Many unknowns exist about human immune responses to the SARS-CoV-2 virus. SARS-CoV-2 reactive CD4+ T cells have been reported in unexposed individuals, suggesting pre-existing cross-reactive T cell memory in 20-50% of people. However, the source of those T cells has been speculative. Using human blood samples derived before the SARS-CoV-2 virus was discovered in 2019, we mapped 142 T cell epitopes across the SARS-CoV-2 genome to facilitate precise interrogation of the SARS-CoV-2-specific CD4+ T cell repertoire. We demonstrate a range of pre-existing memory CD4+ T cells that are cross-reactive with comparable affinity to SARS-CoV-2 and the common cold coronaviruses HCoV-OC43, HCoV-229E, HCoV-NL63, or HCoV-HKU1. Thus, variegated T cell memory to coronaviruses that cause the common cold may underlie at least some of the extensive heterogeneity observed in COVID-19 disease.

Since the initial identification of the novel coronavirus SARS-CoV-2 in December of 2019, researchers have raced to understand its pathogenesis and begun devising vaccine and treatment strategies. An accurate understanding of the body’s temporal immune response against SARS-CoV-2 is paramount to successful vaccine development and disease progression monitoring. To provide insight into the antibody response against SARS-CoV-2, plasma samples from 181 PCR-confirmed COVID-19 patients collected at various timepoints post-symptom onset (PSO) were tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies via lateral flow. Additionally, 21 donors were tracked over time to elucidate patient-specific immune responses. We found sustained levels of anti-SARS-CoV-2 antibodies past 130 days PSO, with 99% positivity observed at 31–60 days PSO. By 61–90 days PSO, the percentage of IgM-/IgG+ results were nearly equal to that of IgM+/IgG+ results, demonstrating a shift in the immune response with a decrease in IgM antibody levels. Results from this study not only provide evidence that the antibody response to COVID-19 can persist for over 4 months, but also demonstrates the ability of Easy Check™ to monitor seroconversion and antibody response of patients. Easy Check was sufficiently sensitive to detect antibodies in patient samples as early as 1–4 days PSO with 86% positivity observed at 5–7 days PSO. Further studies are required to determine the longevity and efficacy of anti-SARS-CoV-2 antibodies, and whether they are protective against re-infection.

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Background Recent epidemiological data indicate that minority groups, especially Hispanic communities, experience higher rates of infection, hospitalization, and death due to COVID-19. It is important to understand the nature of this health disparity and the socioeconomic or behavioral factors that are placing Hispanic communities and other minority populations at higher risk for morbidity and mortality. Objective The purpose of this project is to assess current COVID-19–related knowledge, attitudes, and practices (KAP) among a predominantly Hispanic population from Orange County, California, and identify risk factors that may contribute to increased susceptibility and vulnerability to contracting SARS-CoV-2. Methods Our Orange County–wide community survey consists of quantitative survey questions in four domains: demographic information, COVID-19 knowledge questions, COVID-19 attitude questions, and COVID-19 practices questions. The survey questions are adapted from recent global KAP studies. Participants are being recruited from Amistad Medical Clinic, a private primary health clinic group in Orange County that treats a predominantly Hispanic population. Patients recruited during telehealth visits are surveyed remotely by telephone, and those recruited during in-person clinic visits are surveyed in person. Surveys are conducted by trained members of the study team who are native to the community setting. Results As of October 12, 2020, we had recruited and enrolled 327 participants. Data collection occurred June 26th to October 30th. Data analysis is ongoing. Conclusions Very few current COVID-19 studies focus on the perspective and experience of minority populations. Because Hispanic communities are disproportionately affected by COVID-19, it is important to understand the factors the contribute to this disparity and the next steps that should be taken to reduce the COVID-19 burden in this population. We believe that our study model of partnering with a local clinic system that serves our study population can be expanded to other settings to compare COVID-19 KAP and associated factors within different minority communities. International Registered Report Identifier (IRRID) DERR1-10.2196/25265

Background Tuberculosis (TB) is the most common co-infection among people living with HIV, but HIV positivity is associated with a lower Mycobacterium tuberculosis (MTB) bacillary load in sputum, making TB often difficult to diagnose with current diagnostic solutions. GeneXpert MTB/RIF (Cepheid, USA), a rapid, molecular diagnostic assay, has transformed the TB diagnostic landscape and can be used to diagnose TB and limited drug resistance in HIV patients from direct clinical samples in < 2 hours, but results can be significantly affected by sample bacterial load, which is quantified by the GeneXpert MTB/RIF (Xpert) instrument using Ct values. Our primary objective was to assess how a patient’s HIV status affected their MTB bacterial load in sputum vs. saliva samples submitted for Xpert diagnosis of TB. Methods We completed a retrospective analysis of >4,000 patient records from the Myanmar National TB Program captured as part of a nation-wide electronic reporting system developed with the assistance of FIND (Geneva). De-identified records included HIV status, Xpert testing results, and for a subset of patients, specimen type. With this diagnostic information, we compared the distribution of MTB load (quantified by Xpert Ct values) in sputum and saliva in HIV positive vs. HIV negative patients using STATA. Results Based on mean Ct value comparison independent of HIV status, saliva samples (mean Ct = 22.7) contained a significantly lower bacterial load of MTB as compared to sputum samples (mean Ct=19.2, p < .001).Within saliva samples, a lower bacterial load was also detected in HIV positive patients (mean Ct = 26.9) compared to HIV negative patients (mean Ct = 22.3, p< .05). Similarly, in sputum samples, a lower bacterial load was detected in HIV positive patients (mean Ct = 21.6) compared to HIV negative patients (mean Ct = 19.0, p < .001) (Figure 1). Figure 1. Ct Values by HIV Status and Specimen Type Conclusion Sputum samples have a significantly higher bacterial load on average compared to saliva samples independent of HIV status. Additionally, when looking at both saliva and sputum as sample types, HIV positive patients have significantly lower bacterial load than individuals who are HIV negative. Based on these results, sputum is the optimal sample type for Xpert TB detection, especially in people living with HIV. Disclosures All Authors: No reported disclosures