Characterization of long-term patient-reported symptoms of COVID-19: an analysis of social media data (preprint)

As the SARS-CoV-2 virus (COVID-19) continues to affect people across the globe, there is limited understanding of the long term implications for infected patients. While some of these patients have documented follow-ups on clinical records, or participate in longitudinal surveys, these datasets are usually designed by clinicians, and not granular enough to understand the natural history or patient experiences of "long COVID". In order to get a complete picture, there is a need to use patient generated data to track the long-term impact of COVID-19 on recovered patients in real time. There is a growing need to meticulously characterize these patients' experiences, from infection to months post-infection, and with highly granular patient generated data rather than clinician narratives. In this work, we present a longitudinal characterization of post-COVID-19 symptoms using social media data from Twitter. Using a combination of machine learning, natural language processing techniques, and clinician reviews, we mined 296,154 tweets to characterize the post-acute infection course of the disease, creating detailed timelines of symptoms and conditions, and analyzing their symptomatology during a period of over 150 days.

SARS-CoV-2 infection and COVID-19 severity in individuals with prior seasonal coronavirus infection. (preprint)

A sizable fraction of healthy blood donors have cross-reactive T cells to SARS-CoV-2 peptides due to prior infection with seasonal coronavirus. Understanding the role of cross-reactive T cells in immunity to SARS-CoV-2 has implications for managing the COVID-19 pandemic. We show that individuals with documented history of seasonal coronavirus have a similar SARS-CoV-2 infection rate and COVID-19 severity as those with no prior history of seasonal coronavirus. Our findings suggest prior infection with seasonal coronavirus does not provide immunity to subsequent infection with SARS-CoV-2.

SARS-CoV-2 Antibody Responses Correlate with Resolution of RNAemia But Are Short-Lived in Patients with Mild Illness (preprint)

SARS-CoV-2-specific antibodies, particularly those preventing viral spike receptor binding domain (RBD) interaction with host angiotensin-converting enzyme 2 (ACE2) receptor, could offer protective immunity, and may affect clinical outcomes of COVID-19 patients. We analyzed 625 serial plasma samples from 40 hospitalized COVID-19 patients and 170 SARS-CoV-2-infected outpatients and asymptomatic individuals. Severely ill patients developed significantly higher SARS-CoV-2-specific antibody responses than outpatients and asymptomatic individuals. The development of plasma antibodies was correlated with decreases in viral RNAemia, consistent with potential humoral immune clearance of virus. Using a novel competition ELISA, we detected antibodies blocking RBD-ACE2 interactions in 68% of inpatients and 40% of outpatients tested. Cross-reactive antibodies recognizing SARS-CoV RBD were found almost exclusively in hospitalized patients. Outpatient and asymptomatic individuals' serological responses to SARS-CoV-2 decreased within 2 months, suggesting that humoral protection may be short-lived.

A lesson from COVID-19 on inaccessibility of web-based information for disabled populations worldwide (preprint)

Many government websites and mobile content are inaccessible for people with vision, hearing, and cognitive disabilities. The COVID-19 pandemic highlighted these disparities when health authority website information, critical in providing resources for curbing the spread of the virus, remained inaccessible for disabled populations. The Web Content Accessibility Guidelines provide comparatively universally accepted guidelines for website accessibility. We utilized these parameters to examine the number of countries with or without accessible health authority websites. The resulting data indicate a dearth of countries with websites accessible for persons with disabilities. Methods of information dissemination must take into consideration individuals with disabilities, particularly in times of global health crises.

SARS-Cov-2-, HIV-1-, Ebola-neutralizing and anti-PD1 clones are predisposed (preprint)

Antibody repertoire refers to the totality of the superbly diversified antibodies within an individual to cope with the vast array of possible pathogens. Despite this extreme diversity, antibodies of the same clonotype, namely public clones, have been discovered among individuals. Although some public clones could be explained by antibody convergence, public clones in naive repertoire or virus-neutralizing clones from not infected people were also discovered. All these findings indicated that public clones might not occur by random and they might exert essential functions. However, the frequencies and functions of public clones in a population have never been studied. Here, we integrated 2,449 Rep-seq datasets from 767 donors and discovered 5.07 million public clones - ~10% of the repertoire are public in population. We found 38 therapeutic clones out of 3,390 annotated public clones including anti-PD1 clones in healthy people. Moreover, we also revealed clones neutralizing SARS-CoV-2, Ebola, and HIV-1 viruses in healthy individuals. Our result demonstrated that these clones are predisposed in the human antibody repertoire and may exert critical functions during particular immunological stimuli and consequently benefit the donors. We also implemented RAPID - a Rep-seq Analysis Platform with Integrated Databases, which may serve as a useful tool for others in the field.

Occurrence and Timing of Subsequent SARS-CoV-2 RT-PCR Positivity Among Initially Negative Patients (preprint)

Background: SARS-CoV-2 reverse transcriptase polymerase chain reaction (RT-PCR) testing remains the cornerstone of laboratory-based identification of patients with COVID-19. As the availability and speed of SARS-CoV-2 testing platforms improve, results are increasingly relied upon to inform critical decisions related to therapy, use of personal protective equipment, and workforce readiness. However, early reports of RT-PCR test performance have left clinicians and the public with concerns regarding the reliability of this predominant testing modality and the interpretation of negative results. In this work, two independent research teams report the frequency of discordant SARS-CoV-2 test results among initially negative, repeatedly tested patients in regions of the United States with early community transmission and access to testing. Methods: All patients at the University of Washington (UW) and Stanford Health Care undergoing initial testing by nasopharyngeal (NP) swab between March 2nd and April 7th, 2020 were included. SARS-CoV-2 RT-PCR was performed targeting the N, RdRp, S, and E genes and ORF1ab, using a combination of Emergency Use Authorization laboratory-developed tests and commercial assays. Results through April 14th were extracted to allow for a complete 7-day observation period and an additional day for reporting. Results: A total of 23,126 SARS-CoV-2 RT-PCR tests (10,583 UW, 12,543 Stanford) were performed in 20,912 eligible patients (8,977 UW, 11,935 Stanford) undergoing initial testing by NP swab; 626 initially test-negative patients were re-tested within 7 days. Among this group, repeat testing within 7 days yielded a positive result in 3.5% (4.3% UW, 2.8% Stanford) of cases, suggesting an initial false negative RT-PCR result; the majority (96.5%) of patients with an initial negative result who warranted reevaluation for any reason remained negative on all subsequent tests performed within this window. Conclusions: Two independent research teams report the similar finding that, among initially negative patients subjected to repeat SARS-CoV-2 RT-PCR testing, the occurrence of a newly positive result within 7 days is uncommon. These observations suggest that false negative results at the time of initial presentation do occur, but potentially at a lower frequency than is currently believed. Although it is not possible to infer the clinical sensitivity of NP SARS-CoV-2 RT-PCR testing using these data, they may be used in combination with other reports to guide the use and interpretation of this common testing modality.

High frequency of SARS-CoV-2 RNAemia and association with severe disease (preprint)

BackgroundDetection of SARS-CoV-2 RNA in the blood, also known as RNAemia, has been reported, but its prognostic implications are not well understood. This study aimed to determine the frequency of SARS-CoV-2 RNA in plasma and its association with the clinical severity of COVID-19. MethodsAn analytical cross-sectional study was performed in a single-center tertiary care institution in northern California and included consecutive inpatients and outpatients with COVID-19 confirmed by detection of SARS-CoV-2 RNA in nasopharyngeal swab specimens. The prevalence of SARS CoV-2 RNAemia and the strength of its association with clinical severity variables were examined and included the need for transfer to an intensive care unit (ICU), mechanical ventilation and 30-day all-cause mortality. ResultsPaired nasopharyngeal and plasma samples were included from 85 patients. The overall median age was 55 years, and individuals with RNAemia were older than those with undetectable SARS-CoV-2 RNA in plasma (63 vs 50 years; p=0.001). Comorbidities were frequent including obesity (37.7%), hypertension (30.6%) and diabetes mellitus (22.4%). RNAemia was detected in a total of 28/85 (32.9%) individual patients, including 22/28 (78.6%) who required hospital admission. RNAemia was detected more frequently in individuals who developed severe disease including the need for ICU transfer (32.1% vs 14.0%; p=0.05), mechanical ventilation (21.4% vs 3.5%; p=0.01) and 30-day all-cause mortality (14.3% vs 0%; p=0.01). No association was detected between RNAemia and estimated levels of viral RNA in the nasopharynx. An additional 121 plasma samples from 28 individuals with RNAemia were assessed longitudinally, and RNA was detected for a maximum duration of 10 days. ConclusionThis study demonstrated a high proportion of SARS-CoV-2 RNAemia, and an association between RNAemia and clinical severity suggesting the potential utility of plasma viral testing as a prognostic indicator for COVID-19.

Measure what matters: counts of hospitalized patients are a better metric for health system capacity planning for a reopening (preprint)

Responding to the COVID-19 pandemic requires accurate forecasting of health system capacity requirements using readily available inputs. We examined whether testing and hospitalization data could help quantify the anticipated burden on the health system given shelter-in-place (SIP) order. We find a marked slowdown in the hospitalization rate within ten days of SIP even as cases continued to rise. We also find a shift towards younger patients in the age distribution of those testing positive for COVID-19 over the four weeks of SIP. The impact of this shift is a divergence between increasing positive case confirmations and slowing new hospitalizations, both of which affects the demand on health systems. Without using local hospitalization rates and the age distribution of positive patients, current models are likely to overestimate the resource burden of COVID-19. It is imperative that health systems start using these data to quantify effects of SIP and aid reopening planning.