Immune Correlates Analysis of the mRNA-1273 COVID-19 Vaccine Efficacy Trial

Background: In the Coronavirus Efficacy (COVE) trial, estimated mRNA-1273 vaccine efficacy against coronavirus disease-19 (COVID-19) was 94%. SARS-CoV-2 antibody measurements were assessed as correlates of COVID-19 risk and as correlates of protection. Methods: Through case-cohort sampling, participants were selected for measurement of four serum antibody markers at Day 1 (first dose), Day 29 (second dose), and Day 57: IgG binding antibodies (bAbs) to Spike, bAbs to Spike receptor-binding domain (RBD), and 50% and 80% inhibitory dilution pseudovirus neutralizing antibody titers calibrated to the WHO International Standard (cID50 and cID80). Participants with no evidence of previous SARS-CoV-2 infection were included. Cox regression assessed in vaccine recipients the association of each Day 29 or 57 serologic marker with COVID-19 through 126 or 100 days of follow-up, respectively, adjusting for risk factors. Results: Day 57 Spike IgG, RBD IgG, cID50, and cID80 neutralization levels were each inversely correlated with risk of COVID-19: hazard ratios 0.66 (95% CI 0.50, 0.88; p=0.005); 0.57 (0.40, 0.82; p=0.002); 0.41 (0.26, 0.65; p<0.001); 0.35 (0.20, 0.60; p<0.001) per 10-fold increase in marker level, respectively, multiplicity adjusted P-values 0.003-0.010. Results were similar for Day 29 markers (multiplicity adjusted P-values <0.001-0.003). For vaccine recipients with Day 57 reciprocal cID50 neutralization titers that were undetectable (<2.42), 100, or 1000, respectively, cumulative incidence of COVID-19 through 100 days post Day 57 was 0.030 (0.010, 0.093), 0.0056 (0.0039, 0.0080), and 0.0023 (0.0013, 0.0036). For vaccine recipients at these titer levels, respectively, vaccine efficacy was 50.8% (-51.2, 83.0%), 90.7% (86.7, 93.6%), and 96.1% (94.0, 97.8%). Causal mediation analysis estimated that the proportion of vaccine efficacy mediated through Day 29 cID50 titer was 68.5% (58.5, 78.4%). Conclusions: Binding and neutralizing antibodies correlated with COVID-19 risk and vaccine efficacy and likely have utility in predicting mRNA-1273 vaccine efficacy against COVID-19. Trial registration number: COVE ClinicalTrials.gov number, NCT04470427

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A longitudinal study of SARS-CoV-2-infected patients reveals a high correlation between neutralizing antibodies and COVID-19 severity

Cellular and Molecular Immunology ◽

10.1038/s41423-020-00588-2 ◽

2021 ◽

Author(s):

Vincent Legros ◽

Solène Denolly ◽

Manon Vogrig ◽

Bertrand Boson ◽

Eglantine Siret ◽

...

Keyword(s):

Intensive Care ◽

Neutralizing Antibodies ◽

Vaccine Development ◽

Surface Protein ◽

Humoral Response ◽

Neutralizing Antibody ◽

Rapid Decline ◽

Serum Samples ◽

Immune Correlates ◽

Human Coronaviruses

AbstractUnderstanding the immune responses elicited by SARS-CoV-2 infection is critical in terms of protection against reinfection and, thus, for public health policy and vaccine development for COVID-19. In this study, using either live SARS-CoV-2 particles or retroviruses pseudotyped with the SARS-CoV-2 S viral surface protein (Spike), we studied the neutralizing antibody (nAb) response in serum samples from a cohort of 140 SARS-CoV-2 qPCR-confirmed infections, including patients with mild symptoms and also more severe forms, including those that required intensive care. We show that nAb titers correlated strongly with disease severity and with anti-spike IgG levels. Indeed, patients from intensive care units exhibited high nAb titers; conversely, patients with milder disease symptoms had heterogeneous nAb titers, and asymptomatic or exclusive outpatient-care patients had no or low nAbs. We found that nAb activity in SARS-CoV-2-infected patients displayed a relatively rapid decline after recovery compared to individuals infected with other coronaviruses. Moreover, we found an absence of cross-neutralization between endemic coronaviruses and SARS-CoV-2, indicating that previous infection by human coronaviruses may not generate protective nAbs against SARS-CoV-2. Finally, we found that the D614G mutation in the spike protein, which has recently been identified as the current major variant in Europe, does not allow neutralization escape. Altogether, our results contribute to our understanding of the immune correlates of SARS-CoV-2-induced disease, and rapid evaluation of the role of the humoral response in the pathogenesis of SARS-CoV-2 is warranted.

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Long-term persistence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein-specific and neutralizing antibodies in recovered COVID-19 patients

10.21203/rs.3.rs-1073046/v1 ◽

2021 ◽

Author(s):

Jira Chansaenroj ◽

Ritthideach Yorsaeng ◽

Nasamon Wanlapakorn ◽

Chintana Chirathaworn ◽

Natthinee Sudhinaraset ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Symptom Onset ◽

Neutralizing Antibodies ◽

Serum Antibody ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Spike Protein ◽

Immunological Study ◽

Igg Antibody ◽

Vaccine Schedule

Abstract Understanding antibody responses after natural severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can guide the coronavirus disease 2019 (COVID-19) vaccine schedule. This study aimed to assess the dynamics of SARS-CoV-2 antibodies, including anti-spike protein 1 (S1) immunoglobulin (Ig)G, anti-receptor-binding domain (RBD) total Ig, anti-S1 IgA, and neutralizing antibody against wild-type SARS-CoV-2 in a cohort of patients who were previously infected with SARS-CoV-2. Between March and May 2020, 531 individuals with virologically confirmed cases of SARS-CoV-2 infection were enrolled in our immunological study. The neutralizing titers against SARS-CoV-2 were detected in 95.2%, 86.7%, 85.0%, and 85.4% of recovered COVID-19 patients at 3, 6, 9, and 12 months after symptom onset, respectively. The seropositivity rate of anti-S1 IgG, anti-RBD total Ig, anti-S1 IgA, and neutralizing titers remained at 68.6%, 89.6%, 77.1%, and 85.4%, respectively, at 12 months after symptom onset. The half-life of neutralizing titers was estimated at 100.7 days (95% confidence interval = 44.5 – 327.4 days, R2 = 0.106). These results support that the decline in serum antibody levels over time depends on the symptom severity, and the individuals with high IgG antibody titers experienced a significantly longer persistence of SARS-CoV-2-specific antibody responses than those with lower titers.

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Potent anti-SARS-CoV-2 Antibody Responses are Associated with Better Prognosis in Hospital Inpatient COVID-19 Disease

10.1101/2020.08.22.20176834 ◽

2020 ◽

Author(s):

Patrick J Tighe ◽

Richard A Urbanowicz ◽

Lucy Fairclough ◽

C Patrick McClure ◽

Brian J Thomson ◽

...

Keyword(s):

Antibody Response ◽

Neutralizing Antibodies ◽

Clinical Intervention ◽

Neutralizing Antibody ◽

Antibody Responses ◽

Spike Protein ◽

Effective Vaccine ◽

Hospital Inpatient ◽

Protein Variant ◽

Immune Correlates

COVID-19 continues to cause a pandemic, having infected more than 20 million people globally. Successful elimination of the SARS-CoV-2 virus will require an effective vaccine. However, the immune correlates of infection are currently poorly understood. While neutralizing antibodies are believed to be essential for protection against infection, the contribution of the neutralizing antibody response to resolution of SARS-CoV-2 infection has not yet been defined. In this study the antibody responses to the SARS-CoV-2 spike protein and nucleocapsid proteins were investigated in a UK patient cohort, using optimised immunoassays and a retrovirus-based pseudotype entry assay. It was discovered that in severe COVID-19 infections an early antibody response to both antigens was associated with improved prognosis of infection. While not all SARS-CoV-2-reactive sera were found to possess neutralizing antibodies, neutralizing potency of sera was found to be greater in patients who went on to resolve infection, compared with those that died from COVID-19. Furthermore, viral genetic variation in spike protein was found to influence the production of neutralizing antibodies. Infection with the recently described spike protein variant 614G produced higher levels of neutralizing antibodies when compared to viruses possessing the 614D variant. These findings support the assertion that vaccines targeting generation of neutralizing antibodies may be useful at limiting SARS-CoV-2 infection. Assessment of the antibody responses to SARS-CoV-2 at time of diagnosis will be a useful addition to the diagnostic toolkit, enabling stratification of clinical intervention for severe COVID-19 disease.

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Glycosylation of Immunodominant Linear Epitopes in the Carboxy-Terminal Region of the Caprine Arthritis-Encephalitis Virus Surface Envelope Enhances Vaccine-Induced Type-Specific and Cross-Reactive Neutralizing Antibody Responses

Journal of Virology ◽

10.1128/jvi.78.17.9190-9202.2004 ◽

2004 ◽

Vol 78 (17) ◽

pp. 9190-9202 ◽

Cited By ~ 7

Author(s):

J. D. Trujillo ◽

N. M. Kumpula-McWhirter ◽

K. J. Hötzel ◽

M. Gonzalez ◽

W. P. Cheevers

Keyword(s):

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Fold Increase ◽

Antibody Responses ◽

Enzyme Linked Immunosorbent Assay ◽

Wild Type ◽

Virus Surface ◽

Antibody Titers ◽

Linear Epitopes ◽

Carboxy Terminal

ABSTRACT This study evaluated type-specific and cross-reactive neutralizing antibodies induced by immunization with modified surface glycoproteins (SU) of the 63 isolate of caprine arthritis-encephalitis lentivirus (CAEV-63). Epitope mapping of sera from CAEV-infected goats localized immunodominant linear epitopes in the carboxy terminus of SU. Two modified SU (SU-M and SU-T) and wild-type CAEV-63 SU (SU-W) were produced in vaccinia virus and utilized to evaluate the effects of glycosylation or the deletion of immunodominant linear epitopes on neutralizing antibody responses induced by immunization. SU-M contained two N-linked glycosylation sites inserted into the target epitopes by R539S and E542N mutations. SU-T was truncated at 518A, upstream from the target epitopes, by introduction of termination codons at 519Y and 521Y. Six yearling Saanen goats were immunized subcutaneously with 30 μg of SU-W, SU-M, or SU-T in Quil A adjuvant and boosted at 3, 7, and 16 weeks. SU antibody titers determined by indirect enzyme-linked immunosorbent assay demonstrated anamnestic responses after each boost. Wild-type and modified SU-induced type-specific CAEV-63 neutralizing antibodies and cross-reactive neutralizing antibodies against CAEV-Co, a virus isolate closely related to CAEV-63, and CAEV-1g5, an isolate geographically distinct from CAEV-63, were determined. Immunization with SU-T resulted in altered recognition of SU linear epitopes and a 2.8- to 4.6-fold decrease in neutralizing antibody titers against CAEV-63, CAEV-Co, and CAEV-1g5 compared to titers of SU-W-immunized goats. In contrast, immunization with SU-M resulted in reduced recognition of glycosylated epitopes and a 2.4- to 2.7-fold increase in neutralizing antibody titers compared to titers of SU-W-immunized goats. Thus, the glycosylation of linear immunodominant nonneutralization epitopes, but not epitope deletion, is an effective strategy to enhance neutralizing antibody responses by immunization.

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Shedding of infectious SARS-CoV-2 by hospitalized COVID-19 patients in relation to serum antibody responses

BMC Infectious Diseases ◽

10.1186/s12879-021-06202-8 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Hedvig Glans ◽

Sara Gredmark-Russ ◽

Mikaela Olausson ◽

Sara Falck-Jones ◽

Renata Varnaite ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Serum Antibody ◽

Neutralizing Antibody ◽

University Hospital ◽

Pcr Analysis ◽

Symptom Duration ◽

Cross Sectional ◽

Antibody Titers ◽

Specific Igg

Abstract Background Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a global pandemic. The understanding of the transmission and the duration of viral shedding in SARS-CoV-2 infection is still limited. Objectives To assess the timeframe and potential risk of SARS-CoV-2 transmission from hospitalized COVID-19 patients in relation to antibody response. Method We performed a cross-sectional study of 36 COVID-19 patients hospitalized at Karolinska University Hospital. Patients with more than 8 days of symptom duration were sampled from airways, for PCR analysis of SARS-CoV-2 RNA and in vitro culture of replicating virus. Serum SARS-CoV-2-specific immunoglobulin G (IgG) and neutralizing antibodies titers were assessed by immunofluorescence assay (IFA) and microneutralization assay. Results SARS-CoV-2 RNA was detected in airway samples in 23 patients (symptom duration median 15 days, range 9–53 days), whereas 13 patients were SARS-CoV-2 RNA negative (symptom duration median 21 days, range 10–37 days). Replicating virus was detected in samples from 4 patients at 9–16 days. All but two patients had detectable levels of SARS-CoV-2-specific IgG in serum, and SARS-CoV-2 neutralizing antibodies were detected in 33 out of 36 patients. Total SARS-CoV-2-specific IgG titers and neutralizing antibody titers were positively correlated. High levels of both total IgG and neutralizing antibody titers were observed in patients sampled later after symptom onset and in patients where replicating virus could not be detected. Conclusions Our data suggest that the presence of SARS-Cov-2 specific antibodies in serum may indicate a lower risk of shedding infectious SARS-CoV-2 by hospitalized COVID-19 patients.

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Exponential increase in neutralizing and spike specific antibodies following vaccination of COVID-19 convalescent plasma donors

10.1101/2021.02.02.21250836 ◽

2021 ◽

Author(s):

Molly A. Vickers ◽

Alan Sariol ◽

Judith Leon ◽

Alexandra Ehlers ◽

Aaron V. Locher ◽

...

Keyword(s):

Specific Antibody ◽

Neutralizing Antibodies ◽

Case Series ◽

Neutralizing Antibody ◽

Fold Increase ◽

Chemiluminescence Immunoassay ◽

Specific Antibodies ◽

Exponential Increase ◽

Single Vaccination ◽

Antibody Levels

AbstractBackgroundWith the recent approval of COVID-19 vaccines, recovered COVID-19 subjects who are vaccinated may be ideal candidates to donate COVID-19 convalescent plasma (CCP).Case SeriesThree recovered COVID-19 patients were screened to donate CCP. All had molecularly confirmed COVID-19, and all were antibody positive by chemiluminescence immunoassay (DiaSorin) prior to vaccination. All were tested again for antibodies 11 to 21 days after they received the first dose of the vaccine (Pfizer). All showed dramatic increases (∼50 fold) in spike-specific antibody levels and had at least a 20-fold increase in the IC50 neutralizing antibody titer based on plaque reduction neutralization testing (PRNT). The spike-specific antibody levels following vaccination were significantly higher than those seen in any non-vaccinated COVID-19 subjects tested to date at our facility.ConclusionSpike-specific and neutralizing antibodies demonstrated dramatic increases following a single vaccination post COVID-19 infection which significantly exceeded values seen with COVID-19 infection alone. Recovered COVID-19 subjects who are vaccinated may make ideal candidates for CCP donation.

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Immunogenicity of heterologous BNT162b2 booster in fully vaccinated individuals with CoronaVac against SARS-CoV-2 variants Delta and Omicron: the Dominican Republic Experience

10.1101/2021.12.27.21268459 ◽

2021 ◽

Author(s):

Eddy Perez-Then ◽

Carolina Lucas ◽

Valter Silva Monteiro ◽

Marija Miric ◽

Vivian Brache ◽

...

Keyword(s):

Dominican Republic ◽

Dose Regimen ◽

Neutralizing Antibodies ◽

Immune Escape ◽

Neutralizing Antibody ◽

Fold Increase ◽

Neutralization Activity ◽

Recent Emergence ◽

Virus Specific Antibody ◽

The Impact

The recent emergence of the SARS-CoV-2 Omicron variant is raising concerns because of its increased transmissibility and by its numerous spike mutations with potential to evade neutralizing antibodies elicited by COVID-19 vaccines. The Dominican Republic was among the first countries in recommending the administration of a third dose COVID-19 vaccine to address potential waning immunity and reduced effectiveness against variants. Here, we evaluated the effects of a heterologous BNT162b2 mRNA vaccine booster on the humoral immunity of participants that had received a two-dose regimen of CoronaVac, an inactivated vaccine used globally. We found that heterologous CoronaVac prime followed by BNT162b2 booster regimen induces elevated virus-specific antibody levels and potent neutralization activity against the ancestral virus and Delta variant, resembling the titers obtained after two doses of mRNA vaccines. While neutralization of Omicron was undetectable in participants that had received a two-dose regimen of CoronaVac vaccine, BNT162b2 booster resulted in a 1.4-fold increase in neutralization activity against Omicron, compared to two-dose mRNA vaccine. Despite this increase, neutralizing antibody titers were reduced by 6.3-fold and 2.7-fold for Omicron compared to ancestral and Delta variant, respectively. Surprisingly, previous SARS-CoV-2 infection did not affect the neutralizing titers for Omicron in participants that received the heterologous regimen. Our findings have immediate implications for multiples countries that previously used a two-dose regimen of CoronaVac and reinforce the notion that the Omicron variant is associated with immune escape from vaccines or infection-induced immunity, highlighting the global need for vaccine boosters to combat the impact of emerging variants.

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Glycan-masking spike antigen in NTD and RBD elicits broadly neutralizing antibodies against SARS-CoV-2 variants

10.1101/2021.11.01.466834 ◽

2021 ◽

Author(s):

Wei-Shuo Lin ◽

I-Chen Chen ◽

Hui-Chen Chen ◽

Yi-Chien Lee ◽

Suh-Chin Wu

Keyword(s):

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Fold Increase ◽

Vaccine Antigen ◽

Broadly Neutralizing Antibodies ◽

Neutralization Titer ◽

Cell Responses ◽

Folded Structure ◽

Antibody Titers ◽

The Impact

Glycan-masking the vaccine antigen by mutating the undesired antigenic sites with an additional N-linked glycosylation motif can refocus B-cell responses to desired/undesired epitopes, without affecting the antigen overall-folded structure. This study examine the impact of glycan-masking mutants of the N-terminal domain (NTD) and receptor-binding domain (RBD) of SARS-CoV-2, and found that the antigenic design of the S protein increases the neutralizing antibody titers against the Wuhan-Hu-1 ancestral strain and the recently emerged SARS-CoV-2 variants Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2). Our results demonstrated that the use of glycan-masking Ad-S-R158N-Y160T in the NTD elicited a 2.8-fold, 6.5-fold, and 4.6-fold increase in the IC-50 NT titer against the Alpha (B.1.1.7), Beta (B.1.351) and Delta (B.1.617.2) variants, respectively. Glycan-masking of Ad-S-D428N in the RBD resulted in a 3.0-fold and 2.0-fold increase in the IC50 neutralization titer against the Alpha (B.1.1.7) and Beta (B.1.351) variants, respectively. The use of glycan-masking in Ad-S-R158N-Y160T and Ad-S-D428N antigen design may help develop universal COVID-19 vaccines against current and future emerging SARS-CoV-2 variants.

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Predicting COVID-19 Vaccine Efficacy from Neutralizing Antibody Levels

10.1101/2021.10.13.21264921 ◽

2021 ◽

Author(s):

Majid R. Abedi ◽

Samuel Dixon ◽

Timothy Guyon ◽

Serene Hsu ◽

Aviva R. Jacobs ◽

...

Keyword(s):

High Throughput ◽

Vaccine Efficacy ◽

Neutralizing Antibodies ◽

Neutralization Test ◽

Neutralizing Antibody ◽

Published Data ◽

Real World Data ◽

Symptomatic Infection ◽

Viral Neutralization ◽

Antibody Levels

Recent studies using data accrued from global SARS-CoV-2 vaccination efforts have demonstrated that breakthrough infections are correlated with levels of neutralizing antibodies. The decrease in neutralizing antibody titers of vaccinated individuals over time, combined with the emergence of more infectious variants of concern has resulted in waning vaccine efficacy against infection and a rise in breakthrough infections. Here we use a combination of neutralizing antibody measurements determined by a high throughput surrogate viral neutralization test (sVNT) together with published data from vaccine clinical trials and comparative plaque reduction neutralization test (PRNT) between SARS-CoV-2 variants to develop a model for vaccine efficacy (VE) against symptomatic infection. Vaccine efficacy estimates using this model show good concordance with real world data from the US and Israel. Our work demonstrates that appropriately calibrated neutralizing antibody measurements determined by high throughput sVNT can be used to provide a semi-quantitative estimate of protection against infection. Given the highly variable antibody levels among the vaccinated population, this model may be of use in identification of individuals with an elevated risk of breakthrough infections.

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QUANTITATIVE STUDIES OF THE VIRUS-HOST RELATIONSHIP IN CHIMPANZEES AFTER INAPPARENT INFECTION WITH COXSACKIE VIRUSES

Journal of Experimental Medicine ◽

10.1084/jem.97.3.367 ◽

1953 ◽

Vol 97 (3) ◽

pp. 367-400 ◽

Cited By ~ 14

Author(s):

Joseph L. Melnick ◽

Albert S. Kaplan

Keyword(s):

Neutralizing Antibodies ◽

Neutralizing Antibody ◽

Fold Increase ◽

Carrier State ◽

Virus Multiplication ◽

Rapid Decline ◽

Challenge Virus ◽

Short Period ◽

Set Up ◽

Antigenic Type

Following oral administration of Coxsackie viruses (C viruses) to susceptible chimpanzees, these agents can be isolated from the throat for a period of approximately a week, from the blood for a few days, and from the stools for 2 to 3 weeks or even longer. Animals so infected respond with the formation of specific neutralizing antibodies which are maintained for at least 1 to 2 years. Such chimpanzees are immune when challenged orally with homologous strains of virus. They then excrete virus in the stools for 3 or 4 days (passive transfer); no virus can be recovered from the throats and blood of these animals, and neutralizing antibody levels remain unchanged. Animals immune to one antigenic type of C virus can be infected by feeding a different antigenic type. Following such a heterotypic challenge, virus can again be isolated from the throat, blood, and stools; neutralizing antibodies develop to the new strain. Antibodies to the Texas-1 type of C virus were already present in four chimpanzees upon their arrival in the laboratory from Africa. It was possible to set up intestinal carriage of the Texas-1 virus in these animals and to demonstrate a 10- to 100-fold increase in titer of neutralizing, as well as complement-fixing, antibody. Quantitative titrations of the amount of virus present in the stools and throat were performed. Immediately after the first feeding of virus relatively large amounts can be detected in the stools; the titer drops, but may be maintained for as long as 25 days at 10–2 to 10–3, furnishing evidence that virus multiplication has taken place. Virus in the throat reached the same order of magnitude at first as in the stools but there was a rapid decline to zero in a few days. The Ohio-1 virus differed from the others in that it persisted in the throat as long as in the stools, and in several instances reached a higher titer in the throat. Following homotypic challenge with all types, virus could be detected in the stools for only a relatively short period of time and at low concentration. Virus-neutralizing substances could not be detected in the stools or throat swabs of convalescent animals, at a time when their serum-neutralizing antibody titers were high. Under the limited conditions of the present experiments, C viruses had no effect on the infection of chimpanzees with three different antigenic types of poliomyelitis virus. Both poliomyelitis and C viruses set up independent infections without apparent interaction between them. No enhancement of the poliomyelitis infection took place, as was plain from the fact that none of the infected chimpanzees became paralyzed. a titration of Texas-1 C virus in four chimpanzees revealed that a suspension of infected tissue diluted to 106.0 could cause the development of the carrier state; accidental infection of control animals with other Coxsackie types indicated also that very little virus may be necessary to initiate infection. Seven distinct antigenic types of C virus were inoculated subcutaneously and intramuscularly at the same time into four chimpanzees. The response was the same as that following feeding; virus could be recovered from the throat, blood, and stools, and the animals developed neutralizing antibodies to all seven types of C virus. There was no detectable interference among the viruses. Cortisone did not bring about the reappearance of the virus excretion in chimpanzees previously infected and shown to be intestinal carriers of poliomyelitis and Coxsackie viruses.

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