Project description:Safe and effective vaccines and therapeutics based on the understanding of antiviral immunity are urgently needed to end the COVID-19 pandemic. However, the understanding of these immune responses, especially cellular immune responses to SARS-CoV-2 infection, is limited. Here, we conducted a cohort study of COVID-19 patients who were followed and had blood collected to characterize the longitudinal dynamics of their cellular immune responses. Compared with healthy controls, the percentage of activation of SARS-CoV-2 S/N-specific T cells in recovered patients was significantly higher. And the activation percentage of S/N-specific CD8+ T cells in recovered patients was significantly higher than that of CD4+ T cells. Notably, SARS-CoV-2 specific T-cell responses were strongly biased toward the expression of Th1 cytokines, included the cytokines IFNγ, TNFα and IL2. Moreover, the secreted IFNγ and IL2 level in severe patients was higher than that in mild patients. Additionally, the number of IFNγ-secreting S-specific T cells in recovered patients were higher than that of N-specific T cells. Overall, the SARS-CoV-2 S/N-specific T-cell responses in recovered patients were strong, and virus-specific immunity was present until 14-16 weeks after symptom onset. Our work provides a basis for understanding the immune responses and pathogenesis of COVID-19. It also has implications for vaccine development and optimization and speeding up the licensing of the next generation of COVID-19 vaccines.
Project description:PurposeNeutralizing antibodies (NAbs) have been considered effective in preventing and treating viral infections. However, until now, the duration and clinical implications of antibody-mediated nature immunity in Koreans have remained unknown. Therefore, we examined NAbs levels and clinical characteristics in recovered coronavirus disease 2019 (COVID-19) patients.Materials and methodsBlood samples were collected from 143 adult patients who had been diagnosed with and had recovered from COVID-19 from February to March in 2020 at a tertiary-care university-affiliated hospital in Daegu, Korea. A plaque reduction neutralization test was conducted to analyze NAb titers. Individualized questionnaires were used to identify patient clinical information.ResultsThe median number of days from symptom onset to the blood collection date was 109.0 (104.0; 115.0). The NAb titers ranged from 10 to 2560. The median NAb titer value was 40. Of the 143 patients, 68 (47.6%) patients had NAb titers ≥80, and 31 (21.7%) patients had NAb titers ≥160. The higher the age or disease severity, the higher the NAb titer. In univariate logistic regression, statistically significant predictors of high NAb titers (≥80) were age, myalgia, nausea or vomiting, dyspnea, and disease severity (p<0.05). Multivariable logistic regression showed that age ≥50 years (p=0.013) and moderate or higher disease severity (p<0.001) were factors associated with high NAb titers (≥80). None of the patients had reinfection of COVID-19.ConclusionAll recovered patients were found to have NAbs regardless of the NAb titers maintained by natural immunity. Age and disease severity during COVID-19 infection were associated with high NAb titers.
Project description:ObjectivesMyocardial injury during active coronavirus disease-2019 (COVID-19) infection is well described; however, its persistence during recovery is unclear. We assessed left ventricle (LV) global longitudinal strain (GLS) using speckle tracking echocardiography (STE) in COVID-19 recovered patients and its correlation with various parameters.MethodsA total of 134 subjects within 30-45 days post recovery from COVID-19 infection and normal LV ejection fraction were enrolled. Routine blood investigations, inflammatory markers (on admission) and comprehensive echocardiography including STE were done for all.ResultsOf the 134 subjects, 121 (90.3%) were symptomatic during COVID-19 illness and were categorized as mild: 61 (45.5%), moderate: 50 (37.3%) and severe: 10 (7.5%) COVID-19 illness. Asymptomatic COVID-19 infection was reported in 13 (9.7%) patients. Subclinical LV and right ventricle (RV) dysfunction were seen in 40 (29.9%) and 14 (10.5%) patients, respectively. Impaired LVGLS was reported in 1 (7.7%), 8 (13.1%), 22 (44%) and 9 (90%) subjects with asymptomatic, mild, moderate and severe disease, respectively. LVGLS was significantly lower in patients recovered from severe illness(mild: -21 ± 3.4%; moderate: -18.1 ± 6.9%; severe: -15.5 ± 3.1%; p < 0.0001). Subjects with reduced LVGLS had significantly higher interleukin-6 (p < 0.0001), C-reactive protein (p = 0.001), lactate dehydrogenase (p = 0.009), serum ferritin (p = 0.03), and troponin (p = 0.01) levels during index admission.ConclusionsSubclinical LV dysfunction was seen in nearly a third of recovered COVID-19 patients while 10.5% had RV dysfunction. Our study suggests a need for closer follow-up among COVID-19 recovered subjects to elucidate long-term cardiovascular outcomes.
Project description:SARS-CoV-2 has caused a global pandemic with millions infected and numerous fatalities. Virus-specific antibodies can be detected in infected patients approximately two weeks after symptom onset. In this study, we set up ELISA technology coating with purified SARS-CoV-2 S and N proteins to study the antibody response of 484 serum samples. We established a surrogate viral inhibition assay using SARS-CoV-2 S protein pseudovirus system to determine the neutralization potency of collected serum samples. Here, we report robust antibody responses to SARS-CoV-2 in 484 recovered patients varying from 154 to 193 days, with 92% of recovered patients displaying a positive virus-specific spike glycoprotein IgG (s-IgG) response, while the ratio of positive spike glycoprotein IgM (s-IgM) reached 63%. Furthermore, moderate to potent neutralization activities were also observed in 62% of patients, correlating significantly with s-IgG response. This study strongly supports the long-term presence of antibodies in recovered patients against SARS-CoV-2, although all serum samples were collected from individuals with mild or moderate symptoms.
Project description:BackgroundPublic health measures to stem the coronavirus disease 2019 (COVID-19) pandemic are challenged by social, economic, health status, and cultural disparities that facilitate disease transmission and amplify its severity. Prior pre-clinical biomedical technologic advances in nucleic acid-based vaccination enabled unprecedented speed of conceptualization, development, production, and widespread distribution of mRNA vaccines that target SARS-CoV-2's Spike (S) protein.DesignTwenty-five female and male volunteer fulltime employees at the Providence VA Medical Center participated in this study to examine longitudinal antibody responses to the Moderna mRNA-1273 vaccine. IgM-S and IgG-S were measured in serum using the Abbott IgM-S-Qualitative and IgG2-S-Quantitative chemiluminescent assays.ResultsPeak IgM responses after Vaccine Dose #1 were delayed in 6 (24%) and absent in 7 (28%) participants. IgG2-S peak responses primarily occurred 40 to 44 days after Vaccine Dose #1, which was also 11 to 14 days after Vaccine Dose #2. However, subgroups exhibited Strong (n = 6; 24%), Normal (n = 13; 52%), or Weak (n = 6; 24%) peak level responses that differed significantly from each other (P < .005 or better). The post-peak IgG2-S levels declined progressively, and within 6 months reached the mean level measured 1 month after Vaccine Dose #1. Weak responders exhibited persistently low levels of IgG2-S. Variability in vaccine responsiveness was unrelated to age or gender.ConclusionHost responses to SARS-CoV-2-Spike mRNA vaccines vary in magnitude, duration and occurrence. This study raises concern about the lack of vaccine protection in as many as 8% of otherwise normal people, and the need for open dialog about future re-boosting requirements to ensure long-lasting immunity via mRNA vaccination versus natural infection.
Project description:Pregnant women are generally more susceptible to viral infection. Although the impact of SARS-CoV-2 in pregnancy remains to be determined, evidence indicates that the risk factors for severe COVID-19 are similar in pregnancy to the general population. Here we systemically analyzed the clinical characteristics of pregnant and non-pregnant female COVID-19 patients who were hospitalized during the same period and found that pregnant patients developed marked lymphopenia and higher inflammation evident by higher C-reactive protein and IL-6. To elucidate the pathways that might contribute to immunopathology or protective immunity against COVID-19 during pregnancy, we applied single-cell mRNA sequencing to profile peripheral blood mononuclear cells from four pregnant and six non-pregnant female patients after recovery along with four pregnant and three non-pregnant healthy donors. We found normal clonal expansion of T cells in the pregnant patients, heightened activation and chemotaxis in NK, NKT, and MAIT cells, and differential interferon responses in the monocyte compartment. Our data present a unique feature in both innate and adaptive immune responses in pregnant patients recovered from COVID-19.
Project description:6 patients with severe COVID-19 were followed longitudinally during hospitalization and up to 1 year after infection, when they also received a vaccine. For each time point and patient, PBMCs were collected and split into 3 pools: 1/3 was sequenced straight; from 1/3 of the samples B cells were enriched (B cell enrichment kit from StemCell) and from 1/3 of the samples, antigen-specific cells were sorted using barcoded N, S and RBD probes. All samples were further stained using a cocktail of 181 barcoded Abs. For all samples we have sequences gene-expression, B cell receptor and Cell surface proteins.
Project description:We describe the longitudinal kinetics of the serological response in COVID-19 recovered patients over a period of 14 months. The antibody kinetics in a cohort of 192 recovered patients, including 66 patients for whom follow-up serum samples were obtained at two to four clinic visits, revealed that RBD-specific antibodies decayed over the 14 months following the onset of symptoms. The decay rate was associated with the robustness of the response in that antibody levels that were initially highly elevated after the onset of symptoms subsequently decayed more rapidly. An exploration of the differences in the longitudinal kinetics between recovered patients and naïve vaccinees who had received two doses of the BNT162b2 vaccine showed a significantly faster decay in the naïve vaccinees, indicating that serological memory following natural infection is more robust than that following to vaccination. Our data highlighting the differences between serological memory induced by natural infection vs. vaccination contributed to the decision-making process in Israel regarding the necessity for a third vaccination dose.
Project description:ObjectivesTo quantify SARS-CoV2 IgG antibody titers over time and assess the longevity of the immune response in a multi-ethnic population setting.SettingThis prospective study was conducted in a tertiary hospital in Abu Dhabi city, UAE, among COVID-19 confirmed patients. The virus-specific IgG were measured quantitatively in serum samples from the patients during three visits over a period of 6 months. Serum IgG levels ≥15 AU/ml was used to define a positive response.Participants113 patients were analyzed at first visit, with a mean (SD) age of participants of 45.9 (11.8) years 87.5% of the patients were men. 63 and 27 participants had data available for visits 2 and 3, respectively.Primary outcomeChange in SARS-CoV2 IgG antibody titers over the visits.ResultsNo mortality or re-infection were reported. 69% of the patients developed positive IgG response within the first month after the onset of symptoms. The levels of IgG showed a consistent increase during the first three months with a peak level during the third month. Increasing trend in the levels of IgG were observed in 82.5%, 55.6% and 70.4% of patients between visit 1 to visit 2, visit 2 to visit 3, and from visit 1 to visit 3, respectively. Furthermore, about 64.3% of the patients showed sustained increase in IgG response for more than 120 days.ConclusionsOur study indicates a sustained and prolonged positive immune response in COVID-19 recovered patients. The consistent rise in antibody and positive levels of IgG titers within the first 5 months suggest that immunization is possible, and the chances of reinfection minimal.