Zhan, Y.L., M.C. pulmonary function or cardiac involvement and 79% were still symptomatic. Our findings suggest long-lasting immune protection after SARS-CoV-2 infection, while also ABT-639 hydrochloride highlight the risk of immune evasive variants and long-term consequences for COVID-19 survivors. Subject terms: Infectious diseases, Adaptive immunity, Outcomes research Introduction It has been more than one year since the first reported case of the novel coronavirus disease 2019 (COVID-19), which has already cost more than 2 million lives globally.1 Fortunately, vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been developed with record-breaking speed and vaccine programs are ongoing worldwide to take the pandemic under control.2 During this expansion of research focus from treatment to prevention of COVID-19, the immune evasion mechanism and immunopathogenic nature of SARS-CoV-2 adds uncertainty to the efficacy of this global vaccination effort.3 During natural infection, SARS-CoV-2 could avoid the innate antiviral ABT-639 hydrochloride response mediated by interferons (IFNs) via an array of possible strategies,4,5 which not ABT-639 hydrochloride only leads to viral replication and spreading but also could delay or impair the adaptive immune response including T cell and antibody responses.6,7 The significant prevalence of SARS-CoV-2 RNA re-positive cases among discharged patients further raises the concern about the effectiveness and persistency of immune responses after natural infection.8,9 Recent long-term follow-up surveys report significant decrease of SARS-CoV-2 antibody titers 5 to 8 months after infection,10C12 but its correlation with reduced capacity of SARS-CoV-2 neutralization and immune memory is still debatable.13,14 Besides vaccination, equally important is the recovery and rehabilitation of COVID-19 patients. 15 Mild cases usually do not require hospitalization but may share similar long-lasting symptoms or discomforts with severe cases, which may reduce life quality after recovery from COVID-19.16,17 TLR2 Also, cardiac magnet resonance imaging (cMRI) screening revealed surprisingly high prevalence of subclinical myocardial inflammation and fibrosis in recently recovered patients.18 Due to the overloading of medical systems and the fear of in-hospital transmission, long-term follow-up studies of the structural and functional recovery of COVID-19-involved organs are still limited.19 In this prospective cohort study of recovered COVID-19 patients from Xiangyang, China, we aimed ABT-639 hydrochloride to assess long-term antibody response at 12 months after infection and comprehensively evaluate the structural and functional recovery of the lung and cardiovascular systems. We also attempted to identify potential risk factors associated with those long-term consequences. Results Between January 15 through 31 March 2020, a total of 307 patients were diagnosed with COVID-19 at Xiangyang Central Hospital, which represented 55.9% of 549 cases in the downtown and 26.1% of 1175 cases city-wide. During hospitalization, 12 patients succumbed to COVID-19-induced respiratory distress or lethal infection, which translated to a mortality rate of 3.9% in line with the citywide mortality rate of 3.4% (40/1175). All 295 survivors were invited to participate in this study and the final cohort consisted of 121 survivors including 19 recovered from severe COVID-19 (Supplementary Fig. 1). Clinical procedures were performed at Xiangyang Central Hospital between 25 December 2020 and 29 January 2021. Demographic and clinical features of participants Demographic-wise, this cohort consisted of middle-aged Chinese population with an overall comorbidity prevalence of 30.6%, including hypertension (25.6%) and diabetes (6.6%) as the most common preexisting conditions, which was typical for the local agricultural and industrial population with a preference of high-salt diets (Table ?(Table1).1). The participants of this study were among the earliest confirmed COVID-19 patients with virological confirmation dates as early as January 19, 2020. Standard of care consisted of antivirals, antibiotics, immunomodulants and supplemental oxygen was given to participants following CDC guidelines (Supplementary Table 1). Only 1 1 in this cohort received invasive ventilation (Supplementary Table 1), which reflected the dismal mortality rate among critically ill patients relying on respiratory support.20 Of note, the basic characteristics of this cohort were comparable with the entire population of COVID-19 survivors treated at this hospital (Supplementary Table 2). Table 1 Characteristics of participants by COVID-19 severity values were calculated by Fishers exact test (data with only 1 1 row) or Chi-square test (multi-row data) for categorical variables, and by MannCWhitney test for continuous variables between the two groups After stratifying the cohort by severity graded according to the guideline,21 severe groups.