RESUMO
Introduction: The 2019 novel coronavirus disease (COVID-19) pandemic has had devastating consequences in the US, yet clinical research on its natural history and transmission outside hospitalized settings has faced tangible and intangible challenges due to uncertainty in testing, case ascertainment, and appropriate safety measures. To better understand temporal evolution of COVID-19 related serological and other immune responses during a pandemic, we designed and implemented a baseline cross-sectional study of asymptomatic community volunteers and first responders in metro-Atlanta before the predicted infection peak in 2020. Methods: We recruited healthy community volunteers and first responders for health history, serology, and biobanking. Through an iterative process, we identified one location on our campus and one community location which were accessible, vacant, distant from COVID-19 testing sites, open for social distancing, private for informed consent, and operational for sanitation and ventilation. Research and cleaning supplies were obtained from other researchers and private online vendors due to shortages, and faculty directly participated in consenting and phlebotomy. Results: A total of 369 participants completed the study visits over six full and three half days. Over half of Phase 1 (174/299, 58.2%) and Phase 2 (45/70, 64.3%) self-reported as healthcare workers, and there was a high percentage of participants reporting exposure to known COVID-19 cases (48.2% and 61.4%). Conclusions: Rigorous prospective clinical research with informed consents and is possible during a pandemic. Effective recruitment for moderately large sample size is facilitated by direct faculty involvement, connections with the community, and non-financial support from colleagues and the institution.
RESUMO
BackgroundAccurate serological assays can improve the early diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, but few studies have compared performance characteristics between assays in symptomatic and recovered patients. MethodsWe recruited 32 patients who had 2019 coronavirus disease (COVID-19; 18 hospitalized and actively symptomatic, 14 recovered mild cases), and measured levels of IgM (against the full-length S1 or the highly homologous SARS-CoV E protein) and IgG (against S1 receptor binding domain [RBD]). We performed the same analysis in 103 pre-2020 healthy adult control (HC) participants and 13 participants who had negative molecular testing for SARS-CoV-2. ResultsAnti-S1-RBD IgG levels were very elevated within days of symptom onset for hospitalized patients (median 2.04 optical density [OD], vs. 0.12 in HC). People who recovered from milder COVID-19 only reached similar IgG levels 28 days after symptom onset. IgM levels were elevated early in both groups (median 1.91 and 2.12 vs. 1.14 OD in HC for anti-S1 IgM, 2.23 and 2.26 vs 1.52 in HC for anti-E IgM), with downward trends in hospitalized cases having longer disease duration. The combination of the two IgM levels showed similar sensitivity for COVID-19 as IgG but greater specificity, and identified 4/10 people (vs. 3/10 by IgG) with prior symptoms and negative molecular testing to have had COVID-19. ConclusionsDisease severity and timing both influence levels of IgM and IgG against SARS-CoV-2, with IgG better for early detection of severe cases but IgM more suited for early detection of milder cases.
