SARS-CoV-2-host dynamics: Increased risk of adverse outcomes of COVID-19 in obesity

Background and aimThe pandemic of COVID-19 has put forward the public health system across countries to prepare themselves for the unprecedented outbreak of the present time. Recognition of the associated risks of morbidity and mortality becomes not only imperative but also fundamental to determine the prevention strategies as well as targeting the high-risk populations for appropriate therapies.MethodsWe reviewed, collated and analysed the online database i.e. Pubmed, Google scholar, Researchgate to highlight the demographic and mechanistic link between obesity and associated risks of severity in COVID-19.ResultsWe observed a changing dynamic in the reporting from the time of initial pandemic in China to currently reported research. While, initially body mass index (BMI) did not find a mention in the data, it is now clearly emerging that obesity is one of the profound risk factors for complications of COVID-19.ConclusionOur review will help clinicians and health policy makers in considering the importance of obesity in making the prevention and therapeutic strategies of COVID-19. An extra attention and precaution for patients with obesity in COVID-19 pandemic is recommended.     

Indian Publications on SARS-CoV-2: A bibliometric study of WHO COVID-19 database

Background & aimsNowadays, the whole World is under threat of Coronavirus disease (COVID-19). The ongoing COVID-19 pandemic has resulted in many fatalities and forced scientific communities to foster their Research and Development (R&D) activities. As a result, there is an enormous growth of scholarly literature on the subject. We here in this study have assessed the Indian publications contributions on COVID-19.MethodsWHO is curating global scientific literature on coronavirus since it declared COVID-19 a global pandemic through Global Research Database on COVID-19. The present study analyzed Indian publications on SARS-CoV-2 as found in WHO COVID-19 database. The research data was restricted for the period of March 2, 2020 to May 12, 2020.ResultsThe study found that there is a considerable and constant growth of Indian publications on COVID-19 from mid-April. It is interesting to note that, the most prolific authors belong to either AIIMS or ICMR institutes. Delhi state contributed highest number of publications on COVID-19. The AIIMS, New Delhi was the most productive institution in terms of publications. The Indian Journal of Medical Research has emerged as the productive journal contributing highest number of the publications. In terms of research area, the majority of the publications were related to Epidemiology.ConclusionsThe highly cited publications were of evidenced based studies. It is observed that the studies pertaining to virology, diagnosis and treatment, clinical features etc. have received highest citations than general studies on epidemiology or pandemic.     

A retrospective analysis of 12,400 SARS-CoV-2 RNA tests in patients with COVID-19 in Wuhan

The outbreak and widely spread of coronavirus disease 2019 (COVID-19) has become a global public health concern. COVID-19 has caused an unprecedented and profound impact on the whole world, and the prevention and control of COVID-19 is a global public health challenge remains to be solved. The retrospective analysis of the large scale tests of SARS-CoV-2 RNA may indicate some important information of this pandemic. We selected 12400 SARS-CoV-2 tests detected in Wuhan in the first semester of 2020 and made a systematic analysis of them, in order to find some beneficial clue for the consistent prevention and control of COVID-19.SARS-CoV-2 RNA was detected in suspected COVID-19 patients with real-time fluorescence quantitative PCR (RT-qPCR). The patients’ features including gender, age, type of specimen, source of patients, and the dynamic changes of the clinical symptoms were recorded and statistically analyzed. Quantitative and qualitive statistical analysis were carried out after laboratory detection.The positive rate of SARS-CoV-2 was 33.02% in 12,400 suspected patients’ specimens in Wuhan at the first months of COVID-19 epidemics. SARS-CoV-2 RT-qPCR test of nasopharyngeal swabs might produce 4.79% (594/12400) presumptive results. The positive rate of SARS-CoV-2 RNA was significantly different between gender, age, type of specimen, source of patients, respectively (P < .05). The median window period from the occurrence of clinical symptom or close contact with COVID-19 patient to the first detection of positive PCR was 2 days (interquartile range, 1–4 days). The median interval time from the first SARS-CoV-2 positive to the turning negative was 14 days (interquartile range, 8–19.25 days).This study reveals the comprehensive characteristics of the SARS-CoV-2 RNA detection from multiple perspectives, and it provides important clues and may also supply useful suggestions for future work of the prevention and treatment of COVID-19.     

Clinical features and viral RNA shedding of imported and local cases with COVID-19 in Wenzhou,China

Wenzhou had the highest number of confirmed novel coronavirus 2019 (COVID-19) cases outside the Hubei province. The aim of this study was to identify the difference in clinical features and viral RNA shedding between the imported and local COVID-19 cases in Wenzhou.All patients with confirmed COVID-19 admitted to Wenzhou Sixth People''s Hospital, Wenzhou Central Hospital Medical Group, from January 17 to February 11, 2020, were enrolled in this study. Data was analyzed and compared for the imported and local cases with regard to epidemiological, demographic, clinical, radiological features, and laboratory findings. Outcomes for the enrolled participants were followed up until May 7, 2020.Of the 136 cases, 50 were imported from Wuhan. The median age was 45 years and 73 (53.7%) were men. The most common symptoms at onset were fever (104 [76.5%]) and cough (85[62.5%]). Pleural effusion was more common among imported cases compared to local cases. The white blood cell count, neutrophil count, lymphocyte count and platelet count of the imported cases were significantly lower than those of the local cases, while the prothrombin time was significantly longer than that of the local cases. Severe and critically ill patients accounted for 15.4% and 2.9%, respectively. The median duration of SARS-CoV-2 RNA shedding from symptom onset was 26 days (IQR 17–32.3 days) and there were no significant differences in duration of viral RNA shedding between the two groups.The study findings suggest that imported cases from Wuhan were more likely to be severe compared to the local cases in Wenzhou. However, there was no difference between imported and local cases on the viral shedding among the COVID patients.     

High prevalence of SARS-CoV-2 detection and prolonged viral shedding in stools: A systematic review and cohort study

ObjectivesTo: 1. Describe the frequency of viral RNA detection in stools in a cohort of patients infected with SARS-CoV-2, and 2. Perform a systematic review to assess the clearance time in stools of SARS-CoV-2.MethodsWe conducted a prospective cohort study in two centers between March and May 2020. We included SARS-CoV-2 infected patients of any age and severity. We collected seriated nasopharyngeal swabs and stool samples to detect SARS-CoV-2. After, we performed a systematic review of the prevalence and clearance of SARS-CoV-2 in stools (PROSPERO-ID: CRD42020192490). We estimated prevalence using a random-effects model. We assessed clearance time by using Kaplan–Meier curves.ResultsWe included 32 patients; mean age was 43.7 ± 17.7 years, 43.8% were female, and 40.6% reported gastrointestinal symptoms. Twenty-five percent (8/32) of patients had detectable viral RNA in stools. The median clearance time in stools of the cohort was 11[10–15] days. Systematic review included 30 studies (1392 patients) with stool samples. Six studies were performed in children and 55% were male. The pooled prevalence of viral detection in stools was 34.6% (twenty-four studies, 1393 patients; 95%CI:25.4–45.1); heterogeneity was high (I²:91.2%, Q:208.6; p ≤ 0.001). A meta-regression demonstrates an association between female-gender and lower presence in stools (p = 0.004). The median clearance time in stools was 22 days (nineteen studies, 140 patients; 95%CI:19–25). After 34 days, 19.9% (95%CI:11.3–29.7) of patients have a persistent detection in stools.ConclusionsDetection of SARS-CoV-2 in stools is a frequent finding. The clearance of SARS-CoV-2 in stools is prolonged and it takes longer than nasopharyngeal secretions.     

IFITM3 Inhibits SARS-CoV-2 Infection and Is Associated with COVID-19 Susceptibility

SARS-CoV-2 has become a global threat to public health. Infected individuals can be asymptomatic or develop mild to severe symptoms, including pneumonia, respiratory distress, and death. This wide spectrum of clinical presentations of SARS-CoV-2 infection is believed in part due to the polymorphisms of key genetic factors in the population. In this study, we report that the interferon-induced antiviral factor IFITM3 inhibits SARS-CoV-2 infection by preventing SARS-CoV-2 spike-protein-mediated virus entry and cell-to-cell fusion. Analysis of a Chinese COVID-19 patient cohort demonstrates that the rs12252 CC genotype of IFITM3 is associated with SARS-CoV-2 infection risk in the studied cohort. These data suggest that individuals carrying the rs12252 C allele in the IFITM3 gene may be vulnerable to SARS-CoV-2 infection and thus may benefit from early medical intervention.     

The impact of obesity and dyslipidemia on Remdesivir effectiveness in hospitalized patients with SARS-CoV-2-related pneumonia: An observational study

Background and aimsRemdesivir (GS-5734), an inhibitor of the viral RNA-dependent, RNA polymerase was early identified as a promising therapeutic candidate against COVID-19. Our aim was to evaluate the impact of several metabolic parameters on Remdesivir effectiveness among hospitalized COVID-19 patients.Methods and resultsWe conducted an observational study on patients with SARS-CoV-2-related pneumonia admitted between May 2020 and September 2021 to the COVID-19 Units of Internal Medicine, Pneumology and Intensive Care of Garibaldi Hospital, Catania, Italy, and treated with Remdesivir. The “Ordinal Scale For Clinical Improvement” was used to assess patients’ clinical improvement within 28 days of hospitalization. Short-term mortality rate was also evaluated.A total of 142 patients with SARS-CoV-2-related pneumonia were studied. The prevalence of obesity (20.7% vs. 41.9%, p = 0.03), the average BMI (27.1 ± 4.4 vs. 31.1 ± 6.1, p < 0.01) and the mean LDL-C levels (78 ± 19 mg/dl vs. 103 ± 18 mg/dl, p = 0.03) were significantly lower in early-improved (EI) compared to not-improved (NI) individuals. Obesity was negatively associated to clinical improvement after Remdesivir (OR 0.48, 95%CI 0.17–0.97, p = 0.04). Both obesity (OR 2.82, 95% CI 1.05–7.71, p = 0.04) and dyslipidemia (OR 2.78, 95%CI 1.17–7.16, p = 0.03) were significantly related to patients’ mortality. Dyslipidemic subjects experienced a slower clinical improvement than non-dyslipidemic ones (Long-Rank p = 0.04).ConclusionOur study showed that unfavorable metabolic conditions such as obesity and dyslipidemia could predict a worse clinical response to Remdesivir as well as the mortality in hospitalized COVID-19 patients. Further prospective and larger-scale studies are needed to confirm these preliminary findings.     

COVID-19: A year later: Practical guidance for clinical laboratories for SARS-CoV-2 serology testing

The landscape of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) diagnostic testing is rapidly evolving. While serology testing has limited diagnostic capacity for acute infection, its role in providing population-based information on positivity rates and informing evidence-based decision making for public health recommendations is increasing. With the global availability of vaccines, there is increasing pressure on clinical laboratories to provide antibody screening and result interpretation for vaccinated and non-vaccinated individuals. Here we present the most up-to-date data on SARS-CoV-2 antibody timelines, including the longevity of antibodies, and the production and detection of neutralizing antibodies. Additionally, we provide practical guidance for clinical microbiology laboratories to both verify commercial serology assays and choose appropriate testing algorithms for their local populations.     

High prevalence of post COVID-19 fatigue in patients with type 2 diabetes: A case-control study

BackgroundPost COVID-19 syndrome (PCS) has emerged as a major roadblock in the recovery of patients infected with SARS-CoV-2. Amongst many symptoms like myalgia, headache, cough, breathlessness; fatigue is is most prevalent and makes the patient severely debilitated. Research on PCS, in particular fatigue, in patients with diabetes has not been done.MethodologyIn this prospective study, we included patients with type 2 diabetes (T2D) who had COVID-19 (mild to moderate severity), and matched T2D patients who did not suffer from COVID-19. Demography, anthropometry, glycemic measures, treatment, and details of COVID-19 were recorded. Symptoms were scored using Chalder Fatigue Scale (reported as fatigue score, FS) and handgrip strength (in kg) was recorded by Jamar Hydraulic Hand Dynamometer.ResultsA total of 108 patients were included (cases, 52, controls, 56). Both groups were matched for age, duration of diabetes, BMI, TSH, serum albumin and vitamin D levels. T2D patients who had COVID-19 showed significantly more fatigue when compared with patients who did not have COVID-19 but both groups had comparable handgrip strength. Furthermore, patients with T2D with previous COVID-19 infection and who had FS > 4 have had significant higher inflammation markers during acute illness, and post COVID-19, had increased post prandial blood glucose levels, lost more weight, had reduced physical activity and showed significantly lower handgrip strength as compared to those with FS < 4.ConclusionPatients with T2D who had COVID-19 infection as compared to those without had significantly more fatigue after the acute illness, and those with higher FS had reduced handgrip strength indicating sarcopenia, even after careful matching for common contributory factors to fatigue at baseline. Rehabilitation of those with FS>4 after acute infection would require careful attention to nutrition, glycemic control and graduated physical activity protocol.     

Clinical characteristics and short-term prognosis of in-patients with diabetes and COVID-19: A retrospective study from an academic center in Belgium

Background and aimsWe describe the characteristics and short-term prognosis of in-patients with diabetes and COVID-19 admitted to a Belgian academic care center.MethodsWe retrospectively reviewed the data on admission from patients with known or newly-diagnosed diabetes and confirmed COVID-19. First, survivors were compared to non-survivors to study the predictive factors of in-hospital death in patients with diabetes. Secondly, diabetic patients with SARS-CoV-2 pneumonia were matched for age and sex with non-diabetic patients with SARS-CoV-2 pneumonia, to study the prognosis and predictive factors of in-hospital death related to diabetes.ResultsSeventy-three diabetic patients were included. Mean age was 69 (±14) years. Women accounted for 52%. Most patients had type 2 diabetes (89.0%), long-term complications of hyperglycemia (59.1%), and hypertension (80.8%). The case-fatality rate (CFR) was 15%. Non-survivors had more severe pneumonia based on imaging (p 0.029) and were less often treated with metformin (p 0.036). In patients with SARS-CoV-2 pneumonia, CFR was 15.6% in diabetic (n = 64) and 25.0% in non-diabetic patients (n = 128), the difference being non-significant (p 0.194). Predictive factors of in-hospital death were elevated white blood cells count (HR 9.4, CI 1.50–58.8, p 0.016) and severe pneumonia on imaging (HR 25.0, CI 1.34–466, p 0.031) in diabetic patients, and cognitive impairment (HR 5.80, CI 1.61–20.9, p 0.007) and cardiovascular disease (HR 5.63, CI 1.54–20.6, p 0.009) in non-diabetic patients.ConclusionIn this monocentric cohort from Belgium, diabetic in-patients with COVID-19 had mostly type 2 diabetes, prevalent hyperglycemia-related vascular complications and comorbidities including hypertension. In this cohort, the CFR was not statistically different between patients with and without diabetes.     

New-Onset and Relapsed Membranous Nephropathy post SARS-CoV-2 and COVID-19 Vaccination

Since the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak and COVID-19 vaccination, new-onset and relapsed clinical cases of membranous nephropathy (MN) have been reported. However, their clinical characteristics and pathogenesis remained unclear. In this article, we collected five cases of MN associated with SARS-CoV-2 infection and 37 related to COVID-19 vaccination. Of these five cases, four (4/5, 80%) had acute kidney injury (AKI) at disease onset. Phospholipase A2 receptor (PLA2R) in kidney tissue was negative in three (3/5, 60%) patients, and no deposition of virus particles was measured among all patients. Conventional immunosuppressive drugs could induce disease remission. The underlying pathogenesis included the subepithelial deposition of viral antigens and aberrant immune response. New-onset and relapsed MN after COVID-19 vaccination generally occurred within two weeks after the second dose of vaccine. Almost 27% of patients (10/37) suffered from AKI. In total, 11 of 14 cases showed positive for PLA2R, and 20 of 26 (76.9%) presented with an elevated serum phospholipase A2 receptor antibody (PLA2R-Ab), in which 8 cases exceeded 50 RU/mL. Conventional immunosuppressive medications combined with rituximab were found more beneficial to disease remission for relapsed patients. In contrast, new-onset patients responded to conservative treatment. Overall, most patients (24/37, 64.9%) had a favorable prognosis. Cross immunity and enhanced immune response might contribute to explaining the mechanisms of MN post COVID-19 vaccination.     

Clinical predictive risk factors prolonged the duration of SARS-CoV-2 clearance in 279 moderate COVID-19 patients: A multicenter retrospective cohort study

The results of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) nucleic acid as one of the criteria has been widely applied to assess whether the coronavirus disease 2019 (COVID-19) patients could discharge, however, the risk factors that affect the duration of the SARS-CoV-2 clearance remained to be an enigma. Our research was to identify risk factors correlated with prolonged duration of the SARS-CoV-2 clearance in moderate COVID-19 patients.We retrospectively analyzed 279 consecutive ordinary COVID-19 patients in 3 hospitals in Hubei province including Huangshi Hospital of Infectious Disease, Wuhan Thunder God Mountain Hospital, and Tongji Hospital. Eight clinical characters were contained as risk factors. We used a logistic regression model and nomogram to assess the possibility that the SARS-CoV-2 nucleic acid may turn negative in 14 days.Time from symptoms onset to diagnosis (odds ratio [OR] = 3.18; 95% confidence interval [CI] 1.56–6.46; P = .001), time from onset use of antiviral drugs to onset of symptoms (OR = 0.41; 95% CI 0.23–0.72; P = .02), and bacterial coinfection (OR = 0.07; 95% CI 0.01–0.86; P = .038) were independent risks factors for the duration of SARS-CoV-2 nucleic acid clearance. The regression model showed good accuracy and sensitivity (area under the curve  = 0.96). Nomogram was also provided to predict the negative conversion rate of SARS-CoV-2 nucleic acids within 14 days.Time from symptoms onset to diagnosi, time from onset use of antiviral drugs to onset of symptoms, and bacterial coinfection were independent risk factors for the time of SARS-CoV-2 nucleic acid turning negative in ordinary COVID-19 patients. However, the age, gender, underlying disease, fungal coinfection, and duration use of antiviral drugs were irrelevant factors.     

SARS-CoV-2 Seroconversion in an Adult Horse with Direct Contact to a COVID-19 Individual

The authors report on a possible direct exposure to SARS-CoV-2 from a COVID-19-positive individual to an adult horse. The individual, diagnosed with COVID-19 (Delta B.1.617.2), had daily contact to her two horses prior to and during the development of clinical disease. None of the two horses developed abnormal clinical signs or had detectable SARS-CoV-2 in blood, nasal secretion, or feces via RT-qPCR. However, one of the two horses showed close temporal seroconversion to SARS-CoV-2 using a protein-based ELISA and the plaque reduction neutralization test. The results suggest that horses can become silently infected with SARS-CoV-2 following close contact with humans infected with SARS-CoV-2. As a precautionary measure, humans infected with SARS-CoV-2 should avoid close contact with equids and other companion animals during the time of their illness to prevent viral transmission.     

Coronavirus Disease-19 (COVID-19) associated with severe acute pancreatitis: Case report on three family members

Background/ObjectivesAbdominal pain is one of the known symptoms associated with coronavirus disease 2019. Little is known about the development of acute pancreatitis as a complication of severe acute respiratory syndrome coronavirus 2 infection. This case report describes the presentation of acute pancreatitis in two of three family members with severe COVID-19 infection.MethodsData were collected from three family members admitted with COVID-19 to the intensive care unit in March 2020. This study was reviewed and approved by the local data and ethics committee (31-1521-253).ResultsTwo of the three family members were diagnosed with acute pancreatitis associated with SARS-CoV-2. Other causes of acute pancreatitis were excluded for both patients (including alcohol, biliary obstruction/gall stones, drugs, trauma, hypertriglyceridemia, hypercalcemia, and hypotension).ConclusionsThese cases highlight acute pancreatitis as a complication associated with COVID-19 and underlines the importance of measuring pancreas-specific plasma amylase in patients with COVID-19 and abdominal pain.     

Anti-SARS CoV-2 IgG in COVID-19 Patients with Hematological Diseases: A Single-center,Retrospective Study in Japan

Objective Coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread globally. Although the relationship between anti-SARS-CoV-2 immunoglobulin G (IgG) antibodies and COVID-19 severity has been reported, information is lacking regarding the seropositivity of patients with particular types of diseases, including hematological diseases. Methods In this single-center, retrospective study, we compared SARS-CoV-2 IgG positivity between patients with hematological diseases and those with non-hematological diseases. Results In total, 77 adult COVID-19 patients were enrolled. Of these, 30 had hematological disorders, and 47 had non-hematological disorders. The IgG antibody against the receptor-binding domain of the spike protein was detected less frequently in patients with hematological diseases (60.0%) than in those with non-hematological diseases (91.5%; p=0.029). Rituximab use was significantly associated with seronegativity (p=0.010). Conclusion Patients with hematological diseases are less likely to develop anti-SARS-CoV-2 antibodies than those with non-hematological diseases, which may explain the poor outcomes of COVID-19 patients in this high-risk group.     

Convalescent plasma therapy for patients with severe COVID-19: A case series study

Coronavirus disease 2019 (COVID-19) is a novel acute respiratory infectious disease that can lead to multiple-organ dysfunction in patients with severe disease. However, there is a lack of effective antiviral drugs for COVID-19. Herein, we investigated the efficacy and safety of convalescent plasma (CP) therapy for treating severe COVID-19 in an attempt to explore new therapeutic methods.The clinical data of 3 imported patients with severe COVID-19 who underwent treatment with CP and who were quarantined and treated in a designated COVID-19 hospital from March 2020 to April 2020 were collected and analyzed.The 3 patients, including a 57-year-old male, 65-year-old female, and 59-year-old female, were clinically classified as having severe COVID-19. The main underlying diseases included hypertension, diabetes, sequelae of cerebral infarction, and postoperative thyroid adenoma. The common symptoms included cough, fever, and shortness of breath. All patients received antiviral drugs and other supportive treatments. Additionally, CP treatment was administered. At 48 to 72 hours after the CP transfusion, all 3 of the patients exhibited an improvement and alleviation of symptoms, an elevated arterial oxygen saturation, and decreased C-reactive protein and interleukin-6 levels. The counts of the total lymphocytes and T lymphocytes (CD3+) and their subsets (CD4 + and CD8+) were also obviously increased. Repeated chest computed tomography also revealed obvious absorption of the lesions in the bilateral lungs. Only 1 patient had a mild allergic reaction during the CP infusion, but no severe adverse reactions were observed.The early treatment with CP in patients with severe COVID-19 can rapidly improve the condition of the patients, and CP therapy is generally effective and safe.     

Liver test abnormalities in asymptomatic and mild COVID-19 patients and their association with viral shedding time

BACKGROUNDAsymptomatic infections and mild symptoms are common in patients infected with the Omicron variant, and data on liver test abnormalities are rare.AIMTo evaluated the clinical characteristics of asymptomatic and mild coronavirus disease 2019 (COVID-19) patients with abnormal liver test results.METHODSThis retrospective study included 661 laboratory-confirmed asymptomatic and mild COVID-19 patients who were treated in two makeshift hospitals in Ningbo from April 5, 2022 to April 29, 2022. Clinical information and viral shedding time were collected, and univariate and multivariate logistic regression models were performed in statistical analyses.RESULTSOf the 661 patients, 83 (12.6%) had liver test abnormalities, and 6 (0.9%) had liver injuries. Abnormal liver tests revealed a reliable correlation with a history of liver disease (P < 0.001) and a potential correlation with male sex and obesity (P < 0.05). Elevated alanine aminotransferase was reliably associated with obesity (P < 0.05) and a history of liver disease (P < 0.001). Elevated aspartate transaminase (AST) was reliably correlated with a history of liver disease (P < 0.001), and potentially correlated with age over 30 years (P < 0.05). There was a reliable correlation between AST ≥ 2× the upper limit of normal and a longer viral shedding time, especially in mild cases.CONCLUSIONObesity and a history of liver disease are risk factors for liver test abnormalities. Being male and an older age are potential risk factors. Attention should be given to liver tests in asymptomatic and mild COVID-19 patients, which has crucial clinical significance for evaluating the viral shedding time.     

Characterizing Kinetics and Avidity of SARS-CoV-2 Antibody Responses in COVID-19 Greek Patients

In-depth understanding of the immune response provoked by SARS-CoV-2 infection is necessary, as there is a great risk of reinfection and a difficulty in achieving herd immunity due to a decline in both antibody concentration and avidity. Avidity testing, however, could overcome variability in the immune response associated with sex or clinical symptoms, and thus differentiate between recent and past infections. In this context, here, we analyzed SARS-CoV-2 antibody kinetics and avidity in Greek hospitalized (26%) and non-hospitalized (74%) COVID-19 patients (N = 71) in the course of up to 15 months after their infection to improve the accuracy of the serological diagnosis in dating the onset of the infection. The results showed that IgG-S1 levels decline significantly at four months (p = 0.0239) in both groups of patients and are higher in hospitalized ones (up to 2.1-fold, p < 0.001). Additionally, hospitalized patients’ titers drop greatly and are equalized to non-hospitalized ones only at a time-point of twelve to fifteen months. Antibody levels of women in total remain more stable months after infection, compared to men. Furthermore, we examined the differential maturation of IgG avidity after SARS-CoV-2 infection, showing an incomplete maturation of avidity that results in a plateau at four months after infection. We also defined 38.2% avidity (sensitivity: 58.9%, specificity: 90.91%) as an appropriate “cut-off” that could be used to determine the stage of infection before avidity reaches a plateau.