scholarly journals Coronavirus protective immunity is short-lasting

2020 ◽  
Author(s):  
Arthur W. D. Edridge ◽  
Joanna Kaczorowska ◽  
Alexis C. R. Hoste ◽  
Margreet Bakker ◽  
Michelle Klein ◽  
...  
Keyword(s):  
Post Infection ◽  
Healthy Subjects ◽  
Protective Immunity ◽  
Substantial Reduction ◽  
Time Span ◽  
Acquired Immunity ◽  
Recent Emergence ◽  
Human Coronaviruses ◽  
Antibody Levels

ABSTRACTIn the current COVID-19 pandemic a key unsolved question is the duration of acquired immunity in recovered individuals. The recent emergence of SARS-CoV-2 precludes a direct study on this virus, but the four seasonal human coronaviruses may reveal common characteristics applicable to all human coronaviruses. We monitored healthy subjects over a time span of 35 years (1985-2020), providing a total of 2473 follow up person-months, and determined a) the time to reinfection by the same seasonal coronavirus and b) the dynamics of coronavirus antibody depletion post-infection. An alarmingly short duration of protective immunity to coronaviruses was found. Reinfections occurred frequently at 12 months post-infection and there was for each virus a substantial reduction in antibody levels as soon as 6 months post-infection.

scholarly journals Assessment of avidity related to IgG subclasses in SARS-CoV-2 Brazilian infected patients

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrew D. Moura ◽  
Hernan H. M. da Costa ◽  
Victor A. Correa ◽  
Ana K. de S. Lima ◽  
José A. L. Lindoso ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Vaccine Development ◽  
Immunological Response ◽  
Hospitalized Patients ◽  
Igg Antibody ◽  
Antibody Avidity ◽  
Mild Disease ◽  
Life Threatening ◽  
Antibody Levels

AbstractSARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still limited for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefined. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RBD IgG-ELISA showed 100% of specificity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 8–14 and 15–21 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P < 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the first weeks of symptoms onset. Our findings constitute the effort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RBD in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more significant potential for life-threatening.

scholarly journals Multifactorial seroprofiling dissects the contribution of pre-existing human coronaviruses responses to SARS-CoV-2 immunity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Irene A. Abela ◽  
Chloé Pasin ◽  
Magdalena Schwarzmüller ◽  
Selina Epp ◽  
Michèle E. Sickmann ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Rapid Development ◽  
Antibody Responses ◽  
Human Coronavirus ◽  
Neutralization Activity ◽  
Accurate Definition ◽  
Human Coronaviruses ◽  
Definition Of ◽  
Antibody Levels

AbstractDetermination of SARS-CoV-2 antibody responses in the context of pre-existing immunity to circulating human coronavirus (HCoV) is critical for understanding protective immunity. Here we perform a multifactorial analysis of SARS-CoV-2 and HCoV antibody responses in pre-pandemic (N = 825) and SARS-CoV-2-infected donors (N = 389) using a custom-designed multiplex ABCORA assay. ABCORA seroprofiling, when combined with computational modeling, enables accurate definition of SARS-CoV-2 seroconversion and prediction of neutralization activity, and reveals intriguing interrelations with HCoV immunity. Specifically, higher HCoV antibody levels in SARS-CoV-2-negative donors suggest that pre-existing HCoV immunity may provide protection against SARS-CoV-2 acquisition. In those infected, higher HCoV activity is associated with elevated SARS-CoV-2 responses, indicating cross-stimulation. Most importantly, HCoV immunity may impact disease severity, as patients with high HCoV reactivity are less likely to require hospitalization. Collectively, our results suggest that HCoV immunity may promote rapid development of SARS-CoV-2-specific immunity, thereby underscoring the importance of exploring cross-protective responses for comprehensive coronavirus prevention.

scholarly journals Serological Assessment of COVID-19 Patients in Brazil: Levels, Avidity, and Subclasses of IgG Against RBD

2021 ◽  
Author(s):  
Andrew Moura ◽  
Hernan H. da Costa ◽  
Victor Correa ◽  
Ana K. Lima ◽  
José A. Lindoso ◽  
...  
Keyword(s):  
Protective Immunity ◽  
Vaccine Development ◽  
Immunological Response ◽  
Hospitalized Patients ◽  
Igg Antibody ◽  
Antibody Avidity ◽  
Mild Disease ◽  
Life Threatening ◽  
Antibody Levels

Abstract SARS-CoV-2 is considered a global emergency, resulting in an exacerbated crisis in the health public in the world. Although there are advances in vaccine development, it is still not available for many countries. On the other hand, an immunological response that mediates protective immunity or indicates that predict disease outcome in SARS-CoV-2 infection remains undefined. This work aimed to assess the antibody levels, avidity, and subclasses of IgG to RBD protein, in symptomatic patients with severe and mild forms of COVID-19 in Brazil using an adapted in-house RBD-IgG ELISA. The RDB IgG-ELISA showed 100% of specificity and 94.3% of sensibility on detecting antibodies in the sera of hospitalized patients. Patients who presented severe COVID-19 had higher anti-RBD IgG levels compared to patients with mild disease. Additionally, most patients analyzed displayed low antibody avidity, with 64.4% of the samples of patients who recovered from the disease and 84.6% of those who died in this avidity range. Our data also reveals an increase of IgG1 and IgG3 levels since the 8th day after symptoms onset, while IgG4 levels maintained less detectable during the study period. Surprisingly, patients who died during 8-14 and 15-21 days also showed higher anti-RBD IgG4 levels in comparison with the recovered (P < 0.05), suggesting that some life-threatening patients can elicit IgG4 to RBD antibody response in the first weeks of symptoms onset. Our findings constitute the effort to clarify IgG antibodies' kinetics, avidity, and subclasses against SARS-CoV-2 RDB in symptomatic patients with COVID-19 in Brazil, highlighting the importance of IgG antibody avidity in association with IgG4 detection as tool laboratory in the follow-up of hospitalized patients with more significant potential for life-threatening.

scholarly journals Schistosoma mansoni: protective immunity in mice cured by chemotherapy at the chronic phase of the disease

1993 ◽  
Vol 35 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Fernando Schemelzer de Moraes Bezerra ◽  
Paulo Marcos Zech Coelho ◽  
Carlos Alberto Pereira Tavares
Keyword(s):  
Schistosoma Mansoni ◽  
Protective Immunity ◽  
Chronic Phase ◽  
Treated Group ◽  
Acquired Immunity ◽  
Elisa Method ◽  
Antibody Levels

Aiming at demonstrating a decrease of acquired immunity after chemotherapeutic cure, a group of mice was infected with 25 Schistosoma mansoni cercariae (LE strain). A part of these animals was treated with 400 mg/kg oxamniquine, at 120 days after infection. Challenge infections were carried out at 45, 90 and 170-day-intervals after treatment (185, 210 and 290 days after primoinfection, respectively). Recovery of worms at 20 days after reinfections showed that a residual immunity remains up to 90 days after treatment, and disappears at 170 days after cure. Using the ELISA method, it was possible to detect a decrease of antibody levels (total IgG) in the treated group, when antigens from different evolutive stages of S. mansoni were used. The epidemiological implications of the present results, and the possible mechanisms involved in the decrease of acquired immunity after treatment are discussed.

scholarly journals Waning antibody responses in COVID-19: what can we learn from the analysis of other coronaviruses?

Infection ◽  
2021 ◽  
Author(s):  
Ali Hamady ◽  
JinJu Lee ◽  
Zuzanna A. Loboda
Keyword(s):  
Cross Reactivity ◽  
Antibody Responses ◽  
The Novel ◽  
Incidence And Mortality ◽  
Antibody Titres ◽  
Human Coronaviruses ◽  
Public Health Strategies ◽  
Antibody Dynamics

Abstract Objectives The coronavirus disease 2019 (COVID-19), caused by the novel betacoronavirus severe acute respiratory syndrome 2 (SARS-CoV-2), was declared a pandemic in March 2020. Due to the continuing surge in incidence and mortality globally, determining whether protective, long-term immunity develops after initial infection or vaccination has become critical. Methods/Results In this narrative review, we evaluate the latest understanding of antibody-mediated immunity to SARS-CoV-2 and to other coronaviruses (SARS-CoV, Middle East respiratory syndrome coronavirus and the four endemic human coronaviruses) in order to predict the consequences of antibody waning on long-term immunity against SARS-CoV-2. We summarise their antibody dynamics, including the potential effects of cross-reactivity and antibody waning on vaccination and other public health strategies. At present, based on our comparison with other coronaviruses we estimate that natural antibody-mediated protection for SARS-CoV-2 is likely to last for 1–2 years and therefore, if vaccine-induced antibodies follow a similar course, booster doses may be required. However, other factors such as memory B- and T-cells and new viral strains will also affect the duration of both natural and vaccine-mediated immunity. Conclusion Overall, antibody titres required for protection are yet to be established and inaccuracies of serological methods may be affecting this. We expect that with standardisation of serological testing and studies with longer follow-up, the implications of antibody waning will become clearer.

scholarly journals Circulating CD4 T cells elicited by endemic coronaviruses display vast disparities in abundance and functional potential linked to both antigen specificity and age

2021 ◽  
Author(s):  
Katherine A Richards ◽  
Maryah Glover ◽  
Jeremy C Crawford ◽  
Paul Thomas ◽  
Chantelle White ◽  
...  
Keyword(s):  
T Cells ◽  
Cd4 T Cells ◽  
Protective Immunity ◽  
Granzyme B ◽  
Antigen Specificity ◽  
Functional Potential ◽  
Membrane Envelope ◽  
Ifn Γ ◽  
Human Coronaviruses ◽  
Repeated Infections

Abstract Repeated infections with endemic human coronaviruses are thought to reflect lack of long-lasting protective immunity. Here, we evaluate circulating human CD4 T cells collected prior to 2020 for reactivity towards hCoV spike proteins, probing for the ability to produce IFN-γ, IL-2 or granzyme B. We find robust reactivity to spike-derived epitopes, comparable to influenza, but highly variable abundance and functional potential across subjects, depending on age and viral antigen specificity. To explore the potential of these memory cells to be recruited in SARS-CoV-2 infection, we examined the same subjects for cross-reactive recognition of epitopes from SARS-CoV-2 nucleocapsid, membrane/envelope, and spike. The functional potential of these cross-reactive CD4 T cells was highly variable, with nucleocapsid-specific CD4 T cells, but not spike-reactive cells showing exceptionally high levels of granzyme production upon stimulation. These results are considered in light of recruitment of hCoV-reactive cells into responses of humans to SARS-CoV infections or vaccinations.

scholarly journals Characteristics of seizure frequency among Malaysian children diagnosed with structural– metabolic epilepsy

2012 ◽  
Vol 03 (03) ◽  
pp. 244-250 ◽  
Author(s):  
Muhannad RM Salih ◽  
Mohd Baidi Bahari ◽  
Mohamed Azmi Ahmad Hassali ◽  
Asrul Akmal Shafie ◽  
Omer Qutaiba B Al-lela ◽  
...  
Keyword(s):  
Intellectual Disability ◽  
Developmental Delay ◽  
Seizure Frequency ◽  
Substantial Reduction ◽  
Focal Seizure ◽  
Global Developmental Delay ◽  
Neurology Clinic ◽  
Collection Form ◽  
Metabolic Epilepsy

ABSTRACT Introduction: Seizure-free patients or substantial reduction in seizure frequency are the most important outcome measures in the management of epilepsy. The study aimed to evaluate the patterns of seizure frequency and its relationship with demographics, clinical characteristics, and outcomes. Materials and Methods: A retrospective cohort study was conducted at the Pediatric Neurology Clinic, Hospital Pulau Pinang. Over a period of 6 months, the required data were extracted from the medical records using a pre-designed data collection form. Results: Seizure frequency showed no significant association with patient’s demographics and clinical characteristic. However, significant reduction in seizure frequency from the baseline to the last follow-up visit was only seen in certain subgroups of patients including Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability, and patients with focal seizure. There was no significant association between seizure frequency and rate of adverse events. Polytherapy visits were associated with higher seizure frequency than monotherapy visits (27.97 ± 56.66, 10.94 ± 30.96 attack per month, respectively) (P < 0.001). There was a clear tendency to get antiepileptic drugs used at doses above the recommended range in polytherapy (8.4%) rather than in monotherapy (1.4%) visits (P < 0.001). A significant correlation was found between seizure frequency and number of visits per patient per year (r = 0.450, P < 0.001). Conclusion: Among children with structural–metabolic epilepsy, Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability and patients manifested with focal seizure are more responsive antiepileptic drug therapy than the other subgroups of patients.

scholarly journals Updated Analysis of SWOG-Directed Intergroup Study 0116: A Phase III Trial of Adjuvant Radiochemotherapy Versus Observation After Curative Gastric Cancer Resection

2012 ◽  
Vol 30 (19) ◽  
pp. 2327-2333 ◽  
Author(s):  
Stephen R. Smalley ◽  
Jacqueline K. Benedetti ◽  
Daniel G. Haller ◽  
Scott A. Hundahl ◽  
Norman C. Estes ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Substantial Reduction ◽  
Phase Iii ◽  
R0 Resection ◽  
Second Malignancies ◽  
Adjuvant Radiochemotherapy ◽  
Phase Iii Trial ◽  
Failure Patterns ◽  
Postoperative Radiochemotherapy

Purpose Surgical resection of gastric cancer has produced suboptimal survival despite multiple randomized trials that used postoperative chemotherapy or more aggressive surgical procedures. We performed a randomized phase III trial of postoperative radiochemotherapy in those at moderate risk of locoregional failure (LRF) following surgery. We originally reported results with 4-year median follow-up. This update, with a more than 10-year median follow-up, presents data on failure patterns and second malignancies and explores selected subset analyses. Patients and Methods In all, 559 patients with primaries ≥ T3 and/or node-positive gastric cancer were randomly assigned to observation versus radiochemotherapy after R0 resection. Fluorouracil and leucovorin were administered before, during, and after radiotherapy. Radiotherapy was given to all LRF sites to a dose of 45 Gy. Results Overall survival (OS) and relapse-free survival (RFS) data demonstrate continued strong benefit from postoperative radiochemotherapy. The hazard ratio (HR) for OS is 1.32 (95% CI, 1.10 to 1.60; P = .0046). The HR for RFS is 1.51 (95% CI, 1.25 to 1.83; P < .001). Adjuvant radiochemotherapy produced substantial reduction in both overall relapse and locoregional relapse. Second malignancies were observed in 21 patients with radiotherapy versus eight with observation (P = .21). Subset analyses show robust treatment benefit in most subsets, with the exception of patients with diffuse histology who exhibited minimal nonsignificant treatment effect. Conclusion Intergroup 0116 (INT-0116) demonstrates strong persistent benefit from adjuvant radiochemotherapy. Toxicities, including second malignancies, appear acceptable, given the magnitude of RFS and OS improvement. LRF reduction may account for the majority of overall relapse reduction. Adjuvant radiochemotherapy remains a rational standard therapy for curatively resected gastric cancer with primaries T3 or greater and/or positive nodes.

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