as compared to reverse transcription polymerase chain reaction (RT-PCR) for diagnosis of SARS-CoV-2 in Kenya. Methods: This was a field test performance evaluation in adults undergoing testing for SARS-CoV-2. Recruited participants were classified as SARS-CoV-2-positive based on RT-PCR carried out on nasopharyngeal swabs. Antigen tests were performed with simultaneous RT-PCR on 272 participants, allowing estimation of sensitivity, specificity, positive and negative predictive values for the rapid antigen test. Implementation characteristics were assessed. Results: We enrolled 97 PCR negative symptomatic and 128 PCR negative asymptomatic, and 28 PCR positive symptomatic and 19 PCR positive asymptomatic participants. Compared to RT-PCR, the sensitivity of the rapid antigen test was 94% (95% confidence interval [CI] 86.6 to 100.0) while the specificity was 98% (95% CI 96 to 100). There was no association between sensitivity and symptom status, or between the cycle threshold value and sensitivity of the BD Veritor. The rapid test had a quick turnaround time, required minimal resources, and laboratory personnel conducting testing found it easier to use than RT-PCR. The relatively high sensitivity of BD Veritor may be partially attributed to shortages of RT-PCR testing materials, resulting in specimen analysis delays and potential degradation of viral genetic material. Therefore, in resource-constrained settings, rapid antigen tests may perform better than the reference RT-PCR, resulting in prompt institution of isolation and treatment measures.  Conclusion: The BD Veritor rapid antigen test’s high sensitivity should be interpreted with consideration to the challenges occasioned by RT-PCR testing in resource-constrained settings.

25. Immunogenicity and Reactogenicity of COVID-19 mRNA Vaccines in Allogeneic Stem Cell Transplant Recipients

Background

Allogeneic stem cell transplant (SCT) recipients are at an increased risk of poor outcomes from COVID-19. While the mRNA-1273 (Moderna) and BNT162b2 (Pfizer) COVID-19 mRNA vaccines are highly immunogenic in the general population, the immune response in SCT recipients is poorly understood. We characterized the immunogenicity and reactogenicity of COVID-19 mRNA vaccines in a cohort of SCT patients.

Methods

We performed a prospective cohort study of 16 allogeneic SCT patients and 23 healthy controls. Blood samples for both cohorts were collected prior to first vaccination (baseline), at the time of second vaccination, and approximately 28 days post-second vaccination. Anti-Spike (S), anti-S1, anti-receptor binding domain (RBD), and anti-Nucleocapsid (N) IgG levels were measured quantitatively from plasma using a multiplexed single molecule array (Simoa) immunoassay. Reactogenicity was captured for the SCT cohort via a self-reported post-vaccination diary for 7 days after each dose.

Results

Demographics and SCT recipients’ characteristics are shown in Table 1. In the SCT cohort, we observed a significantly lower anti-S (p< 0.0001), S1 (p< 0.0001), and RBD (p< 0.0001) IgG responses as compared to healthy controls, both at the time of dose 2 and 28 days post-vaccine series (Fig 1). Overall, 62.5% of SCT recipients were responders after vaccine series completion, as compared to 100% of healthy controls (Fig 2). While no patients had a reported history of COVID-19 diagnosis, 2 patients in the SCT cohort had elevated anti-S IgG levels and 1 showed elevated anti-N at baseline.

10/16 participants in the SCT cohort completed at least one post-vaccination diary. Local and systemic reactions were reported by 67% and 22% of participants, respectively, after dose 1, and 63% and 50% after dose 2 (Figure 3). All reported events were mild.

Table 1: Demographics

Figure 1: Plasma IgG Titers

Anti-Spike (A), anti-S1 (B), anti-RBD (C), and anti-nucleocapsid (D) IgG titers were measured at baseline, time of second dose, and approximately 28 days after second vaccination. IgG levels were measured quantitatively using multiplexed single molecule array (Simoa) immunoassays, and are reported as Normalized Average Enzymes per Bead (AEB). Allogeneic stem cell transplant recipients (mauve) showed significantly lower anti-S, S1, and RBD IgG responses as compared to healthy controls (mint). Low titers of anti-N IgG demonstrates no history of COVID-19 natural infection during the course of the study.

Figure 3. Solicited Local and Systemic Adverse Events

10 allogeneic stem cell transplant recipients completed at least one diary for 7 days after vaccination. Reactions after dose 1 are shown in light blue, and reactions after dose 2 are shown in dark blue. Local reactions (A) were reported by 67% (6/9) of participants after dose 1, and 63% (5/8) after dose 2. Systemic reactions (B) were reported by 22% (2/9) of participants after dose 1, and 50% (4/8) after dose 2. All reported events were mild (Grade 1).

Conclusion

Among SCT recipients, mRNA COVID-19 vaccines were well-tolerated but less immunogenic than in healthy controls. Further study is warranted to better understand heterogeneous characteristics that may affect the immune response in order to optimize COVID-19 vaccination strategies for SCT recipients.

Figure 2: Response Rate to COVID-19 Vaccination

An internally validated threshold for responders was established using pre-pandemic sera from healthy adults. A positive antibody response was was defined as individuals with anti-Spike IgG levels above the 1.07 Normalized AEB threshold.

Disclosures

Amy Joyce, NP, Kadmon (Advisor or Review Panel member) Lewis A. Novack, MS, Lumicell Inc. (Scientific Research Study Investigator, Research Grant or Support)Precision Healing, Inc. (Scientific Research Study Investigator, Research Grant or Support) David Walt, PhD, Quanterix Corporation (Board Member, Shareholder) Robert Soiffer, MD, alexion (Consultant)gilead (Advisor or Review Panel member)jazz (Advisor or Review Panel member)juno/bms (Advisor or Review Panel member)kiadis (Board Member)precision bioscience (Consultant)Rheos (Consultant)takeda (Consultant) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

586. Immunogenicity of COVID-19 mRNA Vaccines in Patients with Lymphoid Malignancies

Background

Patients with lymphoid malignancies are at high risk of severe COVID-19 disease and were not included in the phase 3 mRNA vaccine trials. Many patients with lymphoid malignancies receive immunosuppressive therapies, including B-cell depleting agents, that may negatively impact humoral response to vaccination.

Methods

We recruited patients with lymphoid malignancies and healthy participants who planned to receive two doses of SARS-CoV-2 mRNA vaccine (BNT162b2 or mRNA-1273). Blood was drawn at baseline, prior to second dose of vaccine, and 28 days after last vaccination. Disease characteristics and therapies were extracted from patients’ electronic medical record. An ultrasensitive, single molecule array (Simoa) assay detected anti-Spike (S), anti-S1, anti-receptor binding domain (RBD), and anti-Nucleocapsid (N) IgG from plasma at each timepoint.

Results

23 healthy participants and 37 patients with lymphoid malignancies were enrolled (Table 1). Low titers of anti-N (Fig 1A) demonstrate no prior exposure or acquisition of COVID-19 before vaccination or during the study. 37.8% of the lymphoid malignancy cohort responded to the vaccine, using an internally validated AEB cutoff of 1.07. A significantly higher magnitude of anti-S (p< 0.0001), anti-S1 (p< 0.0001) and anti-RBD (p< 0.0001) are present in the healthy as compared to lymphoid malignancy cohort at the second dose and day 28 post-series (Fig 1B, Fig 1C and Fig 1D). Anti-S IgG titers were compared between the healthy cohort, treatment naïve, and treatment experienced groups (Fig 2). The treatment naïve cohort had high titers by series completion which were not significantly different from the healthy cohort (p=0.2259), although the treatment experienced group had significantly decreased titers (p< 0.0001). Of the 20 patients who had received CD20 therapy, there was no clear correlation of anti-S IgG response with time from CD20 therapy, although most patients who received CD20 therapies within 12 months from the vaccine had no response (Figure 3).

Table 1. Demographics

Figure 1. Anti-N, Anti-S, Anti-S1, Anti-RBD and Anti-N Ig G for healthy v. lymphoid malignancy cohort

The dotted line at 1.07 marks in an internally validated threshold to mark anti-S IgG response. The black bars denote median with 95% CI.

Figure 2: Anti-S IgG for healthy v. treatment naïve v. treatment experienced

The dotted line at 1.07 marks in an internally validated threshold to mark antibody response. The black bars denote median with 95% CI.

Conclusion

The vaccine-induced immune response was poor among treatment-experienced patients with lymphoid malignancies, especially among those who received CD20 therapies within 12 months.

Figure 3. Months from CD20 therapy v. anti-S IgG titers

The dotted line at 1.07 marks in an internally validated threshold to mark antibody response.

Disclosures

Jennifer Crombie, MD, AbbVie (Grant/Research Support)Bauer (Grant/Research Support)Karyopharm (Consultant)MorphoSys (Consultant) Philippe Armand, MD PhD, ADCT, Celgene, Morphosys, Daiichi, Miltenyi, Tessa, C4, Genmab, Enterome, Regeneron, Genentech, Epizyme, Astra Zeneca (Consultant, Sorry to put them all in, hope you can deconvolute for me)Affimed, Adaptive, BMS, Merck, Kite, IGM, Genentech (Research Grant or Support, Institutional research funding) David Walt, PhD, Quanterix Corporation (Board Member, Shareholder) Nicolas C. Issa, MD, AiCuris (Scientific Research Study Investigator)Astellas (Scientific Research Study Investigator)GSK (Scientific Research Study Investigator)Merck (Scientific Research Study Investigator)

Single-molecule enzymology for diagnostics: profiling alkaline phosphatase activity in clinical samples

Enzymes can be used as biomarkers for a variety of diseases. However, profiling enzyme activity in clinical samples is challenging due to the heterogeneity in enzyme activity, and the low abundance of the target enzyme in biofluids. Single-molecule methods can overcome these challenges by providing information on the distribution of enzyme activities in a sample. Here, we describe the concept of using the single-molecule enzymology (SME) method to analyze enzymatic activity in clinical samples. We present recent work focused on measuring alkaline phosphatase isotypes in serum samples using SME. Future work will involve improving and simplifying this technology, and applying it to other enzymes for diagnostics.

Systems Biology Methods Applied to Blood and Tissue for a Comprehensive Analysis of Immune Response to Hepatitis B Vaccine in Adults

Conventional vaccine design has been based on trial-and-error approaches, which have been generally successful. However, there have been some major failures in vaccine development and we still do not have highly effective licensed vaccines for tuberculosis, HIV, respiratory syncytial virus, and other major infections of global significance. Approaches at rational vaccine design have been limited by our understanding of the immune response to vaccination at the molecular level. Tools now exist to undertake in-depth analysis using systems biology approaches, but to be fully realized, studies are required in humans with intensive blood and tissue sampling. Methods that support this intensive sampling need to be developed and validated as feasible. To this end, we describe here a detailed approach that was applied in a study of 15 healthy adults, who were immunized with hepatitis B vaccine. Sampling included ~350 mL of blood, 12 microbiome samples, and lymph node fine needle aspirates obtained over a ~7-month period, enabling comprehensive analysis of the immune response at the molecular level, including single cell and tissue sample analysis. Samples were collected for analysis of immune phenotyping, whole blood and single cell gene expression, proteomics, lipidomics, epigenetics, whole blood response to key immune stimuli, cytokine responses, in vitro T cell responses, antibody repertoire analysis and the microbiome. Data integration was undertaken using different approaches-NetworkAnalyst and DIABLO. Our results demonstrate that such intensive sampling studies are feasible in healthy adults, and data integration tools exist to analyze the vast amount of data generated from a multi-omics systems biology approach. This will provide the basis for a better understanding of vaccine-induced immunity and accelerate future rational vaccine design.

Finding useful biomarkers for Parkinson's disease

The recent advent of an "ecosystem" of shared biofluid sample biorepositories and data sets will focus biomarker efforts in Parkinson's disease, boosting the therapeutic development pipeline and enabling translation with real-world impact.

Training the next generation of biomedical investigators in glycosciences

This position statement originated from a working group meeting convened on April 15, 2015, by the NHLBI and incorporates follow-up contributions by the participants as well as other thought leaders subsequently consulted, who together represent research fields relevant to all branches of the NIH. The group was deliberately composed not only of individuals with a current research emphasis in the glycosciences, but also of many experts from other fields, who evinced a strong interest in being involved in the discussions. The original goal was to discuss the value of creating centers of excellence for training the next generation of biomedical investigators in the glycosciences. A broader theme that emerged was the urgent need to bring the glycosciences back into the mainstream of biology by integrating relevant education into the curricula of medical, graduate, and postgraduate training programs, thus generating a critical sustainable workforce that can advance the much-needed translation of glycosciences into a more complete understanding of biology and the enhanced practice of medicine.

Development of AccuPSATM, a novel digital immunoassay for subfemtomolar measurement of PSA in postradical prostatectomy patients

Purpose: Develop a method for measuring prostate specific antigen (PSA) in the serum of patients who have undergone radical prostatectomy (RP). The method is based on Single Molecule Array (SiMoATM) technology in which individual molecules of analyte are trapped in femtoliter microwells and counted. Measurement of PSA in post RP patients 4-6 weeks after surgery (nadir PSA levels) has potential prognostic value.

Experimental: The assay starts as a sandwich ELISA except that 2.7 μm paramagnetic beads serve as the solid phase rather than the ELISA plate. The assay is initiated by mixing sample with beads coated with anti-PSA antibody, and the mixture is incubated for two hours. During the incubation, PSA molecules are captured with an excess of beads, such that the ratio of bound PSA per bead is much less than one. Following a wash in which beads are separated using a magnet, biotinylated detector antibody is incubated with the beads for 45 minutes. After a second wash, a conjugate of streptavidin-β-galactosidase is incubated with the beads for 30 minutes to form the final enzyme immunocomplex. Upon completion, the beads are loaded onto the ends of bundles of optical fibers etched with an array of 50,000 microwells, each with a volume of 50 femtoliters (4.5 μm wide × 3.25 μm deep). Single beads are introduced into each well via a 10-minute centrifugation at 1,300 g. Excess beads are removed, and the bundles are sealed against a solution of resorufin β-D-galactopyranoside (RDG). Wells containing an enzyme immunocomplex convert RDG to a fluorescent product, which becomes concentrated in the small volume of the wells. Concentration of the fluorescent product permits ready imaging by a CCD camera and discrimination from wells that contain no enzyme immunocomplex. Poisson statistics predict that each well will contain either one PSA molecule or no PSA molecules when the ratio of bound PSA per bead is much less than one. This results in digitized quantification. Raw signal is recorded as “% active wells”, which can be converted to “average enzymes/bead” to correct for non-Poisson behavior at higher PSA concentrations. The output is related to a standard curve and converted to a PSA concentration of the sample.

Results: In preliminary validation studies across multiple runs and reagent batches, the AccuPSA assay exhibited a limit of detection (LOD) of 0.01 pg/mL, and a limit of quantification of less than 0.05 pg/mL. Linearity was demonstrated across a calibration range from 0 to 100 pg/mL, giving a five-log assay range relative to the LOD. The assay exhibited good agreement with a commercially available PSA test. PSA levels were measured in 60 post-RP specimens selected as being below the detection limit of a commercially available chemiluminescent immunoassay. All specimens gave measurable PSA results in the SiMoA PSA assay, with results ranging down to 0.014 pg/mL (0.4 fM).

Conclusion: The results suggest that PSA can be reliably measured in post RP patients with SiMoA technology. Recent results by others suggest measurement of nadir PSA following surgery may have prognostic value for recurrence-free survival. Measurement of PSA in post RP patients with AccuPSA could affirm a good prognosis, reduce unnecessary adjuvant radiation, and enable earlier detection of recurrence for earlier, more effective treatment.