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1.
PLoS One ; 16(3): e0247797, 2021.
Article in English | MEDLINE | ID: covidwho-1605332

ABSTRACT

Since the initial identification of the novel coronavirus SARS-CoV-2 in December of 2019, researchers have raced to understand its pathogenesis and begun devising vaccine and treatment strategies. An accurate understanding of the body's temporal immune response against SARS-CoV-2 is paramount to successful vaccine development and disease progression monitoring. To provide insight into the antibody response against SARS-CoV-2, plasma samples from 181 PCR-confirmed COVID-19 patients collected at various timepoints post-symptom onset (PSO) were tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies via lateral flow. Additionally, 21 donors were tracked over time to elucidate patient-specific immune responses. We found sustained levels of anti-SARS-CoV-2 antibodies past 130 days PSO, with 99% positivity observed at 31-60 days PSO. By 61-90 days PSO, the percentage of IgM-/IgG+ results were nearly equal to that of IgM+/IgG+ results, demonstrating a shift in the immune response with a decrease in IgM antibody levels. Results from this study not only provide evidence that the antibody response to COVID-19 can persist for over 4 months, but also demonstrates the ability of Easy Check™ to monitor seroconversion and antibody response of patients. Easy Check was sufficiently sensitive to detect antibodies in patient samples as early as 1-4 days PSO with 86% positivity observed at 5-7 days PSO. Further studies are required to determine the longevity and efficacy of anti-SARS-CoV-2 antibodies, and whether they are protective against re-infection.


Subject(s)
Antibodies, Viral/blood , COVID-19/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/immunology , COVID-19 Serological Testing/instrumentation , COVID-19 Serological Testing/methods , Equipment Design , Female , Humans , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Longitudinal Studies , Male , Middle Aged , SARS-CoV-2/isolation & purification , Young Adult
2.
Front Immunol ; 12: 793191, 2021.
Article in English | MEDLINE | ID: covidwho-1608200

ABSTRACT

Purpose: To compare SARS-CoV-2 antigen-specific antibody production and plasma neutralizing capacity against B.1 wild-type-like strain, and Gamma/P.1 and Delta/B.1.617.2 variants-of-concern, in subjects with different Covid-19 disease and vaccination histories. Methods: Adult subjects were: 1) Unvaccinated/hospitalized for Covid-19; 2) Covid-19-recovered followed by one BNT162b2 vaccine dose; and 3) Covid-19-naïve/2-dose BNT162b2 vaccinated. Multiplex Luminex® immunoassays measured IgG, IgA, and IgM plasma levels against SARS-CoV-2 receptor-binding domain (RBD), spike-1 (S), and nucleocapsid proteins. Neutralizing activity was determined in Vero E6 cytopathic assays. Results: Maximum anti-RBD IgG levels were similar in Covid-19­recovered individuals 8‒10 days after single-dose vaccination and in Covid-19-naïve subjects 7 days after 2nd vaccine dosing; both groups had ≈2­fold higher anti-RBD IgG levels than Unvaccinated/Covid-19 subjects tracked through 2 weeks post-symptom onset. Anti-S IgG expression patterns were similar to RBD within each group, but with lower signal strengths. Viral antigen-specific IgA and IgM levels were more variable than IgG patterns. Anti-nucleocapsid immunoglobulins were not detected in Covid-19-naïve subjects. Neutralizing activity against the B.1 strain, and Gamma/P.1 and Delta/B.1.617.2 variants, was highest in Covid­19-recovered/single-dose vaccinated subjects; although neutralization against the Delta variant in this group was only 26% compared to B.1 neutralization, absolute anti-Delta titers suggested maintained protection. Neutralizing titers against the Gamma and Delta variants were 33‒77% and 26‒67%, respectively, versus neutralization against the B.1 strain (100%) in the three groups. Conclusion: These findings support SARS-CoV-2 mRNA vaccine usefulness regardless of Covid-19 history, and confirm remarkable protection provided by a single vaccine dose in people who have recovered from Covid-19.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/immunology , Immunoglobulin Isotypes/immunology , SARS-CoV-2/immunology , Adult , Aged , Aged, 80 and over , Animals , COVID-19/virology , Chlorocebus aethiops , Female , Humans , Immunoassay/methods , Immunoglobulin A/blood , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin Isotypes/blood , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Middle Aged , SARS-CoV-2/genetics , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/immunology , Spike Glycoprotein, Coronavirus/metabolism , Vaccination/methods , Vero Cells
3.
PLoS One ; 17(1): e0262162, 2022.
Article in English | MEDLINE | ID: covidwho-1605852

ABSTRACT

Analysis of convalescent plasma derived from individuals has shown that IgG3 has the most important role in binding to SARS-CoV-2 antigens; however, this has not yet been confirmed in large studies, and the link between binding and neutralization has not been confirmed. By analyzing plasma pools consisting of 247-567 individual convalescent donors, we demonstrated the binding of IgG3 and IgM to Spike-1 protein and the receptor-binding domain correlates strongly with viral neutralization in vitro. Furthermore, despite accounting for only approximately 12% of total immunoglobulin mass, collectively IgG3 and IgM account for approximately 80% of the total neutralization. This may have important implications for the development of potent therapies for COVID-19, as it indicates that hyperimmune globulins or convalescent plasma donations with high IgG3 concentrations may be a highly efficacious therapy.


Subject(s)
Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/blood , COVID-19/immunology , Convalescence , Immunoglobulin G/immunology , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , Chlorocebus aethiops , Enzyme-Linked Immunosorbent Assay , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Immunoglobulin M/immunology , SARS-CoV-2/physiology , Vero Cells
4.
Viruses ; 13(12)2021 12 20.
Article in English | MEDLINE | ID: covidwho-1580419

ABSTRACT

A microarray-based assay to detect IgG and IgM antibodies against betacoronaviruses (SARS-CoV-2, SARS, MERS, OC43, and HKU1), other respiratory viruses and type I interferons (IFN-Is) was developed. This multiplex assay was applied to track antibody cross-reactivity due to previous contact with similar viruses and to identify antibodies against IFN-Is as the markers for severe COVID-19. In total, 278 serum samples from convalescent plasma donors, COVID-19 patients in the intensive care unit (ICU) and patients who recovered from mild/moderate COVID-19, vaccine recipients, prepandemic and pandemic patients with autoimmune endocrine disorders, and a heterogeneous prepandemic cohort including healthy individuals and chronically ill patients were analyzed. The anti-SARS-CoV-2 microarray results agreed well with the ELISA results. Regarding ICU patients, autoantibodies against IFN-Is were detected in 10.5% of samples, and 10.5% of samples were found to simultaneously contain IgM antibodies against more than two different viruses. Cross-reactivity between IgG against the SARS-CoV-2 nucleocapsid and IgG against the OC43 and HKU1 spike proteins was observed, resulting in positive signals for the SARS-CoV-2 nucleocapsid in prepandemic samples from patients with autoimmune endocrine disorders. The presence of IgG against the SARS-CoV-2 nucleocapsid in the absence of IgG against the SARS-CoV-2 spike RBD should be interpreted with caution.


Subject(s)
Antibodies, Viral/immunology , Interferon Type I/immunology , SARS-CoV-2/immunology , Viruses/immunology , Antibodies, Viral/blood , Antigens, Viral/immunology , Autoantibodies/blood , Autoantibodies/immunology , COVID-19/immunology , COVID-19 Serological Testing , Cross Reactions , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Protein Array Analysis , Respiratory Tract Diseases/immunology , Respiratory Tract Diseases/virology , Viruses/classification
5.
Int Immunopharmacol ; 103: 108491, 2022 Feb.
Article in English | MEDLINE | ID: covidwho-1587489

ABSTRACT

To better understand the immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in individuals with COVID-19, it is important to investigate the kinetics of the antibody responses and their associations with the clinical course in different populations, since there seem to be considerable differences between Western and Asian populations in the clinical features and spread of COVID-19. In this study, we serially measured the serum titers of IgM, IgG and IgA antibodies generated against the nucleocapsid protein (NCP), S1 subunit of the spike protein (S1), and receptor-binding domain in the S1 subunit (RBD) of SARS-CoV-2 in Japanese individuals with COVID-19. Among the IgM, IgG, and IgA antibodies, IgA antibodies against all of the aforementioned viral proteins were the first to appear after the infection, and IgG and/or IgA seroconversion often preceded IgM seroconversion. In regard to the timeline of the antibody responses to the different viral proteins (NCP, S1 and RBD), IgA against NCP appeared than IgA against S1 or RBD, while IgM and IgG against S1 appeared earlier than IgM/IgG against NCP or RBD. The IgG responses to all three viral proteins and responses of all three antibody classes to S1 and RBD were sustained for longer durations than the IgA/IgM responses to all three viral proteins and responses of all three antibody classes to NCP, respectively. The seroconversion of IgA against NCP occurred later and less frequently in patients with mild COVID-19. These results suggest possible differences in the antibody responses to SARS-CoV-2 antigens between the Japanese and Western populations.


Subject(s)
COVID-19/epidemiology , COVID-19/immunology , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2 , Antibody Formation , Humans , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Japan/epidemiology , Japan/ethnology , Seroconversion , Viral Proteins/immunology
6.
Microbiol Spectr ; 9(3): e0133021, 2021 12 22.
Article in English | MEDLINE | ID: covidwho-1583201

ABSTRACT

"Testing Denmark" is a national, large-scale, epidemiological surveillance study of SARS-CoV-2 in the Danish population. Between September and October 2020, approximately 1.3 million people (age >15 years) were randomly invited to fill in an electronic questionnaire covering COVID-19 exposures and symptoms. The prevalence of SARS-CoV-2 antibodies was determined by point-of care rapid test (POCT) distributed to participants' home addresses. In total, 318,552 participants (24.5% invitees) completed the study and 2,519 (0.79%) were seropositive. Of the participants with a prior positive PCR test (n = 1,828), 29.1% were seropositive in the POCT. Although seropositivity increased with age, participants 61 years and over reported fewer symptoms and were tested less frequently. Seropositivity was associated with physical contact with SARS-CoV-2 infected individuals (risk ratio [RR] 7.43, 95% CI: 6.57-8.41), particular in household members (RR 17.70, 95% CI: 15.60-20.10). A greater risk of seropositivity was seen in home care workers (RR 2.09, 95% CI: 1.58-2.78) compared to office workers. A high degree of adherence with national preventive recommendations was reported (e.g., >80% use of face masks), but no difference were found between seropositive and seronegative participants. The seroprevalence result was somewhat hampered by a lower-than-expected performance of the POCT. This is likely due to a low sensitivity of the POCT or problems reading the test results, and the main findings therefore relate to risk associations. More emphasis should be placed on age, occupation, and exposure in local communities. IMPORTANCE To date, including 318,522 participants, this is the largest population-based study with broad national participation where tests and questionnaires have been sent to participants' homes. We found that more emphasis from national and local authorities toward the risk of infection should be placed on age of tested individuals, type of occupation, as well as exposure in local communities and households. To meet the challenge that broad nationwide information can be difficult to gather. This study design sets the stage for a novel way of conducting studies. Additionally, this study design can be used as a supplementary model in future general test strategy for ongoing monitoring of COVID-19 immunity in the population, both from past infection and from vaccination against SARS-CoV-2, however, with attention to the complexity of performing and reading the POCT at home.


Subject(s)
COVID-19/diagnosis , COVID-19/epidemiology , SARS-CoV-2 , Adult , Antibodies, Viral , COVID-19/immunology , Denmark , Female , Humans , Immunity , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Odds Ratio , Point-of-Care Testing , Population Surveillance , Prevalence , SARS-CoV-2/isolation & purification , Seroepidemiologic Studies , Surveys and Questionnaires
7.
Ann Med ; 53(1): 34-42, 2021 12.
Article in English | MEDLINE | ID: covidwho-1574894

ABSTRACT

BACKGROUND: Studies have demonstrated the diagnostic efficiency of antibody testing in COVID-19 infection. There is limited data on the IgM/IgG changes in asymptomatic and discharged patients with reoccurring positive nucleic acid test (RPNAT). This study aims to investigate these IgM/IgG changes. METHODS: There were 111 patients with positive nucleic acid test (NAT) and 40 suspected patients enrolled in the study. The serum SARS-CoV-2 specific IgM/IgG antibody levels were retrospectively analysed with the disease progress in asymptomatic and RPNAT patients. RESULTS: The best overall performance was found by combining the IgM, IgG, and CT; 95.1% sensitivity and 75% specificity. This was tested in 111 RT-PCR positive cases. The median IgM and IgG levels were lower in the asymptomatic group compared to the symptomatic group (p < .01). Among 15 RPNAT cases, the IgM levels of the RPNAT group at the time of discharge (IgM2.79, IQR: 0.95-5.37) and retest (IgM 2.35, IQR: 0.88-8.65) were significantly higher than those of the non-reoccurring positive nucleic acid test group (Non-RPNAT) (IgM on discharge: 0.59, IQR: 0.33-1.22, IgG on retest: 0.92, IQR: 0.51-1.58). CONCLUSION: Serum SARS-CoV-2 specific IgM/IgG antibody levels remained at a low level during hospitalisation for asymptomatic patients. Elevated IgM levels may have implications in the identification of RPNAT patients before discharge. Key messages This study determined the IgM/IgG changes in asymptomatic and RPNAT patients. The rate of serum SARS-CoV-2 specific IgM/IgG antibody levels increase in the asymptomatic group was lower than in the symptomatic group during hospitalisation. The IgM level did not decrease significantly at discharge in the RPNAT patients, and was higher than that of the Non-RPNAT group on discharge. These results highlight the importance of timely monitoring of IgM levels to identify RPNAT patients before discharge.


Subject(s)
Antibodies, Viral/blood , Betacoronavirus/isolation & purification , Coronavirus Infections/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Pneumonia, Viral/immunology , COVID-19 , COVID-19 Testing , Case-Control Studies , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Female , Humans , Immunoenzyme Techniques/methods , Male , Pandemics , Retrospective Studies , SARS-CoV-2
8.
J Med Virol ; 93(12): 6582-6587, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544305

ABSTRACT

The purpose of this study was to evaluate the SARS-CoV-2 immunoglobulin M/immunoglobulin G (IgM/IgG) rapid antibody test results in symptomatic patients with COVID-19 and their chest computed tomography (CT) data. A total of 320 patients admitted to our hospital for different durations due to COVID-19 were included in the study. Serum samples were obtained within 0-7 days from COVID-19 patients confirmed by reverse-transcription polymerase chain reaction (RT-PCR) and chest CT scan. According to the SARS-CoV-2 RT-PCR results, the patients included in the study were divided into two groups: PCR positive group (n = 46) and PCR negative group (n = 274). The relationship between chest CT and rapid antibody test results were compared statistically. Of the 320 COVID-19 serum samples, IgM, IgG, and IgM/IgG were detected in 8.4%, 0.3%, and 11.6% within 1 week, respectively. IgG/IgM antibodies were not detected in 79.7% of the patients. In the study, 249 (77.8%) of 320 patients had positive chest CT scans. Four (5.6%) of 71 patients with negative chest CT scans had IgM and two (2.8%) were both IgM/IgG positive. IgM was detected in 23 (9.2%), IgG in one (0.4%), and IgM/IgG in 35 (14%) of chest CT scan positive patients. The rate of CT findings in patients with antibody positivity was found to be significantly higher than those with antibody negativity. The results of the present study show the accurate and equivalent performance of serological antibody assays and chest CT in detecting SARS-CoV-2 within 0-7 days from the onset of COVID19 symptoms. When RT-PCR is not available, we believe that the combination of immunochromatographic test and chest CT scan can increase diagnostic sensitivity for COVID-19.


Subject(s)
Antibodies, Viral/blood , COVID-19 Testing/methods , COVID-19/diagnosis , Reverse Transcriptase Polymerase Chain Reaction/methods , Adolescent , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/diagnostic imaging , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Male , Middle Aged , Radiography, Thoracic , Retrospective Studies , Tomography, X-Ray Computed , Young Adult
9.
J Med Virol ; 93(12): 6544-6550, 2021 12.
Article in English | MEDLINE | ID: covidwho-1544302

ABSTRACT

We developed a rapid and simple magnetic chemiluminescence enzyme immunoassay on the Real Express-6 analyzer, which could simultaneously detect immunoglobulin G and immunoglobulin M antibodies against SARS-CoV-2 virus in human blood within 18 min, and which could be used to detect clinical studies to verify its clinical efficacy. We selected blood samples from 185 COVID-19 patients confirmed by polymerase chain reaction and 271 negative patients to determine the clinical detection sensitivity, specificity, stability, and precision of this method. Meanwhile, we also surveyed the dynamic variance of viral antibodies during SARS-CoV-2 infection. This rapid immunoassay test has huge potential benefits for rapid screening of SARS-CoV-2 infection and may help clinical drug and vaccine development.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Cross Reactions/immunology , Early Diagnosis , Female , Humans , Immunoassay/methods , Luminescent Measurements , Male , Mass Screening/methods , Middle Aged , Polymerase Chain Reaction , Sensitivity and Specificity , Young Adult
10.
J Med Virol ; 93(12): 6506-6511, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1544294

ABSTRACT

Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunoglouilin G (IgG) and immunoglouilin M (IgM) antibodies have been widely used to assist clinical diagnosis. Our previous study reported a discrepancy in SARS-CoV-2 antibody response between male and female coronavirus disease 2019 (COVID-19) patients. However, the duration and discrepancy between ages as well as sexes of SARS-CoV-2 antibody in convalescent COVID-19 patients have not been clarified. In this study, a total of 538 health-examination individuals who were confirmed with SARS-CoV-2 infection a year ago were enrolled. Blood samples were collected and detected for IgM and IgG antibodies. Among these convalescent patients, 12.80% were detected positive for IgM antibodies. The positive rates for IgM antibody were close between sexes: for males, this is 9.17% and for females 13.75%. However, the IgG antibody was detected positive in as much as 82.90% convalescent patients and the positive rates were nearly the same between males (82.57%) and females (82.98%). Besides this, the level of IgM and IgG antibodies showed no difference between male and female convalescent patients. The level of IgG antibodies showed a significant difference between ages. The elder patients (over 35 years old) maintained a higher level of IgG antibody than the younger patients (under or equal 35 years old) after recovering for 1 year. In addition, IgG antibody was more vulnerable to disappear in younger patients than in elder patients. Overall, our study identified over 1-year duration of SARS-CoV-2 antibody and age difference of IgG antibody response in convalescent COVID-19 patients. These findings may provide new insights into long-term humoral immune response, vaccines efficacy and age-based personalized vaccination strategies.


Subject(s)
Antibodies, Viral/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , SARS-CoV-2/immunology , Adult , Age Factors , Aged , COVID-19/immunology , Coronavirus Nucleocapsid Proteins/immunology , Female , Humans , Male , Middle Aged , Phosphoproteins/immunology , Sex Factors , Spike Glycoprotein, Coronavirus/immunology , Young Adult
11.
Front Immunol ; 12: 777103, 2021.
Article in English | MEDLINE | ID: covidwho-1528826

ABSTRACT

Background: Data regarding symptoms in the lactating mother-infant dyad and their immune response to COVID-19 mRNA vaccination during lactation are needed to inform vaccination guidelines. Methods: From a prospective cohort of 50 lactating individuals who received mRNA-based vaccines for COVID-19 (mRNA-1273 and BNT162b2), blood and milk samples were collected prior to first vaccination dose, immediately prior to 2nd dose, and 4-10 weeks after 2nd dose. Symptoms in mother and infant were assessed by detailed questionnaires. Anti-SARS-CoV-2 antibody levels in blood and milk were measured by Pylon 3D automated immunoassay and ELISA. In addition, vaccine-related PEGylated proteins in milk were measured by ELISA. Blood samples were collected from a subset of infants whose mothers received the vaccine during lactation (4-15 weeks after mothers' 2nd dose). Results: No severe maternal or infant adverse events were reported in this cohort. Two mothers and two infants were diagnosed with COVID-19 during the study period before achieving full immune response. PEGylated proteins were not found at significant levels in milk after vaccination. After vaccination, levels of anti-SARS-CoV-2 IgG and IgM significantly increased in maternal plasma and there was significant transfer of anti-SARS-CoV-2-Receptor Binding Domain (anti-RBD) IgA and IgG antibodies to milk. Milk IgA levels after the 2nd dose were negatively associated with infant age. Anti-SARS-CoV-2 IgG antibodies were not detected in the plasma of infants whose mothers were vaccinated during lactation. Conclusions: COVID-19 mRNA vaccines generate robust immune responses in plasma and milk of lactating individuals without severe adverse events reported.


Subject(s)
Antibodies, Viral/immunology , COVID-19 Vaccines/administration & dosage , Lactation/immunology , Milk, Human/immunology , SARS-CoV-2/immunology , Adult , Antibodies, Viral/blood , COVID-19/prevention & control , Female , Humans , Immunoglobulin A/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Immunoglobulin M/blood , Immunoglobulin M/immunology , Infant , Infant, Newborn , Male , Middle Aged
12.
Front Immunol ; 12: 772239, 2021.
Article in English | MEDLINE | ID: covidwho-1528825

ABSTRACT

This contribution explores in a new statistical perspective the antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 141 coronavirus disease 2019 (COVID-19) patients exhibiting a broad range of clinical manifestations. This cohort accurately reflects the characteristics of the first wave of the SARS-CoV-2 pandemic in Italy. We determined the IgM, IgA, and IgG levels towards SARS-CoV-2 S1, S2, and NP antigens, evaluating their neutralizing activity and relationship with clinical signatures. Moreover, we longitudinally followed 72 patients up to 9 months postsymptoms onset to study the persistence of the levels of antibodies. Our results showed that the majority of COVID-19 patients developed an early virus-specific antibody response. The magnitude and the neutralizing properties of the response were heterogeneous regardless of the severity of the disease. Antibody levels dropped over time, even though spike reactive IgG and IgA were still detectable up to 9 months. Early baseline antibody levels were key drivers of the subsequent antibody production and the long-lasting protection against SARS-CoV-2. Importantly, we identified anti-S1 IgA as a good surrogate marker to predict the clinical course of COVID-19. Characterizing the antibody response after SARS-CoV-2 infection is relevant for the early clinical management of patients as soon as they are diagnosed and for implementing the current vaccination strategies.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/blood , Immunoglobulin A/blood , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Adult , Aged , Aged, 80 and over , COVID-19/immunology , Female , HEK293 Cells , Hospitalization , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Young Adult
13.
Bull Exp Biol Med ; 171(2): 230-233, 2021 May.
Article in English | MEDLINE | ID: covidwho-1525548

ABSTRACT

The presence of IgG and IgM antibodies in the venous blood of 76 patients with confirmed COVID-19 infection was determined by ELISA using Russian test systems. Different levels of IgM antibodies to N-protein and receptor binding domain of the Spike protein (RBD) were revealed. The dynamics of IgG antibodies to the whole virion antigen and recombinant antigens showed high values on weeks 4-5 of the disease. The level of IgG antibodies to Nprotein remained low throughout the observation period. The characteristic dynamics of IgG measured using test systems with sorbed whole virion or recombinant spike proteins reflects the duration of the disease.


Subject(s)
Antibodies, Viral/blood , Antigens, Viral/immunology , COVID-19/diagnosis , Coronavirus Nucleocapsid Proteins/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Spike Glycoprotein, Coronavirus/immunology , Antigens, Viral/genetics , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Coronavirus Nucleocapsid Proteins/genetics , Enzyme-Linked Immunosorbent Assay , Humans , Immunity, Humoral , SARS-CoV-2/immunology , SARS-CoV-2/pathogenicity , Spike Glycoprotein, Coronavirus/genetics , Time Factors , Virion/genetics , Virion/immunology
14.
Placenta ; 115: 146-150, 2021 11.
Article in English | MEDLINE | ID: covidwho-1514252

ABSTRACT

There is inadequate screening for SARS-COV-2 during pregnancy. We aimed to determine the impact of maternal and neonatal cord blood SARS-COV-2 antibodies and placental transfer ratios in a region with a low screening plan. We performed a blind study in one of the SARS-CoV-2 epicenters in South America. 32% of pregnant women were serological positive. Importantly, there is an efficient passive immunization of the fetus to SARS-CoV-2. We report high incidence of SARS-CoV-2 infection during pregnancy, which is higher than officially reported. Therefore the need of active immunization to enhance maternal protection and fetal passive immunization.


Subject(s)
COVID-19/epidemiology , Fetal Blood/immunology , Pregnancy Complications, Infectious/epidemiology , SARS-CoV-2/immunology , Adolescent , Adult , Antibodies, Viral/blood , COVID-19/blood , COVID-19/immunology , Ecuador/epidemiology , Female , Fetal Blood/metabolism , Humans , Immunization, Passive/statistics & numerical data , Immunoglobulin G/blood , Immunoglobulin M/blood , Incidence , Infant, Newborn , Infectious Disease Transmission, Vertical/statistics & numerical data , Male , Middle Aged , Pregnancy , Pregnancy Complications, Infectious/blood , Pregnancy Complications, Infectious/immunology , Seroepidemiologic Studies , Young Adult
15.
Allergol Immunopathol (Madr) ; 49(6): 63-66, 2021.
Article in English | MEDLINE | ID: covidwho-1513272

ABSTRACT

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has affected millions of people around the world. This zoonotic-enveloped virus is primarily transmitted through inhalation. Infected people are commonly asymptomatic or manifest mild symptoms, including fever, cough, diarrhea, and fatigue. However, it may lead to severe patterns associated with multiple organ failure in individuals with an impaired immune system. OBJECTIVE: Here we report a 7-year-old girl with hyper-immunoglobulin M (IgM) (HIgM) phenotype, admitted to the hospital emergency department with fever, cough, and pneumonia symptoms because of the COVID-19 infection. Coronavirus infection was confirmed by a positive real-time polymerase chain reaction test. Surprisingly, serum levels of both IgG and IgA of the patient were transiently normalized during the COVID-19 infection when tested prior to the monthly injection of intravenous immunoglobulin. After she recovered from the COVID infection, her immunoglobulin levels returned to the primary stage and she demonstrated HIgM phenotype. CONCLUSION: Since this transient increase in the levels of immunoglobulins was solely observed during the COVID-19 infection, and no other infectious episodes were diagnosed in the patient, clarifying the exact cause would help to understand in a better manner the implications and specification of humoral immunity in patients with primary antibody deficiencies.


Subject(s)
COVID-19/complications , Hyper-IgM Immunodeficiency Syndrome/virology , Child , Female , Humans , Immunoglobulin M/blood
16.
J Korean Med Sci ; 36(43): e294, 2021 Nov 08.
Article in English | MEDLINE | ID: covidwho-1506223

ABSTRACT

BACKGROUND: In Korea, the first community outbreak of coronavirus disease 2019 (COVID-19) occurred in Daegu on February 18, 2020. This study was performed to investigate the prevalence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies in healthcare workers (HCWs) at 6 major hospitals in Daegu. METHODS: Blood specimens of 2,935 HCWs at 6 major hospitals in Daegu from January 2021 to February 2021 were collected. Every specimen was tested for antibody against SARS-CoV-2 using both Elecsys Anti-SARS-CoV-2 electrochemiluminescence immunoassay (Roche Diagnostics, Rotkreuz, Switzerland) and R-FIND COVID-19 IgG/M/A enzyme-linked immunosorbent assay kit (SG medical Inc., Seoul, Korea) as screening tests. If 1 or more of these screening test results was positive, 2 additional antibody tests were performed using Abbott Anti-SARS-CoV-2 IgG assay (Abbott, Abbott Park, IL, USA) and cPass SARS-CoV-2 Neutralization Antibody Detection Kit (GenScript USA Inc., Piscataway, NJ, USA). If 2 or more of the total 4 test results were positive, it was determined as positive for the antibody against SARS-CoV-2. RESULTS: According to the criteria of SARS-CoV-2 antibody positivity determination, 12 subjects were determined as positive. The overall positive rate of the SARS-CoV-2 antibody was 0.41% (12/2,935). Of the 12 subjects determined as positive, 7 were diagnosed with COVID-19, and the remaining 5 were nondiagnosed cases of COVID-19. CONCLUSION: In early 2021, the overall seroprevalence of SARS-CoV-2 antibody among HCW located in Daegu was 0.41%, and 0.17% excluding COVID-19 confirmed subjects. These results were not particularly high compared with the general public and were much lower than HCWs in other countries.


Subject(s)
Antibodies, Viral/blood , COVID-19/diagnosis , COVID-19/immunology , Health Personnel/statistics & numerical data , Immunoglobulin G/blood , Adult , Aged , Antibodies, Neutralizing , Antibody Specificity , COVID-19/epidemiology , Enzyme-Linked Immunosorbent Assay , Female , Hospitals , Humans , Immunoglobulin A/blood , Immunoglobulin M/blood , Male , Middle Aged , Prevalence , Republic of Korea/epidemiology , SARS-CoV-2
17.
Monoclon Antib Immunodiagn Immunother ; 40(5): 210-218, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1483363

ABSTRACT

The novel coronavirus disease (COVID-19), known as severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), exhibits a strong human-to-human transmission infectivity and could cause acute respiratory infections. Therefore, simple and rapid serological testing is urgently needed to recognize positive cases. In this study, a point-of-care serological test based on lateral flow immunoassay (LFIA) was developed and its application for the simultaneous detection of IgM/IgG antibodies against SARS-CoV-2 was evaluated. The recombinant SARS-CoV-2 antigens were conjugated to the produced colloidal gold nanoparticles and used as the detection reagent. This test required only 10-15 minutes to achieve simultaneous qualitative detection of IgM/IgG antibodies specific to SARS-CoV-2 in 20 µL of serum or plasma samples. The clinical performance and reliability of the assay were evaluated by performing the test with 60 samples and comparing the results of these tests with those obtained via real-time polymerase chain reaction. The sensitivity and specificity of our assay were defined to be 90% and 96.6%, respectively. The presented LFIA was sufficiently sensitive and accurate to be used for the rapid diagnosis of coronavirus disease 2019 in laboratories or in patient care settings, particularly in emergency conditions, in which many samples require to be evaluated on time.


Subject(s)
Immunoassay/methods , Immunoglobulin G/blood , Immunoglobulin M/blood , Metal Nanoparticles/chemistry , SARS-CoV-2/immunology , Antibodies, Viral/blood , COVID-19 Serological Testing/methods , Colloids/chemistry , Cross Reactions , Gold , Humans , Immunoassay/instrumentation , Reagent Strips , Sensitivity and Specificity
18.
PLoS Negl Trop Dis ; 15(10): e0009754, 2021 10.
Article in English | MEDLINE | ID: covidwho-1477512

ABSTRACT

Brazil presents one of the highest COVID-19 death tolls in the world. The initial SARS-CoV-2 epicenter was São Paulo city. As of 2019, the homeless population of São Paulo city was estimated at 24,344 individuals, the largest national homeless population. The present study aimed to concomitantly assess the molecular and serological prevalence and associated risk factors of SARS-CoV-2 infection in a homeless population and related shelter workers from a day-shelter. Serum samples, nasopharyngeal and oropharyngeal swabs of persons who are homeless and shelter workers collected from August 25th to 27th, 2020 were tested for the presence of anti-SARS-CoV-2 IgM and IgG antibodies by ELISA and SARS-CoV-2 RNA by RT-qPCR, respectively. All swab samples tested negative by RT-qPCR. Seropositivity of IgM and IgG was 5/203 (2.5%) and 111/203 (54.7%) in persons who are homeless, and 5/87 (5.7%) and 41/87 (47.1%) in shelter workers, respectively, with no statistical differences between groups. The high seroprevalence found herein indicates early environmental and urban spreading of SARS-CoV-2, associated with sociodemographic and economic vulnerability.


Subject(s)
Antibodies, Viral/blood , COVID-19/epidemiology , Homeless Persons , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Aged, 80 and over , Brazil/epidemiology , Cross-Sectional Studies , Female , Humans , Immunoglobulin G/blood , Immunoglobulin M/blood , Male , Middle Aged , Seroepidemiologic Studies , Young Adult
19.
EBioMedicine ; 72: 103615, 2021 Oct.
Article in English | MEDLINE | ID: covidwho-1466279

ABSTRACT

BACKGROUND: Most children and youth develop mild or asymptomatic disease during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, a very small number of patients suffer severe Coronavirus induced disease 2019 (COVID-19). The reasons underlying these different outcomes remain unknown. METHODS: We analyzed three different cohorts: children with acute infection (n=550), convalescent children (n=138), and MIS-C (multisystem inflammatory syndrome in children, n=42). IgG and IgM antibodies to the spike protein of SARS-CoV-2, serum-neutralizing activity, plasma cytokine levels, and the frequency of circulating Follicular T helper cells (cTfh) and plasmablasts were analyzed by conventional methods. FINDINGS: Fifty-eight percent of the children in the acute phase of infection had no detectable antibodies at the time of sampling while a seronegative status was found in 25% and 12% of convalescent and MIS-C children, respectively. When children in the acute phase of the infection were stratified according disease severity, we found that contrasting with the response of children with asymptomatic, mild and moderate disease, children with severe COVID-19 did not develop any detectable response. A defective antibody response was also observed in the convalescent cohort for children with severe disease at the time of admission. This poor antibody response was associated to both, a low frequency of cTfh and a high plasma concentration of inflammatory cytokines. INTERPRETATION: A weak and delayed kinetic of antibody response to SARS-CoV-2 together with a systemic pro-inflammatory profile characterize pediatric severe COVID-19. Because comorbidities are highly prevalent in children with severe COVID-19, further studies are needed to clarify their contribution in the weak antibody response observed in severe disease. FUNDING: National Agency for Scientific and Technological Promotion from Argentina (IP-COVID-19-0277 and PMO-BID-PICT2018-2548).


Subject(s)
Antibodies, Viral/blood , Antibody Formation , COVID-19/complications , COVID-19/immunology , Immunoglobulin G/blood , Immunoglobulin M/blood , Systemic Inflammatory Response Syndrome/immunology , Argentina , COVID-19/blood , Child , Child, Preschool , Cytokines/blood , Female , Humans , Infant , Male , SARS-CoV-2/immunology , Systemic Inflammatory Response Syndrome/blood
20.
Eur J Clin Microbiol Infect Dis ; 40(12): 2669-2676, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1460345

ABSTRACT

The humoral and cellular immunity of convalescent COVID-19 patients is involved in pathogenesis and vaccine immunity. In this study, through CoV-psV neutralization assay and IFN-γ ELISpot testing in 30 cases of COVID-19 patients after 9 months post-SARS-CoV-2 infection, it found that the ratio of memory/naive CD4+ T lymphocytes cells and levels of anti-SARS-CoV-2-IgM and RBD-IgM were slightly but significantly higher in COVID-19 severe convalescent patients than that in non-severe patients. The specific cellular and humoral immunity against SARS-CoV-2 were detectable, regardless of the severity of the disease in the acute phase. This information may help understanding the immune status after SARS-CoV-2 infection.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , COVID-19/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Viral/blood , COVID-19/blood , Enzyme-Linked Immunospot Assay , Female , Humans , Immunity, Cellular , Immunity, Humoral , Immunoglobulin M/blood , Male , Middle Aged , SARS-CoV-2/genetics , SARS-CoV-2/physiology
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