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 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 BNT162b2 SARS-CoV-2 Vaccination Elicits High Titers of Neutralizing Antibodies to Both B.1 and P.1 Variants in Previously Infected and Uninfected Subjects

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 896
Author(s):  
Ilaria Vicenti ◽  
Francesca Gatti ◽  
Renzo Scaggiante ◽  
Adele Boccuto ◽  
Daniela Zago ◽  
...  
Keyword(s):  
Health Care ◽  
Health Care Workers ◽  
Neutralizing Antibodies ◽  
Vaccine Dose ◽  
Neutralizing Antibody ◽  
Post Vaccination ◽  
Care Workers ◽  
Antibody Titers ◽  
Cross Neutralization ◽  
Highly Correlated

We aimed to investigate neutralizing antibody titers (NtAbT) to the P.1 and B.1 SARS-CoV-2 variants in a cohort of healthy health care workers (HCW), including 20 previously infected individuals tested at baseline (BLinf, after a median of 298 days from diagnosis) and 21 days after receiving one vaccine dose (D1inf) and 15 uninfected subjects tested 21 days after the second-dose vaccination (D2uninf). All the subjects received BNT162b2 vaccination. D1inf NtAbT increased significantly with respect to BLinf against both B.1 and P.1 variants, with a fold-change significantly higher for P.1. D1inf NtAbT were significantly higher than D2uninf NtAbT, against B.1 and P.1. NtAbT against the two strains were highly correlated. P.1 NtAbT were significantly higher than B.1 NtAbT. This difference was significant for post-vaccination sera in infected and uninfected subjects. A single-dose BNT162b2 vaccination substantially boosted the NtAb response to both variants in the previously infected subjects. NtAb titers to B.1 and P.1 lineages were highly correlated, suggesting substantial cross-neutralization. Higher titers to the P.1 than to the B.1 strain were driven by the post-vaccination titers, highlighting that cross-neutralization can be enhanced by vaccination.

scholarly journals Antibodies against rabies virus in dogs with and without history of vaccination in Santa Maria - RS - Brazil

2017 ◽  
Vol 47 (11) ◽  
Author(s):  
Karina Gonzalez Fernandes ◽  
Mathias Martins ◽  
Bruna Portolan Amaral ◽  
Juliana Felipetto Cargnelutti ◽  
Rudi Weiblen ◽  
...  
Keyword(s):  
Rabies Virus ◽  
Neutralizing Antibodies ◽  
Neutralizing Antibody ◽  
World Health ◽  
Serum Samples ◽  
Antibody Titers ◽  
Group A ◽  
Group B ◽  
Santa Maria ◽  
Rabies Vaccination

ABSTRACT: The present study investigated the frequency and magnitude of neutralizing antibodies to rabies virus (RABV) in dogs with and without historic of vaccination in Santa Maria/RS. Group A included serum samples from 440 dogs with recent historic of vaccination against rabies, obtained during the 2015 rabies vaccination campaign. Group B included 300 serum samples from dogs submitted to the Veterinary Hospital of the Universidade Federal de Santa Maria in 2015, whose historic of rabies vaccination was unknown. Serum samples were submitted to the rapid fluorescent focus inhibition test (RFFIT) to detect neutralizing antibodies against RABV. In group A, 70.6% (310/440) of the samples had neutralizing antibody titers ≥0.5 international units per milliliter (IU mL-1), considered an indicative of protection against rabies by the World Health Organization. However, approximately 30% of the dogs did not contain antibodies in adequate levels. In group B, 42.3% (127/300) of the samples contained neutralizing antibody titers ≥0.5IU mL-1 and 57.7% (173/300) were negative or contained titers below of the value considered immunized. These results demonstrate that an important proportion of vaccinated dogs (~30%) did not develop adequate antibody levels, mainly those receiving a single vaccine dose. Serologic testing of animals with unknown historic of vaccination revealed relatively low vaccine coverage in the general dog population. Thus, reformulation of immunization strategies - especially the recommendation of a boost vaccination 30 days after the primary dose - and extension of vaccination campaigns are necessary to reach adequate levels and coverage of immunity against RABV in the canine population.

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 High correlation between binding IgG (anti-RBD/S) and neutralizing antibodies against SARS-CoV-2 six months after vaccination

2021 ◽  
Author(s):  
Raquel Guiomar ◽  
Ana Joao Santos ◽  
Aryse Melo ◽  
Ines Costa ◽  
Rita Matos ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Geometric Mean ◽  
Vaccine Dose ◽  
Care Work ◽  
Vaccine Uptake ◽  
Serum Samples ◽  
Health Care Work ◽  
Antibody Titers ◽  
Dose Vaccine

Vaccination is considered the most important measure to control the COVID-19 pandemic. Extensive fol-low-up studies with distinct vaccines and populations are able to promote robust and reliable data to better understand the effectiveness of this pharmacologic strategy. In this sense, we present data regarding binding and neutralizing antibodies throughout time, from vaccinated and previously infected (PI) health care work-ers (HCW) in Portugal. We analyzed serum samples of 132 HCW, vaccinated and with previous SARS-CoV-2 infection. Samples were collected before vaccination (baseline, M1), at second dose vaccine uptake (M2), and 25-70 days (M3) and 150-210 days (M4) after the second dose for vaccinated individuals. The IgG (anti-RBD/S) antibody geometric mean titer found on vaccinated HCW at M2 (814.7 AU/ml; 95% CI 649.8-1021.5) were sig-nificantly higher than those found on PI HCW at recruitment (M1) (252.6 AU/ml; 95% CI 108.7 - 587.1), and the neutralizing antibodies (nAb) were similar between these groups, 93.2 UI/ml (95% CI 73.2- 118.5) vs. 84.1 UI/ml (95% CI 40.4-155.9), respectively. We detected about 10-fold higher IgG (anti-RBD/S) antibodies titers in M3 when compared with M2, with a slightly but significant decrease in titers from 36 days after the second dose vaccine uptake. The increase of nAb titers were correlated with IgG (anti-RBD/S) antibodies titers, how-ever, contrasting to IgG (anti-RBD/S) antibodies titers, we did not detect a decrease in nAb titer from 36 days after a second vaccine dose uptake. At M4, was observed a decrease of 8-fold in binding IgG (anti-RBD/S) and nAb. No significant differences in antibody titers were observed by sex, age or chronic diseases. Our results suggest that IgG (anti-RBD/S) antibodies titers and nAb titers could be correlated, but ongoing follow up of the cohort, is required to better understand this correlation, and the duration of the immune response.

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

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.

scholarly journals Evaluation of determinants of the serological response to the split-inactivated influenza vaccine

2021 ◽  
Author(s):  
Shaohuan Wu ◽  
Ted M. Ross ◽  
Michael A. Carlock ◽  
Elodie Ghedin ◽  
Hyungwon Choi ◽  
...  
Keyword(s):  
Influenza Vaccine ◽  
Regression Models ◽  
Seasonal Influenza ◽  
Vaccine Dose ◽  
Serological Response ◽  
Linear Regression Models ◽  
Negative Effects ◽  
Categorical Response ◽  
One Year ◽  
The Impact

AbstractThe seasonal influenza vaccine is only effective in half of the vaccinated population. To identify determinants of vaccine efficacy, we used data from >1,300 vaccination events to predict the response to vaccination measured as seroconversion as well as hemagglutination inhibition (HAI) levels one year after. We evaluated the predictive capabilities of age, body mass index (BMI), sex, race, comorbidities, prevaccination history, and baseline HAI titers, as well as vaccination month and vaccine dose in multiple linear regression models. The models predicted the categorical response for >75% of the cases in all subsets with one exception. Prior vaccination, baseline titer level, and age were the strongest determinants on seroconversion, all of which had negative effects. Further, we identified a gender effect in older participants, and an effect of vaccination month. BMI played a surprisingly small role, likely due to its correlation with age. Comorbidities, vaccine dose, and race had negligible effects. Our models can generate a new seroconversion score that is corrected for the impact of these factors which can facilitate future biomarker identification.

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 Seroprevalence of measles antibodies and factors associated with susceptibility: a national survey in Mexico using a plaque reduction neutralization test

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
José Luis Díaz-Ortega ◽  
Elizabeth Ferreira-Guerrero ◽  
Luis Pablo Cruz-Hervert ◽  
Guadalupe Delgado-Sánchez ◽  
Leticia Ferreyra-Reyes ◽  
...  
Keyword(s):  
National Survey ◽  
Vaccine Dose ◽  
Effective Vaccine ◽  
Sample Population ◽  
Serum Samples ◽  
Nutrition Survey ◽  
Factors Associated ◽  
Measles Antibodies ◽  
Antibody Titers ◽  
Increased Susceptibility

Abstract Measles continues to be one of the leading causes of child mortality worldwide, even though a highly effective vaccine has existed for more than 40 years. We aimed to describe the seroprevalence of measles antibodies in Mexico in 2012 and the risk factors associated with susceptibility. A total of 7,785 serum samples were analyzed from the National Health and Nutrition Survey in Mexico. This national survey is representative of the general population, including noninstitutionalized adult, adolescent, and child populations. Antibody titers were classified into protective (> 120 mIU/mL) or susceptible (≤ 120 mIU/mL) levels. The weighted seroprevalence and susceptibility of the overall population were 99.37% (95% CI 99.07–99.58) and 0.63% (95% CI 0.42–0.93), respectively. Among 1-to-4-year-old children, 2.18% (95% CI 1.36–3.48) were susceptible to measles. Among adolescents and young adults, the prevalence of susceptibility was as follows: those 15–19 years of age had a prevalence of 0.22% (95% CI 0.09–0.57), and those 30–39 years of age had a prevalence of 1.17% (95% CI 0.47–2.85). Susceptibility was associated with young age, living in Mexico City, living in crowded households and unknown or nonvaccinated status among 1- to 5-year-old children. Although the overall sample population seroprevalence for measles is above 95%, increased susceptibility among younger children signals the importance of the timely administration of the first vaccine dose at 12 months of age. Furthermore, increased susceptibility among specific subgroups indicates the need to reinforce current vaccination policies, including the immunization of unvaccinated or incompletely vaccinated individuals from 10 to 39 years of age.

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