Effect of BCG Revaccination on Occupationally Exposed Medical Personnel Vaccinated against SARS-CoV-2

The production of specific neutralizing antibodies by individuals is thought to be the best option for reducing the number of patients with severe COVID-19, which is the reason why multiple vaccines are currently being administered worldwide. We aimed to explore the effect of revaccination with BCG, on the response to a subsequent anti-SARS-CoV-2 vaccine, in persons occupationally exposed to COVID-19 patients. Two groups of 30 randomized participants were selected: one group received a BCG revaccination, and the other group received a placebo. Subsequently, both groups were vaccinated against SARS-CoV-2. After each round of vaccination, the serum concentration of Th1/Th2 cytokines was determined. At the end of the protocol, neutralizing antibodies were determined and the HLA-DRB loci were genotyped. The participants from the BCG group and anti-SARS-CoV-2 vaccine group had increased serum cytokine concentrations (i.e., IL-1β, IL-4, IL-6, IL-12p70, IL-13, IL-18, GM-CSF, INF-γ, and TNF-α) and higher neutralizing antibody titers, compared to the group with Placebo–anti-SARS-CoV-2. Twelve HLA-DRB1 alleles were identified in the Placebo–anti-SARS-CoV-2 group, and only nine in the group revaccinated with BCG. The DRB1*04 allele exhibited increased frequency in the Placebo–anti-SARS-CoV-2 group; however, no confounding effects were found with this allele. We conclude that revaccination with BCG synergizes with subsequent vaccination against SARS-CoV-2 in occupationally exposed personnel.

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Titers of Neutralizing Antibodies against SARS-CoV-2 Are Independent of Symptoms of Non-Severe COVID-19 in Young Adults

Viruses ◽

10.3390/v13020284 ◽

2021 ◽

Vol 13 (2) ◽

pp. 284

Author(s):

Hulda R. Jonsdottir ◽

Michel Bielecki ◽

Denise Siegrist ◽

Thomas W. Buehrer ◽

Roland Züst ◽

...

Keyword(s):

Young Adults ◽

Neutralizing Antibodies ◽

Severe Disease ◽

Humoral Response ◽

Neutralizing Antibody ◽

Neutralization Assay ◽

Asymptomatic Infection ◽

Homogeneous Population ◽

Humoral Immune ◽

Antibody Titers

Neutralizing antibodies are an important part of the humoral immune response to SARS-CoV-2. It is currently unclear to what extent such antibodies are produced after non-severe disease or asymptomatic infection. We studied a cluster of SARS-CoV-2 infections among a homogeneous population of 332 predominantly male Swiss soldiers and determined the neutralizing antibody response with a serum neutralization assay using a recombinant SARS-CoV-2-GFP. All patients with non-severe COVID-19 showed a swift humoral response within two weeks after the onset of symptoms, which remained stable for the duration of the study. One month after the outbreak, titers in COVID-19 convalescents did not differ from the titers of asymptomatically infected individuals. Furthermore, symptoms of COVID-19 did not correlate with neutralizing antibody titers. Therefore, we conclude that asymptomatic infection can induce the same humoral immunity as non-severe COVID-19 in young adults.

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Durability of Response to a Third BNT162b2 Vaccine in Adults ≥60 Years

10.1101/2021.12.25.21268336 ◽

2021 ◽

Author(s):

Noa Eliakim Raz ◽

Amos Stemmer ◽

Yaara Leibovici-Weissman ◽

Asaf Ness ◽

Muhammad Awwad ◽

...

Keyword(s):

Adverse Events ◽

Neutralizing Antibodies ◽

Multivariable Analysis ◽

Vaccine Dose ◽

Neutralizing Antibody ◽

Clinical Frailty Scale ◽

Younger Adults ◽

The Third ◽

Antibody Titers ◽

Level 2

BACKGROUND Age and frailty are strong predictors of COVID-19 mortality. After the second BNT162b2 dose, immunity wanes faster in older (≥65 years) versus younger adults. The durability of response after the third vaccine is unclear. METHODS This prospective cohort study included healthcare workers/family members ≥60 years who received a third BNT162b2 dose. Blood samples were drawn immediately before (T0), 10-19 (T1), and 74-103 (T2) days after the third dose. Antispike IgG titers were determined using a commercial assay, seropositivity was defined as ≥50 AU/mL. Neutralizing antibody titers were determined at T2. Adverse events, COVID-19 infections, and clinical frailty scale (CFS) levels were documented. RESULTS The analysis included 97 participants (median age, 70 years [IQR, 66-74], 61% women, 58% CFS level 2). IgG titers, which increased significantly from T0 to T1 (medians, 440 AU/mL [IQR, 294-923] and 25,429 [14,203-36,114] AU/mL, respectively; P<0.001), decreased significantly by T2, but all remained seropositive (median, 8,306 AU/mL [IQR, 4595-14,701], P<0.001 vs T1). In a multivariable analysis, only time from the first vaccine was significantly associated with lower IgG levels at T2 (P=0.004). At T2, 60 patients were evaluated for neutralizing antibodies; all were seropositive (median, 1,294 antibody titer [IQR, 848-2,072]). Neutralizing antibody and antispike IgG levels were correlated (R=0.6, P<0.001). No major adverse events or COVID-19 infections were reported. CONCLUSIONS Antispike IgG and neutralizing antibodies levels remain adequate 3 months after the third BNT162b2 vaccine in healthy adults ≥60 years, although the decline in IgG is concerning. A third vaccine dose in this population should be top priority.

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Antibody titers measured by commercial assays are correlated with neutralizing antibody titers calibrated by international standards

10.1101/2021.07.16.21260618 ◽

2021 ◽

Author(s):

Yu-An Kung ◽

Chung-Guei Huang ◽

Sheng-Yu Huang ◽

Kuan-Ting Liu ◽

Peng-Nien Huang ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Geometric Mean ◽

Neutralizing Antibody ◽

Diagnostic Techniques ◽

International Standards ◽

World Health ◽

Serum Samples ◽

Antibody Titers ◽

Health Organization

The World Health Organization (WHO) has highlighted the importance of an international standard (IS) for SARS-CoV-2 neutralizing antibody titer detection, with the aim of calibrating different diagnostic techniques. In this study, IS was applied to calibrate neutralizing antibody titers (IU/mL) and binding antibody titers (BAU/mL) in response to SARS-CoV-2 vaccines. Serum samples were collected from participants receiving the Moderna (n = 20) and Pfizer (n = 20) vaccines at three time points: pre-vaccination, after one dose, and after two doses. We obtained geometric mean titers of 1404.16 and 928.75 IU/mL for neutralizing antibodies after two doses of the Moderna and Pfizer vaccines, respectively. These values provide an important baseline for vaccine development and the implementation of non-inferiority trials. We also compared three commercially available kits from Roche, Abbott, and MeDiPro for the detection of COVID-19 antibodies based on binding affinity to S1 and/or RBD. Our results demonstrated that antibody titers measured by commercial assays are highly correlated with neutralizing antibody titers calibrated by IS.

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Distinct cellular immune signatures in acute Zika virus infection are associated with high or low persisting neutralizing antibody titers

10.1101/2021.05.27.446054 ◽

2021 ◽

Author(s):

Elizabeth E. McCarthy ◽

Pamela M. Odorizzi ◽

Emma Lutz ◽

Carolyn P. Smullin ◽

Iliana Tenvooren ◽

...

Keyword(s):

Zika Virus ◽

Neutralizing Antibodies ◽

Viral Infections ◽

Immune Cell ◽

Acute Infection ◽

Neutralizing Antibody ◽

Natural Immunity ◽

Zikv Infection ◽

Antibody Titers ◽

Cellular Immune

Although the formation of a durable neutralizing antibody response after an acute viral infection is a key component of protective immunity, little is known about why some individuals generate high versus low neutralizing antibody titers to infection or vaccination. Infection with Zika virus (ZIKV) during pregnancy can cause devastating fetal outcomes, and efforts to understand natural immunity to this infection are essential for optimizing vaccine design. In this study, we leveraged the high-dimensional single-cell profiling capacity of mass cytometry (CyTOF) to deeply characterize the cellular immune response to acute and convalescent ZIKV infection in a cohort of blood donors in Puerto Rico incidentally found to be viremic during the 2015-2016 epidemic in the Americas. During acute ZIKV infection, we identified widely coordinated responses across innate and adaptive immune cell lineages. High frequencies of multiple activated innate immune subsets, as well as activated follicular helper CD4+ T cells and proliferating CD27-IgD- B cells, during acute infection were associated with high titers of ZIKV neutralizing antibodies at 6 months post-infection. On the other hand, low titers of ZIKV neutralizing antibodies were associated with immune features that suggested a cytotoxic-skewed immune "set-point." Our study offers insight into the cellular coordination of immune responses and identifies candidate cellular biomarkers that may offer predictive value in vaccine efficacy trials for ZIKV and other acute viral infections aimed at inducing high titers of neutralizing antibodies.

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Safety and Immunogenicity Evaluation of Inactivated whole-virus-SARS-COV-2 As Emerging Vaccine Development In Egypt

10.1101/2021.03.01.433130 ◽

2021 ◽

Author(s):

Amani A. Saleh ◽

Mohamed A. Saad ◽

Islam Ryan ◽

Magdy Amin ◽

Mohamed I. Shindy ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Clinical Symptoms ◽

Neutralizing Antibody ◽

Positive Development ◽

Virus Challenge ◽

Cell Monolayers ◽

Transmission Electron ◽

Dose Concentration ◽

Antibody Titers

AbstractThe current worldwide pandemic COVID-19 is causing severe human health problems, with high numbers of mortality rates and huge economic burdens that require an urgent demand for safe, and effective and vaccine development. Our study was the first trail to development and evaluation of safety and immune response to inactivated whole SARS-COV-2 virus vaccine adjuvanted with aluminium hydroxide. We used characterized SARS-COV-2 strain, severe acute respiratory syndrome coronavirus 2 isolates (SARS-CoV-2/human/EGY/Egy-SERVAC/2020) with accession numbers; MT981440; MT981439; MT981441; MT974071; MT974069 and MW250352 at GenBank that isolated from Egyptian patients SARS-CoV-2-positive. Development of the vaccine was carried out in a BSL - 3 facilities and the immunogenicity was determined in mice at two doses (55µg and 100µg per dose). All vaccinated mice were received a booster dose 14 days post first immunization. Our results demonstrated distinct cytopathic effect on the vero cell monolayers induced through SARS-COV-2 propagation and the viral particles were identified as Coronaviridae by transmission electron microscopy. SARS-CoV-2 was identified by RT-PCR performed on the cell culture. Immunogenicity of the developed vaccine indicated the high antigen-binding and neutralizing antibody titers, regardless the dose concentration, with excellent safety profiles.However, no deaths or clinical symptoms in mice groups. The efficacy of the inactivated vaccine formulation was tested by wild virus challenge the vaccinated mice and detection of viral replication in lung tissues. Vaccinated mice recorded complete protection from challenge infection three weeks post second dose. SARS-COV-2 replication was not observed in the lungs of mice following SARS-CoV-2 challenge, regardless of the level of serum neutralizing antibodies. This finding will support the future trials for evaluation an applicable SARS-CoV-2 vaccine candidate.

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Anti-HMGB1 Neutralizing Antibody Attenuates Periodontal Inflammation and Bone Resorption in a Murine Periodontitis Model

Infection and Immunity ◽

10.1128/iai.00111-18 ◽

2018 ◽

Vol 86 (5) ◽

Cited By ~ 16

Author(s):

Chiaki Yoshihara-Hirata ◽

Keisuke Yamashiro ◽

Tadashi Yamamoto ◽

Hiroaki Aoyagi ◽

Hidetaka Ideguchi ◽

...

Keyword(s):

Bone Resorption ◽

Neutralizing Antibody ◽

Myeloperoxidase Activity ◽

Micro Computed Tomography ◽

Gm Csf ◽

Periodontal Inflammation ◽

Periodontal Infection ◽

Tnf Α ◽

Inflammatory Stimuli

ABSTRACTHigh mobility group box 1 (HMGB1) is a non-histone DNA-binding protein that is secreted into the extracellular milieu in response to inflammatory stimuli. The secreted HMGB1 mediates various inflammatory diseases, including periodontitis; however, the underlying mechanisms of HMGB1-induced periodontal inflammation are not completely understood. Here, we examined whether anti-HMGB1 neutralizing antibody inhibits periodontal progression and investigated the molecular pathology of HMGB1in vitroandin vivo. In vitroanalysis indicated that HMGB1, granulocyte-macrophage colony-stimulating factor (GM-CSF), and interleukin-1β (IL-1β) were secreted in response to tumor necrosis factor-α (TNF-α) stimuli in human gingival epithelial cells (HGECs) and human monocytic leukemia cells (THP-1) treated with phorbol myristate acetate. Increased levels of GM-CSF and IL-1β were observed in the conditioned media from TNF-α-stimulated HGECs and THP-1in vitro. Simultaneous stimulation with TNF-α and anti-HMGB1 antibody significantly decreased TNF-α-induced inflammatory cytokine secretion. Experimental periodontitis was induced in mice usingPorphyromonas gingivalis-soaked ligatures. The extracellular translocation was confirmed in gingival epithelia in the periodontitis model mice by immunofluorescence analysis. Systemic administration of anti-HMGB1 neutralizing antibody significantly inhibited translocation of HMGB1. The anti-HMGB1 antibody inhibited periodontal inflammation, expression of IL-1β and C-X-C motif chemokine ligand 1 (CXCL1), migration of neutrophils, and bone resorption, shown by bioluminescence imaging of myeloperoxidase activity, quantitative reverse transcription-PCR (RT-PCR), and micro-computed tomography analysis. These findings indicate that HMGB1 is secreted in response to inflammatory stimuli caused by periodontal infection, which is crucial for the initiation of periodontitis, and the anti-HMGB1 antibody attenuates the secretion of a series of inflammatory cytokines, consequently suppressing the progression of periodontitis.

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Prevalence and Persistence of Maternal Dengue Neutralizing Antibodies in Infants From Central and Southern Thailand: A Retrospective Cohort Study

Asia Pacific Journal of Public Health ◽

10.1177/1010539519853396 ◽

2019 ◽

Vol 31 (4) ◽

pp. 288-295 ◽

Cited By ~ 1

Author(s):

Adrienne Guignard ◽

François Haguinet ◽

Stéphanie Wéry ◽

Phirangkul Kerdpanich

Keyword(s):

Neutralizing Antibodies ◽

Vaccine Development ◽

Geometric Mean ◽

Neutralizing Antibody ◽

Maternal Antibodies ◽

Childhood Immunization ◽

Serum Samples ◽

Denv Serotypes ◽

Antibody Titers ◽

Antibody Kinetics

Understanding maternal dengue virus (DENV) neutralizing antibody kinetics in infants remains timely to develop a safe and effective childhood immunization. This retrospective study evaluated the prevalence and persistence of maternal antibody titers against DENV serotypes 1 to 4 in 139 Thai infants at 2, 6, and 7 months of age, using serum samples collected in a vaccination trial ( http://clinicaltrials.gov ; NCT00197275). Neutralizing antibodies against all 4 DENV serotypes were detected in 87.8% and 22.9% of infants at 2 and 7 months, respectively. At 2 months, DENV-4 neutralizing antibody geometric mean titers were notably lower (80) compared with DENV-1 to DENV-3 (277-471). Our results corroborate previous findings that DENV-1 to DENV-4 maternal antibodies persist at 7 months despite titers decrease from 2 months onwards. As persisting maternal antibodies may inhibit immune responses in DENV-vaccinated infants, a comprehensive understanding of DENV antibody kinetics is required in the perspective of vaccine development for infants.

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Effect of a booster-dose of rabies vaccine on the duration of virus neutralizing antibody titers in bovines

Revista da Sociedade Brasileira de Medicina Tropical ◽

10.1590/s0037-86821998000400006 ◽

1998 ◽

Vol 31 (4) ◽

pp. 367-371 ◽

Cited By ~ 5

Author(s):

Avelino Albas ◽

Paulo Eduardo Pardo ◽

Albério Antonio Barros Gomes ◽

Fernanda Bernardi ◽

Fumio Honma Ito

Keyword(s):

Immune Response ◽

Neutralizing Antibodies ◽

Booster Dose ◽

Neutralization Test ◽

Neutralizing Antibody ◽

Rabies Vaccine ◽

Western Region ◽

Humoral Immune ◽

Paulo State ◽

Antibody Titers

Humoral immune response using inactivated rabies vaccine was studied in 35 nelore cross-bred bovines of western region of São Paulo state. Ninety days after vaccination, 13 (92.8%) animals presented titers 30.5IU/ml, through mouse neutralization test. After 180 days, 9 (64.3%) sera showed titers 30.5IU/ml, after 270 days, only one (7.1%) showed a titer of 0.51IU/ml, and after 360 days, all animals showed titers < 0.5IU/ml. Group of animals receiving booster dose 30 days after vaccination presented, two months after, all with titers > 0.5IU/ml. At 180 days, 17 (80.9%) sera presented titers > 0.5IU/ml; at 270 days, 15 (71.4%), with titers 30.5IU/ml and at 360 days, 4 (19.0%), with titers 30.5IU/ml. Booster-dose ensured high levels of neutralizing antibodies for at least three months, and 240 days after revaccination, 71.4% of animals were found with titers 30.5IU/ml.

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Neutralizing Antibody Responses in COVID-19 Convalescent Sera

The Journal of Infectious Diseases ◽

10.1093/infdis/jiaa673 ◽

2020 ◽

Vol 223 (1) ◽

pp. 47-55 ◽

Cited By ~ 1

Author(s):

William T Lee ◽

Roxanne C Girardin ◽

Alan P Dupuis ◽

Karen E Kulas ◽

Anne F Payne ◽

...

Keyword(s):

Neutralizing Antibodies ◽

High Titer ◽

Experimental Treatment ◽

Neutralizing Antibody ◽

Maximal Activity ◽

The United States ◽

Enzyme Linked Immunosorbent Assay ◽

United States Food ◽

Antibody Titers ◽

Antibody Levels

Abstract Passive transfer of antibodies from COVID-19 convalescent patients is being used as an experimental treatment for eligible patients with SARS-CoV-2 infections. The United States Food and Drug Administration’s (FDA) guidelines for convalescent plasma initially recommended target antibody titers of 160. We evaluated SARS-CoV-2 neutralizing antibodies in sera from recovered COVID-19 patients using plaque reduction neutralization tests (PRNT) at moderate (PRNT50) and high (PRNT90) stringency thresholds. We found that neutralizing activity significantly increased with time post symptom onset (PSO), reaching a peak at 31–35 days PSO. At this point, the number of sera having neutralizing titers of at least 160 was approximately 93% (PRNT50) and approximately 54% (PRNT90). Sera with high SARS-CoV-2 antibody levels (>960 enzyme-linked immunosorbent assay titers) showed maximal activity, but not all high-titer sera contained neutralizing antibody at FDA recommended levels, particularly at high stringency. These results underscore the value of serum characterization for neutralization activity.

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Breakthrough of SIV strain smE660 challenge in SIV strain mac239-vaccinated rhesus macaques despite potent autologous neutralizing antibody responses

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1509731112 ◽

2015 ◽

Vol 112 (34) ◽

pp. 10780-10785 ◽

Cited By ~ 21

Author(s):

Samantha L. Burton ◽

Katie M. Kilgore ◽

S. Abigail Smith ◽

Sharmila Reddy ◽

Eric Hunter ◽

...

Keyword(s):

Simian Immunodeficiency Virus ◽

Neutralizing Antibodies ◽

Rhesus Macaques ◽

Neutralizing Antibody ◽

Active Immunization ◽

Antibody Responses ◽

Challenge Virus ◽

Gm Csf ◽

Immunodeficiency Virus

Although the correlates of immunological protection from human immunodeficiency virus or simian immunodeficiency virus infection remain incompletely understood, it is generally believed that medium to high titers of serum neutralizing antibodies (nAbs) against the challenge virus will prevent infection. This paradigm is based on a series of studies in which passive transfer of HIV-specific nAbs protected rhesus macaques (RMs) from subsequent mucosal challenge with a chimeric human/simian immunodeficiency virus. However, it is unknown whether nAb titers define protection in the setting of active immunization. Here we determined serum nAb titers against breakthrough transmitted/founder (T/F) SIVsmE660-derived envelope glycoprotein (Env) variants from 14 RMs immunized with SIVmac239-based DNA-prime/modified vaccinia virus Ankara-boost vaccine regimens that included GM-CSF or CD40L adjuvants and conferred significant but incomplete protection against repeated low-dose intrarectal challenge. A single Env variant established infection in all RMs except one, with no identifiable genetic signature associated with vaccination breakthrough compared with T/F Envs from four unvaccinated monkeys. Breakthrough T/F Env pseudoviruses were potently neutralized in vitro by heterologous pooled serum from chronically SIVsmE660-infected monkeys at IC50 titers exceeding 1:1,000,000. Remarkably, the T/F Env pseudoviruses from 13 of 14 monkeys were also susceptible to neutralization by autologous prechallenge serum at in vitro IC50 titers ranging from 1:742–1:10,832. These titers were similar to those observed in vaccinated RMs that remained uninfected. These data suggest that the relationship between serum nAb titers and protection from mucosal SIV challenge in the setting of active immunization is more complex than previously recognized, warranting further studies into the balance between immune activation, target cell availability, and protective antibody responses.

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