scholarly journals Comparative immune responses of pups following modified live virus vaccinations against canine parvovirus

2019 ◽  
Vol 12 (9) ◽  
pp. 1422-1427
Author(s):  
Jayalakshmi Vasu ◽  
Mouttou Vivek Srinivas ◽  
Prabhakar Xavier Antony ◽  
Jacob Thanislass ◽  
Vijayalakshmi Padmanaban ◽  
...  
Keyword(s):  
Immune Responses ◽  
Antibody Titer ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Booster Vaccination ◽  
Primary Vaccination ◽  
Canine Parvovirus ◽  
Serum Samples ◽  
Live Virus ◽  
Antibody Titers

Background and Aim: Canine parvovirus (CPV) is the most important viral cause of enteritis and mortality in pups. Evaluation and monitoring of pre- and post-vaccine immune responses may help to determine the efficacy of the current vaccination schedule being followed in pups in India. This study aimed to evaluate and monitor the pre- and post-vaccine immune responses of CPV vaccinated pups using hemagglutination inhibition (HI) assay. The neutralizing antibody titer levels were also detected using serum neutralization test (SNT). Materials and Methods: The pups were categorized into two groups, the double booster and the single booster groups. In this study, serum samples were subjected to HI and SNT for measuring the CPV antibody titer at frequent intervals for up to 6 months from 27 healthy pups following primary and booster CPV vaccinations. Results: The antibody titers in double booster pups reached their peaks at the 21st day after the second booster vaccination with a geometric mean (GM) of 3.57. The antibody titers in single booster pups reached their peaks at the 21st day after the first booster vaccination with a lower GM of 3.18. Conclusion: The double booster pups maintained a higher immune response throughout the period of the study compared to single booster pups though the difference in titers was not statistically significant. SNT results indicated that the raised antibody titer was also able to yield virus-neutralizing antibodies. No interfering maternally derived antibodies were found in the pups at the age of primary vaccination (45th day) in our study. Therefore, the second booster vaccination may be useful in maintaining the protective titer for a prolonged period.

scholarly journals Serological response to rabies virus induced by commercial vaccines in cattle

2017 ◽  
Vol 47 (10) ◽  
Author(s):  
Mathias Martins ◽  
João Motta de Quadros ◽  
Eduardo Furtado Flores ◽  
Rudi Weiblen
Keyword(s):  
Rabies Virus ◽  
Neutralizing Antibodies ◽  
Vaccine Dose ◽  
Booster Vaccination ◽  
Serological Response ◽  
Serum Samples ◽  
Anamnestic Response ◽  
Post Vaccination ◽  
Antibody Titers ◽  
One Year

ABSTRACT: The antibody response to rabies virus (RABV) induced by commercial vaccines in heifers was investigated. For this, 84 heifers were vaccinated twice (30 days interval) with each of four vaccines (G1 = 14 animals; G2 = 24; G3 = 22 and G4 = 24) and received a booster vaccination 360 days later. Serum samples collected at different intervals after vaccination and 30 days after booster were submitted to a virus neutralizing (VN) assay for RABV antibodies. Thirty days after the second vaccine dose, 92% of the immunized animals presented VN titers ≥0.5UI/mL (geometric medium titers [GMT] 1.7 to 3.8UI/mL). At the day of the booster (360 days post-vaccination); however, the percentage of animals harboring antibody titers ≥0.5UI/mL had dropped to 31% (0-80% of the animals, depending on the vaccine), resulting in lower GMT (0.1 to 0.6UI/mL). Booster vaccination at day 360 resulted in a detectable anamnestic response in all groups, resulting in 83% of animals (65 to 100%) harboring VN titers ≥0.5UI/mL thirty days later (GMT 0.6 to 4.3UI/mL). These results indicated that these vaccines were able to induce an adequate anti-RABV response in all animals after prime vaccination (and after booster as well). However, the titers decreased, reaching titers <0.5UI/mL in approximately 70% of animals within the interval before the recommended booster. Thus, booster vaccination for rabies in cattle using the current vaccines should be performed before the recommended one-year interval, as to maintain neutralizing antibodies levels in most vaccinated animals.

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

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.

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

2019 ◽  
Vol 31 (4) ◽  
pp. 288-295 ◽  
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.

scholarly journals Impaired Humoral Response to Vaccines among HIV-Exposed Uninfected Infants

2011 ◽  
Vol 18 (9) ◽  
pp. 1406-1409 ◽  
Author(s):  
Beatriz Mariana Abramczuk ◽  
Taís Nitsch Mazzola ◽  
Yara Maria Franco Moreno ◽  
Tatiane Queiroz Zorzeto ◽  
Wagner Quintilio ◽  
...  
Keyword(s):  
Hepatitis B ◽  
Immune Responses ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Humoral Response ◽  
Vaccine Response ◽  
Serum Samples ◽  
Hiv Exposed ◽  
Exposed Uninfected

ABSTRACTLittle is known about the vaccine protective response for infants born from HIV-infected mothers. We evaluated the antibody response to hepatitis B, tetanus, and diphtheria vaccine in vertically HIV-exposed uninfected infants and compared them to those of control infants not exposed to the virus. The quantitative determination of specific neutralizing antibodies against hepatitis B, diphtheria, and tetanus were performed blindly on serum samples. The results showed that 6.7% of the HIV-exposed uninfected individuals were nonresponders to hepatitis B vaccine (anti-HBs titer, <10 mIU/ml), and 64.4% were very good responders (anti-HBs titer, ≥1,000 mIU/ml), whereas only 3.6% of the nonexposed infants were nonresponders (χ2=10.93; 1 df). The HIV-exposed uninfected infants showed protective titers for diphtheria and tetanus but lower geometric mean anti-tetanus titers compared to those of the HIV-unexposed infants. Our data point to the necessity of evaluating vaccine immune responses in these children and reinforced that alterations in lymphocyte numbers and functions reported for newborns from HIV-infected mothers interfere with the vaccine response.

scholarly journals Neutralization of SARS-CoV-2 Omicron variant by sera from BNT162b2 or Coronavac vaccine recipients

2021 ◽  
Author(s):  
Lu Lu ◽  
Bobo Mok ◽  
Linlei Chen ◽  
Jacky Chan ◽  
Owen Tsang ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
World Health ◽  
Whole Genome Sequence ◽  
Live Virus ◽  
Significant Difference ◽  
Antibody Titers ◽  
Ancestral Virus ◽  
Health Organization

Background The SARS-CoV-2 Omicron variant, designated as a Variant of Concern(VOC) by the World Health Organization, carries numerous spike protein mutations which have been found to evade neutralizing antibodies elicited by COVID-19 vaccines. The susceptibility of Omicron variant by vaccine-induced neutralizing antibodies are urgently needed for risk assessment. Methods Omicron variant strains HKU691 and HKU344-R346K were isolated from patients using TMPRSS2-overexpressing VeroE6 cells. Whole genome sequence was determined using nanopore sequencing. Neutralization susceptibility of ancestral lineage A virus and the Omicron, Delta and Beta variants to sera from 25 BNT162b2 and 25 Coronavac vaccine recipients was determined using a live virus microneutralization assay. Results The Omicron variant strain HKU344-R346K has an additional spike R346K mutation, which is present in 8.5% of strains in GISAID database. Only 20% and 24% of BNT162b2 recipients had detectable neutralizing antibody against the Omicron variant HKU691 and HKU344-R346K, respectively, while none of the Coronavac recipients had detectable neutralizing antibody titer against either Omicron isolates. For BNT162b2 recipients, the geometric mean neutralization antibody titers(GMT) of the Omicron variant isolates(5.43 and 6.42) were 35.7-39.9-fold lower than that of the ancestral virus(229.4), and the GMT of both omicron isolates were significantly lower than those of the beta and delta variants. There was no significant difference in the GMT between HKU691 and HKU344-R346K. Conclusions Omicron variant escapes neutralizing antibodies elicited by BNT162b2 or CoronaVac. The additional R346K mutation did not affect the neutralization susceptibility. Our data suggest that the Omicron variant may be associated with lower COVID-19 vaccine effectiveness.

scholarly journals Serology in Children with Multisystem Inflammatory Syndrome (MIS-C) associated with COVID-19

2020 ◽  
Author(s):  
Christina A. Rostad ◽  
Ann Chahroudi ◽  
Grace Mantus ◽  
Stacey A. Lapp ◽  
Mehgan Teherani ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Limit Of Detection ◽  
Geometric Mean ◽  
Neutralization Assay ◽  
Adverse Outcomes ◽  
Igg Antibody ◽  
Live Virus ◽  
Lengths Of Stay ◽  
Antibody Titers ◽  
Inflammatory Syndrome

Objectives: We aimed to measure SARS-CoV-2 serologic responses in children hospitalized with multisystem inflammatory syndrome (MIS-C) compared to COVID-19, Kawasaki Disease (KD) and other hospitalized pediatric controls. Methods: From March 17, 2020 - May 26, 2020, we prospectively identified hospitalized children at Children's Healthcare of Atlanta with MIS-C (n=10), symptomatic PCR-confirmed COVID-19 (n=10), KD (n=5), and hospitalized controls (n=4). With IRB approval, we obtained prospective and residual blood samples from these children and measured SARS-CoV-2 spike (S) receptor binding domain (RBD) IgM and IgG binding antibodies by quantitative ELISA and SARS-CoV-2 neutralizing antibodies by live-virus focus reduction neutralization assay. We statistically compared the log-transformed antibody titers among groups and performed correlation analyses using linear regression. Results: All children with MIS-C had high titers of SARS-CoV-2 RBD IgG antibodies, which correlated strongly with neutralizing antibodies (R2=0.667, P<0.001). Children with MIS-C had significantly higher SARS-CoV-2 RBD IgG antibody titers (geometric mean titer [GMT] 6800, 95%CI 3495-13231) than children with COVID-19 (GMT 626, 95%CI 251-1563, P<0.001), children with KD (GMT 124, 95%CI 91-170, P<0.001) and other hospitalized pediatric controls (GMT 85 [all below assay limit of detection], P<0.001). All children with MIS-C also had detectable RBD IgM antibodies, indicating recent SARS-CoV-2 infection. RBD IgG titers correlated with erythrocyte sedimentation rate (ESR) (R2=0.512, P<0.046) and with hospital and ICU lengths of stay (R2=0.590, P=0.010). Conclusion: Quantitative SARS-CoV-2 RBD antibody titers may have a role in establishing the diagnosis of MIS-C, distinguishing it from other similar clinical entities, and stratifying risk for adverse outcomes.

RESPIRATORY SYNCYTIAL VIRUS NEUTRALIZING ANTIBODIES IN PERSONS RESIDING IN CHICAGO, ILLINOIS

PEDIATRICS ◽  
1964 ◽  
Vol 34 (6) ◽  
pp. 761-770
Author(s):  
Marc Beem ◽  
Rosalie Egerer ◽  
Julia Anderson
Keyword(s):  
Virus Infection ◽  
Antibody Titer ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Indirect Evidence ◽  
Neutralizing Antibody ◽  
Single Strain ◽  
Wild Strains ◽  
Antibody Titers ◽  
Syncytial Virus

The R.S. virus neutralization test was examined in terms of several factors bearing on the consistency and specificity of antibody response to a single strain (Randall) of this virus. It was found that this virus detected significant rises in antibody titer in 90% of 30 patients over 6 months of age who were infected with wild strains of R.S. virus between the years 1958 and 1962. Heterologous neutralizing antibodies to R.S. virus did not occur following human infections with various myxoviruses, adenoviruses, enteroviruses and herpesvirus. Indirect evidence was presented indicating that tile neutralizing activity of human serums is due to specific antibody and not due to non-specific, heat stable neutralizing substance. The titer of R.S. neutralizing antibodies was determined in the serums of 26 parturient mothers, and their 27 newborn babies, and 186 other individuals between the ages of 6 months and 69 years. Longitudinal observations of antibody titer were also conducted on 12 other infants. Neutralizing antibodies to R.S. virus were found to reach the term fetus at undiminished titer. In the longitudinal observations, serum neutralizing antibody titers were found to fall during the first months of life, decreasing by half in an average time of 43 days. Neutralizing antibodies, actively formed in response to R.S. virus infection, were observed to occur with rapidly increasing frequency in relation to age in subjects older than 6 months. These serologic findings indicated that among individuals residing in the metropolitan Chicago area, R.S. virus infection has been experienced by many during the first 2 years of life, most by school age, and all by 7 years of age. Geometric mean antibody titers were found to show a small, but probably significant, increase with age. The restriction of low titer reactors to pre-school children was noted. These serologic findings were interpreted as evidence that re-infections with R.S. virus occur, perhaps quite commonly.

scholarly journals Immunogenicity of a commercial Salmonella enteritidis vaccine in layer birds

2019 ◽  
Author(s):  
F. Nasrin ◽  
M. S. R. Khan ◽  
M. A. Islam
Keyword(s):  
Immune Response ◽  
Antibody Titer ◽  
Salmonella Enteritidis ◽  
Booster Vaccination ◽  
Primary Vaccination ◽  
Vaccination Schedule ◽  
Post Vaccination ◽  
Layer Chicken ◽  
Antibody Titers ◽  
Group A

Background: The aged birds are known to induce good immunity against Salmonella enteritidisas compared to young. To judge this hypothesis layer birds at 42 and 49 days old were vaccinated with AVI Pro®109SE4 vaccine and immune response in terms of antibody titers was measured. Methods: A composition of antibody production in vaccinated chicken was performed following a usual vaccination schedule with a newly suggested vaccination schedule. To study the immunogenicity of vaccine a total of 15 chickenswere divided into three groups. Each group comprised of 5 layer chicken. Chicken in group A and B were vaccinated with AVI Pro®109SE4 vaccine with a dose of 0.5ml/bird through SC route. Primary vaccination was performed at 42 days and 49 days of age respectively and booster vaccination was given at 72 days and 79 days of age respectively. Blood samples were collected to obtain sera from each chicken at every 7 days interval up to 93 days post vaccination for the determination of antibody titer using microplate agglutination test. Results: Highest mean antibody titers were recorded as179.20±70.11and 307.20±114.49 in birds of group A and B respectively. The highest mean antibody titer was recorded as 307.20±114.49 in chicken at 21 days post vaccination with AVI Pro®109SE4 vaccine using newly suggested schedule as compared to usual schedule of vaccination. Conclusions: Primary vaccination at birds at 49 days (newly planned vaccination schedule) of age induced better immune response as compared to birds vaccinated at 42 days of age.

scholarly journals Immunogenicity in sheep of Uruguayan commercial vaccines against bovine alphaherpesvirus 1, 5 and bovine pestiviruses

2020 ◽  
Vol 50 (4) ◽  
Author(s):  
Ingryd Merchioratto ◽  
Alana de Almeida Aurélio ◽  
Janice Machado Villela ◽  
Nicole Vieira Stone ◽  
Isac Junior Roman ◽  
...  
Keyword(s):  
Antibody Response ◽  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Neutralizing Antibody ◽  
Serological Response ◽  
Serum Samples ◽  
Post Vaccination ◽  
Immunological Responses ◽  
Antibody Titers ◽  
Low Levels

ABSTRACT: The serological responses induced by four commercial inactivated Uruguayan vaccines against bovine alphaherpesviruses (BoHV)-1 and -5 and bovine pestiviruses (BVDV-1, BVDV-2, and HoBiPeV) were evaluated in sheep. Thirty-seven sheep were immunized twice (day 0 and 25) and their serum samples were tested at different intervals (days 0, 25, 40, 60, and 90) post-vaccination (PV). Among the four vaccines tested, only one (G4) could induce the production of moderate neutralizing antibody titers against BoHV-1 and -5 and BVDV-1 and -2. The G3 vaccine showed a neutralizing serological response against the bovine alphaherpesviruses only. The G1 and G2 vaccines produced extremely low levels of antibodies in a few vaccinated animals only (geometric mean titers (GMT) 2.2). Similar levels of immunological responses were induced by the G4 vaccine against BoHV-1 and -5, and titers of neutralizing antibodies induced in approximately 70% of the animals are known to confer protection (GMT > 8). For bovine pestiviruses, the vaccine stimulated response of G4 against BVDV-2 was higher compared to that against BVDV-1, and extremely low for HoBiPeV. The peak of neutralizing antibodies to BoHV-1 and BVDV-1 was observed on days 40 and 60 PV, respectively. Thereafter, a remarkably decrease in neutralizing antibody response was observed at day 90 PV. These results demonstrated that tested commercial Uruguayan vaccines did not induce a serological response of adequate magnitude and duration. Thus, it is important to periodically review formulations and compositions of commercial vaccines against bovine alphaherpesviruses and pestiviruses.

scholarly journals Recombinant subunits of SARS-CoV-2 spike protein as vaccine candidates to elicit neutralizing antibodies

2021 ◽  
Author(s):  
Faezeh Noorabad ghahroodi ◽  
Saeed Khalili ◽  
Mohammad Javad Rasaee
Keyword(s):  
Recombinant Proteins ◽  
In Silico ◽  
Neutralizing Antibodies ◽  
Spike Protein ◽  
Serum Samples ◽  
Strong Immune Response ◽  
Live Virus ◽  
Vaccine Candidates ◽  
Antibody Titers

Abstract The spike protein has been reported as one of the most critical targets for vaccine design strategies against the SARS-COV-2 infection. Hence, we have designed, produced, and evaluated the potential use of recombinant proteins derived from spike protein as vaccine candidates capable of neutralizing SARS-COV-2 virus. In silico tools were used to design spike-based subunit recombinant proteins (P1, P2, and P3). These proteins were checked for their ability to be identified by the anti-SARS-COV-2 antibodies by exposing them to Covid-19 serum samples. The proteins were then injected into mice and rabbits and the antibody titers were measured for 170 days. The virus neutralization test (VNT) was performed to analyze the obtained antibodies for their neutralization efficiency. The antibodies that existed in the serum of COVID-19 patients have identified the designed proteins. The anti-spike antibody titer was increased in the animals injected with recombinant proteins. The VNT results revealed that the produced antibodies could neutralize the cultured live virus. The long-lasting antibody titers (130 and 170 days for rabbit and mouse groups) indicated the elicitation of a strong immune response by the recombinant proteins. Subunit vaccines could also be considered as robust tools for effective vaccination against COVID-19. Using a combination of in silico, in vitro, and in vivo experiments, it was shown that the injection of spike-based recombinant proteins could stimulate long-lasting and neutralizing antibody responses. Further evaluation of the recombinant proteins examined in our studies in higher primates and human would elucidate their true potentials.

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