Neutralizing Antibodies against SARS-CoV-2, Anti-Ad5 Antibodies, and Reactogenicity in Response to Ad5-nCoV (CanSino Biologics) Vaccine in Individuals with and without Prior SARS-CoV-2

This is the first study outside of clinical trials (phase I–III) evaluating the ability of the Ad5-nCoV vaccine to generate neutralizing antibodies and the factors associated with optimal or suboptimal response. In a longitudinal assay, 346 people (117 with prior COVID-19 and 229 without prior COVID-19) vaccinated with Ad5-nCoV were recruited. The percentage of neutralizing antibodies against SARS-CoV-2 (Surrogate Virus Neutralization Test) and antibodies against Ad5 (ADV-Ad5 IgG ELISA) were quantified pre and post-vaccination effects. The Ad5-nCoV vaccine induces higher neutralizing antibodies percentage in individuals with prior COVID-19 than those without prior COVID-19 (median [IQR]: 98% [97–98.1] vs. 72% [54–90], respectively; p < 0.0001). Furthermore, a natural infection (before vaccination) induces more neutralizing antibodies percentage than immunized individuals without prior COVID-19 (p < 0.01). No patient had vaccine-severe adverse effects. The age, antidepressant, and immunosuppressive treatments, reactogenicity, and history of COVID-19 are associated with impaired antibody production. The anti-Ad5 antibodies increased after 21 days of post-vaccination in all groups (p < 0.01). We recommend the application of a booster dose of Ad5-nCoV, especially for those individuals without previous COVID-19 infection. Finally, the induction of anti-Ad5 antibodies after vaccination should be considered if a booster with the same vaccine is planned.

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Self-Replicating RNA Viruses for RNA Therapeutics

Molecules ◽

10.3390/molecules23123310 ◽

2018 ◽

Vol 23 (12) ◽

pp. 3310 ◽

Cited By ~ 13

Author(s):

Kenneth Lundstrom

Keyword(s):

Clinical Trials ◽

Phase I ◽

Tumor Cells ◽

Neutralizing Antibodies ◽

Ebola Virus ◽

Vaccine Development ◽

Rna Viruses ◽

Antibody Responses ◽

Phase Iii ◽

Phase I Clinical Trials

Self-replicating single-stranded RNA viruses such as alphaviruses, flaviviruses, measles viruses, and rhabdoviruses provide efficient delivery and high-level expression of therapeutic genes due to their high capacity of RNA replication. This has contributed to novel approaches for therapeutic applications including vaccine development and gene therapy-based immunotherapy. Numerous studies in animal tumor models have demonstrated that self-replicating RNA viral vectors can generate antibody responses against infectious agents and tumor cells. Moreover, protection against challenges with pathogenic Ebola virus was obtained in primates immunized with alphaviruses and flaviviruses. Similarly, vaccinated animals have been demonstrated to withstand challenges with lethal doses of tumor cells. Furthermore, clinical trials have been conducted for several indications with self-amplifying RNA viruses. In this context, alphaviruses have been subjected to phase I clinical trials for a cytomegalovirus vaccine generating neutralizing antibodies in healthy volunteers, and for antigen delivery to dendritic cells providing clinically relevant antibody responses in cancer patients, respectively. Likewise, rhabdovirus particles have been subjected to phase I/II clinical trials showing good safety and immunogenicity against Ebola virus. Rhabdoviruses have generated promising results in phase III trials against Ebola virus. The purpose of this review is to summarize the achievements of using self-replicating RNA viruses for RNA therapy based on preclinical animal studies and clinical trials in humans.

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Evidence of neutralizing antibodies against SARS-CoV-2 in domestic cats living with owners with a history of COVID-19 in Lima, Peru

10.1101/2021.05.26.445880 ◽

2021 ◽

Author(s):

Luis M. Jara ◽

Cusi Ferradas ◽

Francesca Schiaffino ◽

Camila Sanchez-Carrion ◽

Ana Martinez ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Neutralization Test ◽

Domestic Animals ◽

Disease Prevalence ◽

Receptor Binding Domain ◽

Domestic Cats ◽

Viral Reservoirs ◽

History Of ◽

Community Transmission ◽

Disease Exposure

SARS-CoV-2 can infect a variety of wild and domestic animals worldwide. Of these, domestic cats are highly susceptible species and potential viral reservoirs. As such, it is important to investigate disease exposure in areas with active community transmission and high disease prevalence. In this report we demonstrate the presence of serum neutralizing antibodies against the receptor binding-domain (RBD) of the SARS-CoV-2 in cats whose owners had been infected with SARS-CoV-2 in Lima, Peru, using a commercial competitive ELISA SARS-CoV-2 Surrogate Virus Neutralization Test. Out of 41 samples, 17.1% (7/41) and 31.7% (13/41) were positive, using the cut-off inhibition value of 30% and 20%, respectively. Not all cats living in a single house had detectable neutralizing antibodies showing that heterogenous exposure and immune among cohabiting animals. This is the first report of SARS-COV-2 exposure of domestic cats in Lima, Peru. Further studies are required to ascertain the prevalence of SARS-COV-2 exposure among domestic cats of Lima, Peru.

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Development of specific immunity in laboratory animals after co-immunization against seasonal influenza and COVID-19

Journal of microbiology epidemiology immunobiology ◽

10.36233/0372-9311-183 ◽

2022 ◽

Vol 98 (6) ◽

pp. 648-656

Author(s):

G. M. Ignatyev ◽

I. A. Leneva ◽

A. V. Atrasheuskaya ◽

L. I. Kozlovskaya ◽

N. P. Kartashova ◽

...

Keyword(s):

Neutralizing Antibodies ◽

Seasonal Influenza ◽

Neutralization Test ◽

Elisa Test ◽

Control Measures ◽

Laboratory Animals ◽

Enzyme Linked Immunosorbent Assay ◽

Post Vaccination ◽

Specific Immunity ◽

Influenza Prevention

Introduction. In clinical practice, the differential diagnosis of COVID-19 can be challenging during the flu season, entailing serious consequences such as delays in appropriate control measures against the SARS-CoV-2 pandemic. Another problem is posed by co-infection of SARS-CoV-2 and influenza virus (IV), which significantly contributes to the severity of the COVID-19 disease. This study was aimed to explore the cross-impact of co-administration of Russian influenza and COVID-19 vaccines on development of specific immunity in laboratory animals.Materials and methods. The study was conducted on BALB/c mice. The animals were inoculated intramuscularly with the vaccine for COVID-19 prevention (CoviVac) and the vaccine for influenza prevention (Flu-M). The sera from the immunized animals were examined separately. Three IV strains were used in the hemagglutination inhibition assay. Antibodies (Abs) against SARS-CoV-2 were detected by an enzyme-linked immunosorbent assay (ELISA). The neutralization test was performed to detect virus neutralizing antibodies against SARS-CoV-2 and IV.Results. Relatively high titers of specific Abs were found in the groups of animals inoculated with one vaccine and with two vaccines concurrently. In the groups of animals inoculated with CoviVac and with two vaccines concurrently, both in the ELISA test and in the neutralization test, the average titers of specific Abs against SARSCoV- 2 did not demonstrate any statistical difference. The group of animals inoculated concurrently with two vaccines demonstrated statistically higher titers of Abs against IV after the second immunization compared to the group of animals inoculated with Flu-M.Discussion. The study has shown that post-vaccination immunity both to IV and to SARS-CoV-2 develops after co-vaccination with two vaccines. The observed enhanced post-vaccination immune response to IV in the coimmunized laboratory animals needs further research.Conclusion. The performed studies suggest the possibility of co-administration of two vaccines to prevent influenza and COVID-19.

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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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Phase I/II Clinical Trial of the Anti-Podoplanin Monoclonal Antibody Therapy in Dogs with Malignant Melanoma

Cells ◽

10.3390/cells9112529 ◽

2020 ◽

Vol 9 (11) ◽

pp. 2529

Author(s):

Satoshi Kamoto ◽

Masahiro Shinada ◽

Daiki Kato ◽

Sho Yoshimoto ◽

Namiko Ikeda ◽

...

Keyword(s):

Clinical Trial ◽

Clinical Trials ◽

Malignant Melanoma ◽

Adverse Effects ◽

Phase I ◽

Tumor Cells ◽

Antibody Therapy ◽

Human Tumor ◽

Preclinical Trial ◽

Canine Tumor

Podoplanin (PDPN), a small transmembrane mucin-like glycoprotein, is ectopically expressed on tumor cells. PDPN is known to be linked with several aspects of tumor malignancies in certain types of human and canine tumors. Therefore, it is considered to be a novel therapeutic target. Monoclonal antibodies targeting PDPN expressed in human tumor cells showed obvious anti-tumor effects in preclinical studies using mouse models. Previously, we generated a cancer-specific mouse–dog chimeric anti-PDPN antibody, P38Bf, which specifically recognizes PDPN expressed in canine tumor cells. In this study, we investigated the safety and anti-tumor effects of P38Bf in preclinical and clinical trials. P38Bf showed dose-dependent antibody-dependent cellular cytotoxicity against canine malignant melanoma cells. In a preclinical trial with one healthy dog, P38Bf administration did not induce adverse effects over approximately 2 months. In phase I/II clinical trials of three dogs with malignant melanoma, one dog vomited, and all dogs had increased serum levels of C-reactive protein, although all adverse effects were grade 1 or 2. Severe adverse effects leading to withdrawal of the clinical trial were not observed. Furthermore, one dog had stable disease with P38Bf injections. This is the first reported clinical trial of anti-PDPN antibody therapy using spontaneously occurring canine tumor models.

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Comparative kinetics of SARS-CoV-2 anti-spike protein RBD IgGs and neutralizing antibodies in convalescent and naïve recipients of the BNT162b2 mRNA vaccine versus COVID-19 patients

BMC Medicine ◽

10.1186/s12916-021-02090-6 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Ioannis P. Trougakos ◽

Evangelos Terpos ◽

Christina Zirou ◽

Aimilia D. Sklirou ◽

Filia Apostolakou ◽

...

Keyword(s):

Immune Response ◽

Neutralizing Antibodies ◽

Mononuclear Cells ◽

Natural Infection ◽

Severe Disease ◽

Vaccination Campaign ◽

Hospitalized Patients ◽

Peripheral Blood Mononuclear ◽

Post Vaccination ◽

Antibody Titers

Abstract Background Coronavirus SARS-CoV-2, the causative agent of COVID-19, has caused a still evolving global pandemic. Given the worldwide vaccination campaign, the understanding of the vaccine-induced versus COVID-19-induced immunity will contribute to adjusting vaccine dosing strategies and speeding-up vaccination efforts. Methods Anti-spike-RBD IgGs and neutralizing antibodies (NAbs) titers were measured in BNT162b2 mRNA vaccinated participants (n = 250); we also investigated humoral and cellular immune responses in vaccinated individuals (n = 21) of this cohort 5 months post-vaccination and assayed NAbs levels in COVID-19 hospitalized patients (n = 60) with moderate or severe disease, as well as in COVID-19 recovered patients (n = 34). Results We found that one (boosting) dose of the BNT162b2 vaccine triggers robust immune (i.e., anti-spike-RBD IgGs and NAbs) responses in COVID-19 convalescent healthy recipients, while naïve recipients require both priming and boosting shots to acquire high antibody titers. Severe COVID-19 triggers an earlier and more intense (versus moderate disease) immune response in hospitalized patients; in all cases, however, antibody titers remain at high levels in COVID-19 recovered patients. Although virus infection promotes an earlier and more intense, versus priming vaccination, immune response, boosting vaccination induces antibody titers significantly higher and likely more durable versus COVID-19. In support, high anti-spike-RBD IgGs/NAbs titers along with spike (vaccine encoded antigen) specific T cell clones were found in the serum and peripheral blood mononuclear cells, respectively, of vaccinated individuals 5 months post-vaccination. Conclusions These findings support vaccination efficacy, also suggesting that vaccination likely offers more protection than natural infection. Graphical abstract

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Protective levels of canine distemper virus antibody in an urban dog population using plaque reduction neutralization test

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v71i3.264 ◽

2004 ◽

Vol 71 (3) ◽

Author(s):

O.I. Oyedele ◽

D.O. Oluwayelu ◽

S.I.B. Cadmus ◽

F.D. Adu

Keyword(s):

Neutralizing Antibodies ◽

Canine Distemper Virus ◽

Neutralization Test ◽

Neutralization Assay ◽

Canine Distemper ◽

Virus Antibody ◽

Post Vaccination ◽

Blood Samples ◽

Highly Sensitive ◽

Positive Serum

Blood samples from 50 dogs were collected at three veterinary clinics in Ibadan and Abuja, Nigeria and the serum from each sample was evaluated serologically for neutralizing antibodies against canine distemper virus (CDV) by the highly sensitive plaque reduction (PRN) neutralization assay. Thirteen dogs had plaque reduction neutralization titres of 0-100, seven had titres of 100-1 000 while 30 had titres ranging from 1 000-6 000. The PRN titres of vaccinated dogs were found to be significantly higher than unvaccinated dogs. The widespread use of the highly reproducible PRN test for the evaluation of antibody response to CDV may be very important in the generation of international CDV positive serum standards that should help to improve pre-and post-vaccination testing of dogs worldwide.

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Immunogenicity and Safety Profile of COVID-19 Vaccines- A Systematic Review (Preprint)

10.2196/preprints.25396 ◽

2020 ◽

Author(s):

Reeju Maharjan ◽

Aditya Bamboria ◽

Neelam Asghar ◽

Manish Shrestha ◽

Syed W H Rizvi

Keyword(s):

Clinical Trials ◽

Adverse Effects ◽

Systematic Reviews ◽

Neutralizing Antibodies ◽

Phase Iii ◽

Effective Vaccine ◽

Efficacy And Safety ◽

Vaccine Candidates ◽

One Year ◽

Meta Analyses

BACKGROUND An effective vaccine will be important in controlling severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic. OBJECTIVE In this study, we aim to analyze the degree of immunogenicity that rises after administering different vaccines, and to study their efficacy. METHODS We systematically reviewed multiple vaccine candidates at different stages of clinical trials to prevent Coronavirus disease in 2019 (COVID-19). We reviewed literature from four major electronic databases (PubMed, MEDLINE, PubMed Central, and Google scholar) to identify studies on SARS-CoV-2 vaccine candidates. This article included studies that include clinical trials in multiple stages and systematic reviews published in 2020. We performed a quality assessment with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines for our articles. RESULTS We included a total of 19 articles. This review article has a total of 24,342 individuals. These studies show promising results regarding vaccines candidates, safety profiles, and immunogenicity with the effective generation of neutralizing antibodies and specific T-cell responses. Adverse effects range from mild to moderate, with no serious adverse effects reported. It is unclear how long the generated immunity will last, and a follow up of the study participants for an extended one-year period will be needed. CONCLUSIONS Ascertaining vaccines' efficacy and safety in vulnerable populations is essential for the general use of vaccine use. A number of these vaccines are currently under phase III or to enter phase III and may increase vaccines' efficacy and safety in different populations.

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SARS-Cov-2 Natural Infection in a Symptomatic Cat: Diagnostic, Clinical and Medical Management in a One Health Vision

Animals ◽

10.3390/ani11061640 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1640

Author(s):

Alda Natale ◽

Elisa Mazzotta ◽

Nicoletta Mason ◽

Letizia Ceglie ◽

Monica Mion ◽

...

Keyword(s):

Medical Management ◽

Neutralizing Antibodies ◽

One Health ◽

Neutralization Test ◽

Natural Infection ◽

High Titre ◽

Upper Airways ◽

Nasal Swabs ◽

High Antibody Titre

Despite the reported increase in SARS-CoV-2-infected pets, the description of the clinical features from natural infection and the medical follow up in symptomatic pets is still not sufficiently documented. This study reports the case of an indoor cat that displayed respiratory signs and a gastrointestinal syndrome, following the COVID-19 diagnosis of his owners. Thoracic radiographies were suggestive of bronchial pneumonia, while blood tests were indicative of a mild inflammatory process. Nasal and oropharyngeal swabs tested positive through RT-qPCR assays targeting SARS-CoV-2 genes 14 days after his owners tested positive for the virus. Nasal swabs persisted to be RT-qPCR positive after 31 days. Serology confirmed the presence of antibodies through ELISA, electrochemiluminescence analysis and plaque reduction neutralization test, recording a high antibody titre after 31 days. The cat improved after medical treatment and clinically recovered. This study suggests that exposure to SARS-CoV-2 could lead to a natural infection with bronchial pneumonia in cats along with a possible prolonged persistence of SARS-CoV-2 RNA in the upper airways, albeit at a low level. The cat developed neutralizing antibodies, reaching a high titre after 31 days. Further descriptions of SARS-CoV-2 naturally infected pets, their medical management and diagnostic findings would be useful to enhance knowledge about COVID-19 in susceptible animals.

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