scholarly journals Optimization of rabies (Rhabdoviridae: Lyssavirus) dog vaccination schedule using a mathematical model

2021 ◽  
Vol 66 (5) ◽  
pp. 354-367
Author(s):  
V. A. Lobanova ◽  
V. I. Klyukina

Introduction. Most cases of human rabies are caused by dog (Canis lupus familiaris) bites. Therefore, the implementation of vaccination programs of these animals is one of the urgent tasks.The work aims to identify the factors influencing the production of antirabies virus-neutralizing antibodies (VNAs) in vaccinated dogs, and to formulate recommendations for adjusting the vaccination schedule using mathematical modeling (MM).Material and methods. We used a fixed-effects modeling procedure to estimate the two-compartment model parameters using log-transformed data (obtained by RFFIT, rapid fluorescent focus inhibition test; and FAVN, fluorescent antibody virus-neutralization test) on the VNAs levels in the serum of vaccinated dogs.Results. More vigorous immune response after a two-dose primary vaccination is formed in juvenile dogs at the age of 3 months to 1 year compared to the adult dogs. Following the primary vaccination and revaccination 1 year after, VNAs were produced more intensively in adult stray dogs than in domestic dogs.Discussion. The short-term immune response observed in dogs aged up to 3 months is due to the presence of colostral antibodies and the active growth of the organism at this age. The results of our study confirm that most of the dogs have a level of antirabies VNAs of ≥0.5 IU/ml up to two or more years following immunization. However, only regular annual revaccination ensures the protective VNAs level in animals that responded poorly to vaccination due to various factors.Conclusion. The following antirabies vaccination schedule is recommended: primary vaccination of the dog at the age of 3 months up to 1 year with 1–2 month intervals, then revaccination annually. This work also demonstrates the possibility of a wider application of MM methods for solving problems of vaccine prevention.

2018 ◽  
Vol 38 (11) ◽  
pp. 2109-2116
Author(s):  
Lina María Trujillo-Rojas ◽  
Marlén Martínez-Gutierrez ◽  
Julian Ruiz-Saenz

ABSTRACT: Rabies is an incurable and fatal progressive viral encephalomyelitis that causes approximately 61,000 deaths a year globally mainly by dog bites, which show the importance of anti-rabies vaccination in dogs to achieve elimination of the disease. In Colombia, multiple cases of human rabies transmitted by dogs and cats have been reported since 1999, showing an increased significance of cats in the transmission of rabies, mainly in rabies of wild origin. Therefore, the aim of the present study was to evaluate the development of neutralizing antibodies in dogs and cats during the mass vaccination campaign of the second half of 2015 in the city of Bucaramanga. For this purpose, a descriptive cross-sectional study with convenience sampling was conducted in 382 dogs and cats (295 dogs, 87 cats), and an evaluation of the humoral immune response of the animals was performed by quantitative ELISA. The prevalence of optimal neutralizing antibodies (>0.5 IU/ml) was only 32.76% (95% CI=28.05-37.46%) in the entire population studied and most of the animals did not have an adequate response to the vaccination, or seroconversion was not detected on them (65.45-95% confidence interval, CI=60.68-70.21%). Significant difference was found between the neutralizing antibody titers in cats and dogs, with a higher neutralizing response in cats. In conclusion, although mass vaccination campaigns for dogs and cats are the most important measure to interrupt virus circulation among the animals, achievement of a good neutralizing immune response in the animals is useful to demonstrate that vaccination has been successful, allowing the maintenance of the required minimum levels of population immunity. These results will allow the implementation of corrective measures in Bucaramanga to achieve better seroconversion rates. Other cities are expected to implement similar seroconversion assessments to verify the quality of effective anti-rabies vaccination in animal populations.


2019 ◽  
Author(s):  
F. Nasrin ◽  
M. S. R. Khan ◽  
M. A. Islam

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.


2021 ◽  
Author(s):  
Alessio Mazzoni ◽  
Nicoletta Di Lauria ◽  
Laura Maggi ◽  
Lorenzo Salvati ◽  
Anna Vanni ◽  
...  

AbstractCharacterizing the adaptive immune response to COVID-19 vaccination in individuals who recovered from SARS-CoV-2 infection may define current and future clinical practice. To determine the effect of two doses BNT162b2 mRNA COVID-19 vaccination schedule in individuals who recovered from COVID-19 (ex COVID-19) compared to naïve subjects we evaluated SARS-CoV-2 spike-specific T and B cell responses, as well as specific IgG, IgM and neutralizing antibodies titres in 22 individuals who received BNT162b2 mRNA COVID-19 vaccine, 11 of which had a previous history of SARS-CoV-2 infection. Evaluations were performed before vaccination and then weekly until 7 days post second injection. Data obtained clearly showed that one vaccine dose is sufficient to increase both cellular and humoral immune response in ex COVID-19 subjects without any additional improvement after the second dose. On the contrary, the second dose is mandatory in naïve ones to further enhance the response. These results question whether a second vaccine jab in ex COVID-19 subjects is required and indicate that millions of vaccine doses may be redirected to naïve individuals, thus shortening the time to reach herd immunity.


2020 ◽  
Vol 20 (13) ◽  
pp. 1214-1234 ◽  
Author(s):  
Md. Tanvir Kabir ◽  
Md. Sahab Uddin ◽  
Bijo Mathew ◽  
Pankoj Kumar Das ◽  
Asma Perveen ◽  
...  

Background: Alzheimer's disease (AD) is a chronic neurodegenerative disorder and the characteristics of this devastating disorder include the progressive and disabling deficits in the cognitive functions including reasoning, attention, judgment, comprehension, memory, and language. Objective: In this article, we have focused on the recent progress that has been achieved in the development of an effective AD vaccine. Summary: Currently, available treatment options of AD are limited to deliver short-term symptomatic relief only. A number of strategies targeting amyloid-beta (Aβ) have been developed in order to treat or prevent AD. In order to exert an effective immune response, an AD vaccine should contain adjuvants that can induce an effective anti-inflammatory T helper 2 (Th2) immune response. AD vaccines should also possess the immunogens which have the capacity to stimulate a protective immune response against various cytotoxic Aβ conformers. The induction of an effective vaccine’s immune response would necessitate the parallel delivery of immunogen to dendritic cells (DCs) and their priming to stimulate a Th2-polarized response. The aforesaid immune response is likely to mediate the generation of neutralizing antibodies against the neurotoxic Aβ oligomers (AβOs) and also anti-inflammatory cytokines, thus preventing the AD-related inflammation. Conclusion: Since there is an age-related decline in the immune functions, therefore vaccines are more likely to prevent AD instead of providing treatment. AD vaccines might be an effective and convenient approach to avoid the treatment-related huge expense.


Vaccines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 700
Author(s):  
Franziska Neumann ◽  
Ruben Rose ◽  
Janine Römpke ◽  
Olaf Grobe ◽  
Thomas Lorentz ◽  
...  

The humoral immunity after SARS-CoV-2 infection or vaccination was examined. Convalescent sera after infection with variants of concern (VOCs: B.1.1.7, n = 10; B.1.351, n = 1) and sera from 100 vaccinees (Pfizer/BioNTech, BNT162b2, n = 33; Moderna, mRNA-1273, n = 11; AstraZeneca, ChAdOx1 nCoV-19/AZD1222, n = 56) were tested for the presence of immunoglobulin G (IgG) directed against the viral spike (S)-protein, its receptor-binding domain (RBD), the nucleoprotein (N) and for virus-neutralizing antibodies (VNA). For the latter, surrogate assays (sVNT) and a Vero-cell based neutralization test (cVNT) were used. Maturity of IgG was determined by measuring the avidity in an immunoblot (IB). Past VOC infection resulted in a broad reactivity of anti-S IgG (100%), anti-RBD IgG (100%), and anti-N IgG (91%), while latter were absent in 99% of vaccinees. Starting approximately two weeks after the first vaccine dose, anti-S IgG (75–100%) and particularly anti-RBD IgG (98–100%) were detectable. After the second dose, their titers increased and were higher than in the convalescents. The sVNT showed evidence of VNA in 91% of convalescents and in 80–100%/100% after first/second vaccine dose, respectively. After the second dose, an increase in VNA titer and IgGs of high avidity were demonstrated by cVNT and IB, respectively. Re-vaccination contributes to a more robust immune response.


2009 ◽  
Vol 83 (7) ◽  
pp. 3228-3237 ◽  
Author(s):  
François-Loic Cosset ◽  
Philippe Marianneau ◽  
Geraldine Verney ◽  
Fabrice Gallais ◽  
Noel Tordo ◽  
...  

ABSTRACT The cell entry and humoral immune response of the human pathogen Lassa virus (LV), a biosafety level 4 (BSL4) Old World arenavirus, are not well characterized. LV pseudoparticles (LVpp) are a surrogate model system that has been used to decipher factors and routes involved in LV cell entry under BSL2 conditions. Here, we describe LVpp, which are highly infectious, with titers approaching those obtained with pseudoparticles displaying G protein of vesicular stomatitis virus and their the use for the characterization of LV cell entry and neutralization. Upon cell attachment, LVpp utilize endocytic vesicles for cell entry as described for many pH-dependent viruses. However, the fusion of the LV glycoproteins is activated at unusually low pH values, with optimal fusion occurring between pH 4.5 and 3, a pH range at which fusion characteristics of viral glycoproteins have so far remained largely unexplored. Consistent with a shifted pH optimum for fusion activation, we found wild-type LV and LVpp to display a remarkable resistance to exposure to low pH. Finally, LVpp allow the fast and quantifiable detection of neutralizing antibodies in human and animal sera and will thus facilitate the study of the humoral immune response in LV infections.


2011 ◽  
Vol 19 (1) ◽  
pp. 84-95 ◽  
Author(s):  
Jin Huk Choi ◽  
Joe Dekker ◽  
Stephen C. Schafer ◽  
Jobby John ◽  
Craig E. Whitfill ◽  
...  

ABSTRACTThe immune response to recombinant adenoviruses is the most significant impediment to their clinical use for immunization. We test the hypothesis that specific virus-antibody combinations dictate the type of immune response generated against the adenovirus and its transgene cassette under certain physiological conditions while minimizing vector-induced toxicity.In vitroandin vivoassays were used to characterize the transduction efficiency, the T and B cell responses to the encoded transgene, and the toxicity of 1 × 1011adenovirus particles mixed with different concentrations of neutralizing antibodies. Complexes formed at concentrations of 500 to 0.05 times the 50% neutralizing dose (ND50) elicited strong virus- and transgene-specific T cell responses. The 0.05-ND50formulation elicited measurable anti-transgene antibodies that were similar to those of virus alone (P= 0.07). This preparation also elicited very strong transgene-specific memory T cell responses (28.6 ± 5.2% proliferation versus 7.7 ± 1.4% for virus alone). Preexisting immunity significantly reduced all responses elicited by these formulations. Although lower concentrations (0.005 and 0.0005 ND50) of antibody did not improve cellular and humoral responses in naïve animals, they did promote strong cellular (0.005 ND50) and humoral (0.0005 ND50) responses in mice with preexisting immunity. Some virus-antibody complexes may improve the potency of adenovirus-based vaccines in naïve individuals, while others can sway the immune response in those with preexisting immunity. Additional studies with these and other virus-antibody ratios may be useful to predict and model the type of immune responses generated against a transgene in those with different levels of exposure to adenovirus.


PEDIATRICS ◽  
1986 ◽  
Vol 77 (4) ◽  
pp. 471-476
Author(s):  
Harrison C. Stetler ◽  
Walter A. Orenstein ◽  
Roger H. Bernier ◽  
Kenneth L. Herrmann ◽  
Barry Sirotkin ◽  
...  

Two hundred fifty-four infants who had received measles vaccine at <10 months of age were revaccinated at ≥15 months of age, and their immune responses were compared with 129 control infants who received their first doses of measles vaccine at ≥15 months of age. Sera were collected at the time of revaccination (study infants) or primary vaccination (control infants), 3 weeks, and 8 months later and tested for antibody by hemagglutination inhibition (HI), enzymelinked immunosorbent assay (ELISA), and cytopathic effect neutralization (CPEN). Of the 121 study infants who were initially HI negative, 116 (95.9%) made HI antibody 3 weeks postrevaccination compared with 126 (99.2%) of 127 control infants (P = 0.19). Of the 63 study infants with no initial detectable antibody by any of the three tests, 14 (22.2%) had a measles-specific IgM response 3 weeks postrevaccination compared with 37 of 50 (74.0%) randomly chosen control infants. By 8 months after revaccination, the 121 initially HI-negative study infants were significantly less likely to have detectable HI antibodies than control infants (52.1% v 97.6%) (P < .001). However, 96.7% of these 121 study infants had detectable neutralizing antibody 8 months postrevaccination, an antibody thought to correlate best with protection. This study confirms the altered immune response to revaccination in infants first vaccinated prior to 10 months of age; however, the data suggest that most of these infants were successfully primed and are probably protected after revaccination.


2020 ◽  
Author(s):  
Thibault Colombani ◽  
Loek Eggermont ◽  
Zachary Rogers ◽  
Lindsay McKay ◽  
Laura Avena ◽  
...  

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an unprecedented global health crisis, resulting in a critical need for effective vaccines that generate protective antibodies. Protein subunit vaccines represent a promising approach but often lack the immunogenicity required for strong immune stimulation. To overcome this challenge, we first demonstrate that advanced biomaterials boost effectiveness of SARS-CoV-2 protein subunit vaccines. Additionally, we report that oxygen is a powerful immunological co-adjuvant, a game-changer in the field for unlocking the full potential of vaccines. Mice immunized with oxygen-generating cryogel vaccines exhibited a robust and balanced Th1 and Th2 immune response, leading to sustained and high titer production of neutralizing antibodies against SARS-CoV-2. Our data indicate that this platform is a revolutionary technology with the potential to reinforce any vaccine.


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