Persistence of SARS-CoV-2-Specific Antibodies for 13 Months after Infection

Background: Dynamics of antibody responses were investigated after a SARS-CoV-2 outbreak in a private company during the first wave of the pandemic. Methods: Workers of a sewing company (Lithuania) with known SARS-CoV-2 RT-PCR result during the outbreak (April 2020) were invited to participate in the study. Virus-specific IgG and IgM were monitored 2, 6 and 13 months after the outbreak via rapid IgG/IgM serological test and SARS-CoV-2 S protein-specific IgG ELISA. Results: Six months after the outbreak, 95% (CI 86–99%) of 59 previously infected individuals had virus-specific antibodies irrespective of the severity of infection. One-third of seropositive individuals had virus-specific IgM along with IgG indicating that IgM may persist for 6 months. Serological testing 13 months after the outbreak included 47 recovered individuals that remained non-vaccinated despite a wide accessibility of COVID-19 vaccines. The seropositivity rate was 83% (CI 69–91%) excluding one case of confirmed asymptomatic reinfection in this group. Between months 6 and 13, IgG levels either declined or remained stable in 31 individual and increased in 7 individuals possibly indicating an exposure to SARS-CoV-2 during the second wave of the pandemic. Conclusions: Detectable levels of SARS-CoV-2-specific antibodies persist up to 13 months after infection for the majority of the cases.

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Serological surveys in Reunion Island of the first hospitalized patients revealed that long-lived immunoglobulin G antibodies specific against SARS-CoV2 virus are rapidly vanishing in severe cases

10.1101/2020.05.25.20112623 ◽

2020 ◽

Cited By ~ 2

Author(s):

Dobi Anthony ◽

Frumence Etienne ◽

Lalarizo Rakoto Mahary ◽

Lebeau Grégorie ◽

Vagner Damien ◽

...

Keyword(s):

Protein S ◽

Severe Form ◽

Hospitalized Patients ◽

Serological Testing ◽

Rt Pcr ◽

Icu Patients ◽

Cell Responses ◽

Conventional Elisa ◽

Specific Igg ◽

Kinetics Of

Both cellular and humoral immunities are critically important to control COVID19 infection but little is known about the kinetics of those responses and, in particular, in patients who will go on to develop a severe form of the disease over several weeks. We herein report the first set of data of our prospective cohort study of 90 hospitalized cases. Serological surveys were thoroughly performed over 2 month period by assessing IgG and IgM responses by immunofluorescence, immunoblot, Western blot and conventional ELISA using clinical RUN isolates of SARS-CoV-2 immobilized on 96 well plates. While the IgM and, unexpectedly, the IgG responses were readily detected early during the course of the disease (5-7 days post-first symptoms), our results (n=3-5 and over the full dilution set of the plasma 1/200 to 1/12800) demonstrated a significant decrease (over 2.5-fold) of IgG levels in severe (ICU) hospitalized patients (exemplified in patient 1) by WB and ELISA. In contrast, mild non-ICU patients had a steady and yet robust rise in their specific IgG levels against the virus. Interestingly, both responses (IgM and IgG) were initially against the nucleocapsid (50kDa band on the WB) and spreading to other major viral protein S and domains (S1 and S2. In conclusion, serological testing may be helpful for the diagnosis of patients with negative RT-PCR results and for the identification of asymptomatic cases. Moreover, medical care and protections should be maintained particularly for recovered patients (severe cases) who may remain at risk of relapsing or reinfection. Experiments to ascertain T cell responses but although their kinetics overtime are now highly warranted. All in all, these studies will help to delineate the best routes for vaccination.

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The Slower Antibody Response in Myelofibrosis Patients after Two Doses of mRNA SARS-CoV-2 Vaccine Calls for a Third Dose

Biomedicines ◽

10.3390/biomedicines9101480 ◽

2021 ◽

Vol 9 (10) ◽

pp. 1480

Author(s):

Fabio Fiorino ◽

Anna Sicuranza ◽

Annalisa Ciabattini ◽

Adele Santoni ◽

Gabiria Pastore ◽

...

Keyword(s):

Healthy Subjects ◽

Vaccine Dose ◽

Antibody Responses ◽

Inhibition Activity ◽

Specific Antibodies ◽

Slow Kinetics ◽

Binding Inhibition ◽

Specific Igg ◽

The Impact ◽

Kinetics Of

Immunization with mRNA SARS-CoV-2 vaccines has been highly recommended and prioritized in fragile subjects, including patients with myelofibrosis (MF). Available data on the vaccine immune response developed by MF patients and the impact of ruxolitinib treatment are still too fragmented to support an informed decision on a third dose for this category of subjects. Here, we show that 76% of MF patients develop spike-specific IgG after the second mRNA SARS-CoV-2 vaccine dose, but the response has a slower kinetics compared to healthy subjects, suggesting a reduced capability of their immune system to promptly react to vaccination. A reduced ACE2/RBD binding inhibition activity of spike-specific antibodies was also observed, especially in ruxolitinib-treated patients. Our results, showing slow kinetics of antibody responses in MF patients following vaccination with mRNA SARS-CoV-2 vaccines, support the need for a third vaccine dose.

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Rapid response flow cytometric assay for the detection of antibody responses to SARS-CoV-2

10.1101/2020.05.09.20091447 ◽

2020 ◽

Cited By ~ 1

Author(s):

Dennis Lapuente ◽

Clara Maier ◽

Pascal Irrgang ◽

Julian Huebner ◽

Sophia Antonia Peter ◽

...

Keyword(s):

Antibody Responses ◽

Quantitative Detection ◽

Converting Enzyme ◽

Flow Cytometric Assay ◽

Angiotensin Converting Enzyme 2 ◽

Specific Antibodies ◽

Diagnostic Assays ◽

Flow Cytometric ◽

External Standard ◽

Specific Igg

SARS-CoV-2 has emerged as a previously unknown zoonotic coronavirus that spread worldwide causing a serious pandemic. While reliable nucleic acid-based diagnostic assays were rapidly available, there exists only a limited number of validated serological assays. Here, we evaluated a novel flow cytometric approach based on antigen-expressing HEK 293T cells to assess spike-specific IgG and IgM antibody responses. Analyses of 201 pre-COVID-19 sera proved a high assay specificity in comparison to commercially available CLIA and ELISA systems, while also revealing the highest sensitivity in specimens from PCR-confirmed SARS-CoV-2 infected patients. Additionally, a soluble Angiotensin-Converting-Enzyme 2 (ACE-2) variant was established as external standard to quantify spike-specific antibody responses on different assay platforms. In conclusion, our newly established flow cytometric assay allows sensitive and quantitative detection of SARS-CoV-2-specific antibodies, which can be easily adopted in different laboratories and does not rely on external supply of assay kits.

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Detection Of Equine Arteritis Virus In The Semen Of Stallions In The Republic Of Serbia

Acta veterinaria ◽

10.1515/acve-2015-0047 ◽

2015 ◽

Vol 65 (4) ◽

pp. 557-567 ◽

Cited By ~ 2

Author(s):

Sava Lazić ◽

Diana Lupulović ◽

Vladimir Polaček ◽

Miroslav Valčić ◽

Gospava Lazić ◽

...

Keyword(s):

Viral Genome ◽

Neutralization Test ◽

Equine Arteritis Virus ◽

Serological Testing ◽

Rt Pcr ◽

High Seroprevalence ◽

Chain Reaction ◽

Specific Antibodies ◽

Polymerase Chain ◽

The Republic

AbstractThe results on serological testing of blood sera from stallions and mares used for breeding and the presence of the viral genome of Equine Arteritis Virus (EAV) in stallion semen are presented. The blood and semen samples were taken from a horse stable on the territory of the Republic of Serbia during 2012, 2013 and 2014. Detection of anti-EAV specific antibodies in blood sera was performed by the virus neutralization test (VNT), and identification of EAV genome RNA in stallion semen was done by reverse-transcriptase polymerase chain reaction (RT-PCR). In 2012, high seroprevalence of EAV was detected in the investigated stable. In total, 45% and 65 % of stallions and mares reacted positive, respectively, and the antibody titre values ranged between 2 and 10 log2. High seroprevalence was confirmed in the same animals again in 2013. Out of two stallions tested semen samples in 2013, the viral genome was detected by RT-PCR in 3 examined semen samples from a seropositive stallion, while EAV was not detected in 3 semen samples of a seronegative stallion. During 2014, 11 semen samples were collected from two seropositive stallions. Again, the presence of EAV was confirmed by RT-PCR in all 8 semen samples originating from the same stallion with the EAV genome positive semen result in 2013, whereas the virus was not detected in semen samples originating from the second anti-EAV antibody positive stallion. The presence of EAV-specific antibodies was confirmed in the blood sera of the mares inseminated with the semen of seropositive stallions in 2012 and 2013.

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The slower antibody response in myelofibrosis patients after two doses of mRNA SARS-CoV-2 vaccine calls for a third dose

10.1101/2021.09.21.21263627 ◽

2021 ◽

Author(s):

Fabio Fiorino ◽

Anna Sicuranza ◽

Annalisa Ciabattini ◽

Adele Santoni ◽

Gabiria Pastore ◽

...

Keyword(s):

Healthy Subjects ◽

Vaccine Dose ◽

Binding Activity ◽

Antibody Responses ◽

Specific Antibodies ◽

Risk Of Mortality ◽

Specific Igg ◽

Open Question ◽

The Impact ◽

Slow Kinetic

Immunization with mRNA SARS-CoV-2 vaccines has been highly recommended and prioritized in fragile categories with higher risk of mortality after COVID-19 disease compared to healthy people, including patients with myelofibrosis (MF). Available data on the vaccine immune re-sponse developed by MF patients, and the impact of the treatment with the inhibitor of JAK-STAT signaling ruxolitimib, are still fragmented to support an informed decision for a third dose for this category of subjects. Here, we show that 76% of MF patients develop spike-specific IgG after the second vaccine dose, but the response has a slower kinetic compared to healthy subjects, suggesting a reduced capability of their immune system to promptly react to vaccina-tion. A reduced ACE2/RBD inhibition binding activity of spike-specific antibodies was also ob-served, especially in ruxolitimib treated patients. Our results contribute to answer the open question on the induction of the antibody responses in MF patients following vaccination with COVID-19 mRNA vaccines, showing a slow kinetic that support the need for a third dose of SARS-CoV-2 mRNA vaccines.

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Tear antibodies to SARS-CoV-2: implications for transmission

10.1101/2021.08.02.21261479 ◽

2021 ◽

Author(s):

Kevin John Selva ◽

Samantha K Davis ◽

Ebene R Haycroft ◽

Wen Shi Lee ◽

Ester Lopez ◽

...

Keyword(s):

Ocular Surface ◽

Post Infection ◽

Antibody Responses ◽

Healthy Controls ◽

Igg Antibodies ◽

Neutralising Antibodies ◽

Specific Antibodies ◽

Route Of Transmission ◽

Specific Igg ◽

Specific Igg Antibodies

Objectives SARS-CoV-2 can be transmitted by aerosols and the ocular surface may be an important route of transmission. Little is known about protective antibody responses to SARS-CoV-2 in tears after infection or vaccination. We analysed SARS-CoV-2 specific IgG and IgA responses in human tears after either COVID-19 infection or vaccination. Methods We recruited 16 subjects with COVID-19 infection an average of 7 months previously and 15 subjects before and 2 weeks after Comirnaty (Pfizer-BioNtech) vaccination. Plasma, saliva and basal tears were collected. Pre-pandemic plasma, saliva and basal tears from 11 individuals were included as healthy controls. Antibody responses to 5 SARS-CoV-2 antigens were measured via multiplex. Results IgG antibodies to Spike and Nucleoprotein were detected in tears, saliva and plasma from subjects with prior SARS-CoV-2 infection in comparison to uninfected controls. While RBD-specific antibodies were detected in plasma, minimal RBD-specific antibodies were detected in tears and saliva. In contrast, high levels of IgG antibodies to Spike and RBD, but not Nucleoprotein, were induced in tears, saliva and plasma of subjects receiving 2 doses of the Comirnaty vaccine. Increased levels of IgA1 and IgA2 antibodies to SARS-CoV-2 antigens were detected in plasma following infection or vaccination, but were unchanged in tears and saliva. Conclusion Both infection and vaccination induce SARS-CoV-2-specific IgG antibodies in tears. RBD-specific IgG antibodies in tears were induced by vaccination but were not present 7 months post-infection. This suggests neutralising antibodies may be low in the tears late following infection.

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Changes in SARS-CoV-2 Antibody Responses Impact the Estimates of Infections in Population-Based Seroprevalence Studies

10.1101/2020.07.14.20153536 ◽

2020 ◽

Cited By ~ 8

Author(s):

Craig Fenwick ◽

Antony Croxatto ◽

Alix T. Coste ◽

Florence Pojer ◽

Cyril Andre ◽

...

Keyword(s):

General Population ◽

Acute Infection ◽

Population Based ◽

Antibody Responses ◽

Igg Antibodies ◽

Rt Pcr ◽

Igg Antibody ◽

S Protein ◽

N Protein ◽

Total Cohort

We have determined SARS-CoV-2-specific antibody responses in a cohort of 96 individuals with acute infection and in 578 individuals enrolled in a seroprevalence population study in Switzerland including three groups, i.e. subjects with previous RT-PCR confirmed SARS-CoV-2 infections (n=90), positive patient contacts (n=177) and random selected subjects (n=311). SARS-CoV-2 antibody responses specific to the Spike (S), in the monomeric and native trimeric forms, and/or the nucleocapsid (N) proteins were equally sensitive in the acute infection phase. Interestingly, as compared to anti-S antibody responses, those against the N protein appear to wane in the post-infection and substantially underestimated the proportion of SARS-CoV-2 infections in the groups of patient positive contacts, i.e. 10.9 to 32.2% reduction and in the random selected general population, i.e. up to 45% reduction. The overall reduction in seroprevalence targeting only anti-N IgG antibodies for the total cohort ranged from 9.4 to 31%. Of note, the use of the S protein in its native trimer form was more sensitive as compared to monomeric S proteins. These results indicate that the assessment of anti-S IgG antibody responses against the native trimeric S protein should be implemented to estimate SARS-CoV-2 infections in population-based seroprevalence studies.

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Surface Engineering of Recombinant RNA Coliphage Qβ to Display gp41 MembraneProximal External-Region Epitopes from HIV-1

Journal of Clinical & Experimental Immunology ◽

10.33140/jcei.002.01.04 ◽

2017 ◽

Vol 2 (1) ◽

Keyword(s):

Immune System ◽

Coat Protein ◽

Antibody Responses ◽

Igg Antibody ◽

External Region ◽

Specific Antibodies ◽

Infected People ◽

Specific Igg ◽

Minor Coat Protein ◽

Hiv 1

Introduction: The membrane proximal external region (MPER) of HIV-1 envelope glycoprotein-41 (gp41) is targeted by several broadly neutralizing antibodies whose conserved linear epitopes are promising targets for vaccine design. However, a formidable challenge has remained the difficulty to design and deliver MPER based immunogens for the efficient induction of such broadly neutralizing HIV-1 specific antibodies (bnAb). This is mainly because the linear bnAb MPER epitopes are poorly accessible to the immune system. The overall objective of this study therefore was the development of a novel RNA Qβ phage display system not only for monitoring anti-MPER specific antibody responses but equally as potential immunogens in future HIV-1 vaccine designs. Method: To overcome the challenge of effective presentation of MPER to the immune system we have selectively engineered the surface of the RNA coliphage Qβ to expose all MPER bnAb epitopes. Briefly, DNA representing a 50 amino acids consensus region within the HIV-1 gp41 MPER was fused in frame with the minor coat protein A1of the Qβ phage. Three variant MPER expression cassettes were obtained with the MPER cDNA in frame with the minor coat protein A1 gene, including pQβMPER, pQβMPERHis and pQβMPERN. The expression cassettes were used for the production of QβMPER recombinant phages after transformation of E. coli HB101 strain. Antigencity of the phages was assessed with plasma from long standing anti-retroviral naïve HIV-1 infected people from the CIRCB AFRODEC cohort while immunogenicity studies were done in female Balb/c mice. Results: The initial titers of all recombinant phages including QβMPER, QβMPERHis and QβMPERN were 104 plaque forming units/ml (pfu/ml). This was significantly lower (P<0.001) relative to the 108 pfu/ml of wild type phage, but was scaled up to 1014pfu/ml. The fusion of MPER and Qβ genes was confirmed by RT-PCR followed by gel electrophoresis and sequencing. Specific recognition of some reported bnAb epitopes within MPER were confirmed in ELISA using the three recombinant QβMPER phages together with an MPER restrictive peptide as antigens and the bnAb 4E10, Z13e1, 2F5 and 10E8 as antibodies. Next the prevalence of MPER-specific antibodies was determined in plasma from long standing antiretroviral naïve HIV-1 infected participants of the CIRCB AFRODEC cohort. The greater majority (84%) of participants’ plasma showed MPER peptide specific reactivity with anti-MPER specific IgG antibody titers ranging from 200 to 409600 comparative to background IgG antibody titer with the Qβ phage alone as antigen or plasma from seronegative participants. In immunogenicity studies in Balb/c mice the recombinant phages QβMPERN and QβMPERHis induced significantly high Anti-MPER-specific IgG antibody responses (P<0.04) in at least 60 % of mice following three inoculations of each recombinant phage. Conclusion: Thus, these novel recombinantQβMPER phages can be used to monitor MPER-specific immune responses in HIV-1 exposed or infected people. In addition the recombinant QβMPER phages could be used as immunogens either alone as demonstrated here in mice or in combination with other strategies for the induction of MPER specific immunity against HIV-1.

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SARS-CoV-2 IgG antibody responses in rt-PCR-positive cases: first report from India

Access Microbiology ◽

10.1099/acmi.0.000267 ◽

2021 ◽

Vol 3 (10) ◽

Author(s):

Girish Chandra Dash ◽

Debaprasad Parai ◽

Hari Ram Choudhary ◽

Annalisha Peter ◽

Usha Kiran Rout ◽

...

Keyword(s):

Antibody Response ◽

Clinical Utility ◽

Antibody Responses ◽

Serological Testing ◽

Rt Pcr ◽

Serum Samples ◽

Igg Antibody ◽

Significant Difference ◽

The Mean ◽

The Relationship

Introduction. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody responses remain poorly understood and the clinical utility of serological testing is still unclear. Aim. To understand the relationship between the antibody response to SARS-CoV-2 infection and the demographics and cycle threshold (C t) values of confirmed RT-PCR patients. Methodology. A total of 384 serum samples were collected from individuals between 4–6 weeks after confirmed SARS-CoV-2 infection and tested for the development of immunoglobulin class G (IgG) against SARS-CoV-2. The C t values, age, gender and symptoms of the patients were correlated with the development of antibodies. Results. IgG positivity was found to be 80.2 % (95 % CI, 76.2–84.2). Positivity increased with a decrease in the C t value, with the highest (87.6 %) positivity observed in individuals with C t values <20. The mean (±sd) C t values for IgG positives and negatives were 23.34 (±6.09) and 26.72 (±7.031), respectively. No significant difference was found for demographic characteristics such as age and sex and symptoms and antibody response. The current study is the first of its kind wherein we have assessed the correlation of the RT-PCR C t with the development of IgG against SARS-CoV-2. Conclusion. Although C t values might not have any relation with the development of symptoms, they are associated with the antibody response among SARS-CoV-2-infected individuals.

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Optimising triage procedures for patients with cancer needing active anticancer treatment in the COVID-19 era

ESMO Open ◽

10.1136/esmoopen-2020-000885 ◽

2020 ◽

Vol 5 (5) ◽

pp. e000885

Author(s):

Grazia Arpino ◽

Carmine De Angelis ◽

Pietro De Placido ◽

Erica Pietroluongo ◽

Luigi Formisano ◽

...

Keyword(s):

Cancer Treatment ◽

Asymptomatic Patient ◽

Serological Test ◽

University Hospital ◽

Serological Testing ◽

Rt Pcr ◽

Serological Tests ◽

Patients With Cancer ◽

Anticancer Treatment ◽

Active Cancer

BackgroundImmunosuppression induced by anticancer therapy in a COVID-19-positive asymptomatic patient with cancer may have a devastating effect and, eventually, be lethal. To identify asymptomatic cases among patients receiving active cancer treatment, the Federico II University Hospital in Naples performs rapid serological tests in addition to hospital standard clinical triage for COVID-19 infection.MethodsFrom 6 to 17 April 2020, all candidates for chemotherapy, radiotherapy or target/immunotherapy, if negative at the standard clinical triage on the day scheduled for anticancer treatment, received a rapid serological test on peripheral blood for COVID-19 IgM and IgG detection. In case of COVID-19 IgM and/or IgG positivity, patients underwent a real-time PCR (RT-PCR) SARS-CoV-2 test to confirm infection, and active cancer treatment was delayed.ResultsOverall 466 patients, negative for COVID-19 symptoms, underwent serological testing in addition to standard clinical triage. The average age was 61 years (range 25–88 years). Most patients (190, 40.8%) had breast cancer, and chemotherapy with or without immunotherapy was administered in 323 (69.3%) patients. Overall 433 (92.9%) patients were IgG-negative and IgM-negative, and 33 (7.1%) were IgM-positive and/or IgG-positive. Among the latter patients, 18 (3.9%), 11 (2.4%) and 4 (0.9%) were IgM-negative/IgG-positive, IgM-positive/IgG-negative and IgM-positive/IgG-positive, respectively. All 33 patients with a positive serological test, tested negative for RT-PCR SARS-CoV-2 test. No patient in our cohort developed symptoms suggestive of active COVID-19 infection.ConclusionRapid serological testing at hospital admission failed to detect active asymptomatic COVID-19 infection. Moreover, it entailed additional economic and human resources, delayed therapy administrationand increased hospital accesses.

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