SeroNet Pooling Project of immunocompromised populations

Introduction: COVID-19 vaccination substantially reduces morbidity and mortality associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe illness. However, despite effective COVID-19 vaccines many questions remain about the efficacy of vaccines and the durability and robustness of immune responses, especially in immunocompromised persons. The NCI-funded Serological Sciences Network (SeroNet) is a coordinated effort including 11 sites to advance research on the immune response to SARS-CoV-2 infection and COVID-19 vaccination among diverse and vulnerable populations. The goals of the Pooling Project are: (1) to conduct real-world data (RWD) analyses using electronic medical records (EMR) data from four health care systems (Kaiser Permanente Northern California, Northwell Health, Veterans Affairs-Case Western, and Cedars-Sinai) to determine vaccine effectiveness in (a) cancer patients;(b) autoimmune diseases and (c) solid organ transplant recipients (SOTR);(2) to conduct meta-analyses of prospective cohort studies from eight SeroNet institutions (Cedars-Sinai, Johns Hopkins, Northwell Health, Emory University, University of Minnesota, Mount Sinai, Yale University) to determine post-vaccine immune responses in (a) lung cancer patients;(b) hematologic cancers/hematopoietic stem cell transplant (HSCT) recipients;(c) SOTR;(d) lupus. Method(s): For our RWD analyses, data is extracted from EMR using standardized algorithms using ICD-10 codes to identify immunocompromised persons (hematologic and solid organ malignancy;SOTR;autoimmune disease, including inflammatory bowel disease, rheumatoid arthritis, and SLE). We use common case definitions to extract data on demographic, laboratory values, clinical co morbidity, COVID-19 vaccination, SARS-CoV-2 infection and severe COVID-19, and diseasespecific variables. In addition, we pool individual-level data from prospective cohorts enrolling patients with cancer and other immunosuppressed conditions from across network. Surveys and biospecimens from serology and immune profiling are collected at pre-specified timepoints across longitudinal cohorts. Result(s): Currently, we have EMR data extracted from 4 health systems including >715,000 cancer patients, >9,500 SOTR and >180,000 with autoimmune conditions. Prospective cohorts across the network have longitudinal data on >450 patients with lung cancer, >1,200 patients with hematologic malignancies, >400 SOTR and >400 patients with lupus. We will report results examining vaccine effectiveness for prevention of SARS-CoV-2 infection, severe COVID-19 and post-acute sequelae of COVID-19 (PAS-C or long COVID) in cancer patients compared to other immunocompromised conditions. Conclusion(s): Our goal is to inform public health guidelines on COVID-19 vaccine and boosters to reduce SARS-CoV-2 infection and severe illness in immunocompromised populations.

Hospital Protection Correlates in Outpatient Covid-19 Convalescent Plasma Recipients

Background: High titer COVID-19 convalescent plasma (CCP) reduces hospitalizations among immunocompetent outpatients. This study evaluated recipient post-transfusion S receptor binding domain (S-RBD) IgG antibody levels and the association of progressing to hospitalization among unvaccinated outpatients with COVID-19 treated with CCP or control plasma. Method(s): This analysis focused on participants from a multicenter doubleblind, randomized, controlled trial comparing treatment of outpatients with COVID-19 convalescent plasma (CCP) or control plasma without SARS-CoV-2 antibodies. Participants with confirmed SARS-CoV-2 infection were transfused within 9-days of symptom onset between June 2020 and October 2021 (n=110 vaccinated control;n=105 vaccinated CCP;n=464 unvaccinated control;n=472 unvaccinated CCP;total n=574 control and n=577 CCP recipients). All subjects had specimens collected the day prior to transfusion (D-1), within 30 minutes after transfusion (D0), 14 (D14), 28 (D28), and 90 (D90) days post-transfusion. Ancestral SARS-CoV-2 S-RBD was measured by an in-house validated ELISA. All 54 COVID-19-related hospitalizations occurred within 2 weeks of transfusion. Result(s): Post-transfusion anti-S-RBD IgG levels on D0 were significantly greater for CCP (median=4 titer,log3) compared to control (median=2 titer,log3;p< 0.001) recipients. Neither sex nor age impacted antibody levels following CCP treatment at D14, D28, and D90. Vaccinated recipients had greater titers than unvaccinated recipients prior to transfusion with little change in titers post-transfusion. Unvaccinated recipients had low antibody titers on D-1 with CCP recipients exhibiting a significant increase in titer from D-1 to D0 compared to controls (mean fold change=1.89;p< 0.001). Among unvaccinated recipients, those who received CCP transfusion late ( >5 days after symptom onset) and had low D0 antibody levels (< 4.24 titer, log3) had the greatest proportion of hospitalizations (5.5%). In contrast, those who received CCP transfusion early (< 5 days after symptom onset) with high D0 antibody levels ( >4.24 titer, log3) had no hospitalizations. Unvaccinated CCP recipient anti-S-RBD IgG antibody levels on D0 correlated with donor anti-S-RBD IgG antibody levels (r=0.30, p< 0.001). Conclusion(s): Among unvaccinated outpatients with COVID-19, CCP recipient antibody dilutional titers after transfusion over 540 titer correlated with protection against hospitalization when transfusion occurred within 5 days of symptom onset. (Figure Presented).

Antigenic Characterization of Human Monoclonal Antibodies for Therapeutic Use against H7N9 Avian Influenza Virus.

Since 2013, H7N9 avian influenza viruses (AIVs) have caused more than 1,500 human infections and the culling of millions of poultry. Despite large-scale poultry vaccination, H7N9 AIVs continue to circulate among poultry in China and pose a threat to human health. Previously, we isolated and generated four monoclonal antibodies (mAbs) derived from humans naturally infected with H7N9 AIV. Here, we investigated the hemagglutinin (HA) epitopes of H7N9 AIV targeted by these mAbs (L3A-44, K9B-122, L4A-14, and L4B-18) using immune escape studies. Our results revealed four key antigenic epitopes at HA amino acid positions 125, 133, 149, and 217. The mutant H7N9 viruses representing escape mutations containing an alanine-to-threonine substitution at residue 125 (A125T), a glycine-to-glutamic acid substitution at residue 133 (G133E), an asparagine-to-aspartic acid substitution at residue 149 (N149D), or a leucine-to-glutamine substitution at residue 217 (L217Q) showed reduced or completely abolished cross-reactivity with the mAbs, as measured by a hemagglutination inhibition (HI) assay. We further assessed the potential risk of these mutants to humans should they emerge following mAb treatment by measuring the impact of these HA mutations on virus fitness and evasion of host adaptive immunity. Here, we showed that the L4A-14 mAb had broad neutralizing capabilities, and its escape mutant N149D had reduced viral stability and human receptor binding and could be neutralized by both postinfection and antigen-induced sera. Therefore, the L4A-14 mAb could be a therapeutic candidate for H7N9 AIV infection in humans and warrants further investigation for therapeutic applications. IMPORTANCE Avian influenza virus (AIV) H7N9 continues to circulate and evolve in birds, posing a credible threat to humans. Antiviral drugs have proven useful for the treatment of severe influenza infections in humans; however, concerns have been raised as antiviral-resistant mutants have emerged. Monoclonal antibodies (mAbs) have been studied for both prophylactic and therapeutic applications in infectious disease control and have demonstrated great potential. For example, mAb treatment has significantly reduced the risk of people developing severe disease with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In addition to the protection efficiency, we should also consider the potential risk of the escape mutants generated by mAb treatment to public health by assessing their viral fitness and potential to compromise host adaptive immunity. Considering these parameters, we assessed four human mAbs derived from humans naturally infected with H7N9 AIV and showed that the mAb L4A-14 displayed potential as a therapeutic candidate.

Redesigning Biomedical Science Practicum towards a New Frontier

Due to the COVID-19 pandemic, majority of the Biomedical Science students were not able to undergo their clinical internship at diagnostic laboratories and this has created an impact on students’ skills and the future of the Malaysian healthcare system. Hence, our objective was to implement arevolutionized Biomedical Science practicum completely in a virtual environment, without compromising the learning outcomes during the pandemic in 2021. To achieve the intended learning outcomes, various online teaching-learning and assessment activities were carefully curated in accordance to standard program guidelines, learning outcomes, student learning time and thorough analysis of actual student logbooks. Learning materials were reinforced with various initiatives such as actual engagements with real-life scenarios via synchronous meetings with external panelists from hospitals. Online video-log (Vlog) and a logbook of daily activities were used as part of the assessment to ensure that students were able to learn and reflect on the activities performed. The study showed that all students displayed increased confidence levels in medical laboratory skills. They were also able to apply them in real-life situations due to the clear instructions and realistic experience via the virtual learning activities. Therefore, students who participated in the virtual practicum demonstrated almost similar levels of performance when compared to the students who went for physical practicums in the year 2020. Our virtual practicum has achieved its intended outcomes of empowering students with similar skills as those who underwent physical clinical placements in diagnostic laboratories. Those skills include successful acquisition of discipline-specific knowledge, collaborative and communication skills, as well as solid experimental methods and good laboratory practices. © 2022 by the authors.