scholarly journals The effects of sow viremia and maternal antibodies in porcine circovirus 2 on viral infection and weight of piglets

2014 ◽  
Vol 66 (2) ◽  
pp. 405-410 ◽  
Author(s):  
P.F. Gerber ◽  
F.M. Garrocho ◽  
Z.I.P. Lobato
Keyword(s):  
Viral Load ◽  
Neutralizing Antibodies ◽  
Maternal Antibodies ◽  
Porcine Circovirus ◽  
Serum Samples ◽  
Blood Samples ◽  
Milk Samples ◽  
Newborn Piglets ◽  
Porcine Circovirus 2 ◽  
Antibody Levels

The aim of this study was to characterize the porcine circovirus 2 (PCV2) infections in farrowing sows and to evaluate an association with piglet viremia and weight. Twenty sows and 100 newborn piglets were studied. Colostrum and serum of the sows were obtained on the day of parturition. Milk samples were collected on day 20 postpartum. Blood samples were taken and the piglets were weighed on days 1, 20, 42, 63 and 84 postpartum. Colostrum, milk and serum were evaluated for PCV2 DNA load. Serum was evaluated for neutralizing antibodies. PCV2 DNA was found in 17/20 serum samples, 14/20 colostrum samples and 11/20 milk samples. On day 1 postpartum 29% of piglets were viremic. PCV2 viral load ranged from 3.02 to 6.75 log10 copies/mL considering all sampled days. There was no correlation between sow viremia, antibody levels or PCV2 load in colostrum and piglet viremia on day 1 postpartum. The PCV2 load in colostrum and milk was associated with viremia in piglets from weaning to 84 days postpartum. Piglets' PCV2 viremia and viral load could not be associated with weight throughout this study.

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 Effect of Porcine Circovirus Type 2 (PCV2) Vaccination of the Dam on PCV2 Replication In Utero

2009 ◽  
Vol 16 (6) ◽  
pp. 830-834 ◽  
Author(s):  
D. M. Madson ◽  
A. R. Patterson ◽  
S. Ramamoorthy ◽  
N. Pal ◽  
X. J. Meng ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Specific Antigen ◽  
Porcine Circovirus Type ◽  
Porcine Circovirus Type 2 ◽  
Reproductive Failure ◽  
Porcine Circovirus ◽  
Serum Samples ◽  
Pcv2 Vaccination ◽  
Group 3

ABSTRACT The aims of this study were to determine if porcine circovirus type 2 (PCV2) vaccination of the dam is effective in preventing fetal PCV2 infection and reproductive failure. Twelve pregnant, PCV2-naïve sows were randomly divided into four groups, with three sows in each group. Group 1 sows served as noninoculated, nonvaccinated negative controls, group 2 sows were vaccinated with a commercially available PCV2 vaccine at 28 days of gestation and were not inoculated, group 3 sows were vaccinated at 28 days of gestation and inoculated with PCV2b at 56 days of gestation, and group 4 sows were inoculated with PCV2b but were not vaccinated. Serum samples from all sows were collected weekly throughout the gestation period, and sows were allowed to farrow naturally. At parturition, sow colostrum samples, presuckle serum samples, and tissues from the piglets were collected. Reproductive failure was not observed under the study conditions. PCV2 vaccination induced PCV2-specific immunoglobulin G and serum neutralizing antibodies in sows from groups 2 and 3 and prevented detectable PCV2 viremia in the dams after challenge. In group 3, PCV2 DNA was detected in colostrum samples, fetuses, and live-born pigs; however, microscopic lesions and PCV2-specific antigen were not present in any of the fetuses in this group. The results from this study indicate that vertical transmission of PCV2 can occur in PCV2-vaccinated dams.

scholarly journals Use of Quantitative Dried Blood Spots to Evaluate the Post-Vaccination Level of Neutralizing Antibodies against SARS-CoV-2

Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1125
Author(s):  
Alexandre Marchand ◽  
Ingrid Roulland ◽  
Florian Semence ◽  
Olof Beck ◽  
Magnus Ericsson
Keyword(s):  
Neutralizing Antibodies ◽  
Immune Status ◽  
Clinical Chemistry ◽  
Venous Blood ◽  
Dried Blood Spots ◽  
Post Vaccination ◽  
Blood Samples ◽  
Antibody Levels ◽  
Blood Spot ◽  
Over Time

To combat the COVID-19 pandemic, vaccines against SARS-CoV-2 are now given to protect populations worldwide. The level of neutralizing antibodies following the vaccination will evolve with time and vary between individuals. Immunoassays quantifying immunoglobulins against the viral spike (S) protein in serum/plasma have been developed, but the need for venous blood samples could limit the frequency and scale of control in populations. The use of a quantitative dried blood spot (DBS) that can be self-collected would simplify this monitoring. The objective of this study was to determine whether a quantitative DBS device (Capitainer qDBS 10 µL) could be used in combination with an Elecsys anti-SARS-CoV-2 S immunoassay from Roche to follow the development and persistence of anti-S antibodies. This objective was carried out through two clinical studies. The first study investigated 14 volunteers who received two doses of the Comirnaty (Pfizer) vaccine. The levels of anti-S antibodies and the progression over time post-vaccination were studied for three months. The level of produced antibodies varied between subjects, but a similar trend was observed. The anti-S antibodies were highly stimulated by the second dose (×100) and peaked two weeks later. The antibody levels subsequently decreased and three months later were down to 65%. DBS proved to be sufficiently sensitive for use in evaluating the immune status against SARS-CoV-2 over a prolonged time. The second cohort was composed of 200 random patients from a clinical chemistry department in Stockholm. In this cohort, we had no information on previous COVID-19 infections or vaccination. Nevertheless, 87% of the subjects had anti-S immunoglobulins over 0.8 U/mL, and the bias between plasma and DBS proved to be variable, as was also seen in the first vaccination study.

scholarly journals Antibody response between pigs of Piau and a commercial breed naturally infected with Porcine circovirus 2

2016 ◽  
Vol 68 (5) ◽  
pp. 1145-1151
Author(s):  
L.H.S. Bulos ◽  
N.F. Gonzaga ◽  
L.F.L. Souza ◽  
V.S. Assao ◽  
R.A.S. Leite ◽  
...  
Keyword(s):  
Immune Response ◽  
Viral Load ◽  
Statistical Difference ◽  
Porcine Circovirus ◽  
Humoral Immune ◽  
Serum Viral Load ◽  
Porcine Circovirus 2 ◽  
Production Stages ◽  
Fat Stores ◽  
Blood Viral Load

ABSTRACT Brazilian pig population is made up of several naturalized breeds; among them the Piau breed is known for its rusticity and large fat stores. The naturalized breeds, in comparison with commercial ones, may have an increased resistance to diseases circulating in their territory. Thus, this study aimed to verify if there are differences between the serologic profile against Porcine circovirus 2 (PCV2) of Piau pigs and that of a commercial breed from a farm naturally infected by PCV2. The serum viral load was measured by qPCR, and levels of anti-PCV2 antibodies were measured by ELISA. The results showed that the serum viral load was similar across all animals. However, Piau piglets showed higher levels of antibodies compared to commercial piglets (P= 0.05), while sows of the commercial breed showed higher levels than the Piau breed (P< 0.01). There was not a statistical difference between pigs of different production stages in the seroprevalence of PCV2 or the blood viral load. This work demonstrates that, with regard to a natural PCV2 infection, the Piau breed has a different humoral immune response compared to the response developed by the commercial pigs. The results support the importance of conservation of native breeds.

scholarly journals mRNA Vaccine-Induced Antibodies More Effective than Natural Immunity in Neutralizing SARS-CoV-2 and its High Affinity Variants

2021 ◽  
Author(s):  
Yunkai Yu ◽  
Dominic Esposito ◽  
Zhigang Kang ◽  
Jianming Lu ◽  
Alan Remaley ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
Similar Degree ◽  
Natural Immunity ◽  
Receptor Binding Domain ◽  
Blood Samples ◽  
High Affinity ◽  
Functional Assays ◽  
Highly Effective ◽  
Antibody Levels ◽  
Neutralization Ability

Abstract Several variants of SARS-CoV-2 have emerged. Those with mutations in the angiotensin-converting enzyme (ACE2) receptor binding domain (RBD) are associated with increased transmission and severity. In this study, we developed both antibody quantification and functional assays. Analyses of both COVID-19 convalescent and diagnostic cohorts strongly support the use of RBD antibody levels as an excellent surrogate to biochemical neutralization activities. Data further revealed that the samples from mRNA vaccinated individuals had a median of 17 times higher RBD antibody levels and a similar degree of increased neutralization activities against RBD-ACE2 binding than those from natural infections. Our data showed that N501Y RBD had 5-fold higher ACE2 binding than the original variant. While antisera from naturally infected subjects had substantially reduced neutralization ability against N501Y RBD, all blood samples from vaccinated individuals were highly effective in neutralizing it. Thus, our data indicates that mRNA vaccination is far more effective than natural immunity in generating highly effective neutralizing antibodies. It further suggests a potential need to maintain high RBD antibody levels to control the more infectious SARS-CoV-2 variants.

scholarly journals Viral load and antibody levels in patients with COVID-19

2021 ◽  
Vol 8 (3) ◽  
pp. 010-018
Author(s):  
Iva Christova ◽  
Iva Trifonova ◽  
Teodora Gladnishka ◽  
Elena Dragusheva ◽  
Georgi Popov ◽  
...  
Keyword(s):  
Viral Load ◽  
High Viral Load ◽  
Igg Antibodies ◽  
Rt Pcr ◽  
Serum Samples ◽  
Weekly Basis ◽  
Specific Antibody Response ◽  
Viral Loads ◽  
Antibody Levels ◽  
Kinetics Of

Relations between viral load, antibody levels and COVID-19 severity are not well studied and results from such investigations are controversial. In this study, we investigated kinetics of viral load and antibody responses to SARS-CoV-2 in 20 patients with COVID-19 and analysed the association with disease severity. The patients were followed on weekly basis within the first month after the onset and then once per month for the next 4 months. Serum samples were tested for IgA, IgM, and IgG antibodies against SARS-CoV-2 using ELISA tests. SARS-CoV-2 viral load in nasopharyngeal swabs was measured by quantitative Realtime RT-PCR. For vast majority of the patients, the viral loads were at their highest levels at presentation and then declined gradually. Despite development of specific antibody response 7-11 days after the onset of COVID-19, SARS-CoV-2 RNA was still detected in nasopharyngeal swabs of most of the patients. There was no direct link between viral load and severity of COVID-19: some of mild and some of severe cases started with a high viral load. There was a relationship between the time from the onset of the disease and the viral load: the highest viral load was in the first days. In more severe cases, there was a tendency for slower reduction in viral load and longer detection of SARS-CoV-2 virus. Levels of the specific antibodies increased earlier and to higher levels and were present for longer time in patients with more severe manifestations of COVID-19 than in those with milder disease.

Porcine Circovirus-2 Viral Load versus Lesions in Pigs: Perspectives for Post-weaning Multisystemic Wasting Syndrome

2011 ◽  
Vol 144 (4) ◽  
pp. 296-302 ◽  
Author(s):  
F.M.F. Silva ◽  
A. Silva Júnior ◽  
P.M.P. Vidigal ◽  
C.R. Oliveira ◽  
V.W. Viana ◽  
...  
Keyword(s):  
Viral Load ◽  
Porcine Circovirus ◽  
Wasting Syndrome ◽  
Porcine Circovirus 2

scholarly journals Development and Application of a Double-Antigen Sandwich Enzyme-Linked Immunosorbent Assay for Detection of Antibodies to Porcine Circovirus 2

2012 ◽  
Vol 19 (9) ◽  
pp. 1480-1486 ◽  
Author(s):  
Meng Ge ◽  
Wei Luo ◽  
Daliang Jiang ◽  
Runcheng Li ◽  
Wenwei Zhao ◽  
...  
Keyword(s):  
Capsid Protein ◽  
Immunosorbent Assay ◽  
Sandwich Elisa ◽  
Test Procedure ◽  
Porcine Circovirus ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Swine Industry ◽  
Elisa Kit ◽  
Porcine Circovirus 2

ABSTRACTA double-antigen sandwich enzyme-linked immunosorbent assay (ELISA) is described for detection of porcine circovirus 2 (PCV2) antibodies using the well-characterized recombinant PCV2 capsid protein. In a comparative test of 394 pig sera against an indirect immunofluorescence (IIF) test and a commercial ELISA kit (also based on the recombinant PCV2 capsid protein), the results showed that the diagnostic sensitivity, specificity, and accuracy of the assay were, respectively, 90.61, 94.02, and 91.62% compared with IIF and 94.38, 95.28, and 94.67% compared with the commercial ELISA kit. Assay of 12 PCV-free pigs over a 5-week period produced only PCV2-negative titers by all 3 methods. These results and the seroprofiles of 4 pig farms obtained by both the commercial ELISA kit and the double-antigen sandwich ELISA indicate that the sandwich ELISA is a reliable method for detection of antibodies to PCV2. Additionally, the method described here permits the use of undiluted test serum samples simultaneously loaded with horseradish peroxidase (HRP)-conjugated antigen into the test well, and the complete test procedure can be performed in less than 90 min. This double-antigen sandwich ELISA should be a useful tool to aid swine industry professionals in deciding the intervention strategies for the control of PCV2-associated diseases.

scholarly journals Serological survey of porcine circovirus 2 antibodies in Northeastern Brazil by immunoperoxidase monolayer assay

2020 ◽  
Vol 41 (1) ◽  
pp. 345
Author(s):  
Priscila Rocha Duque ◽  
Antonio Samuel Alves da Silva ◽  
Marconi Rego Barros Júnior ◽  
Andreza Maria Tenório Sergio ◽  
Clara Nilce Barbosa
Keyword(s):  
Rio Grande ◽  
Northeastern Brazil ◽  
Porcine Circovirus ◽  
Serological Survey ◽  
Serum Samples ◽  
Specific Antibodies ◽  
Significant Difference ◽  
Porcine Circovirus 2 ◽  
Commercial Farms ◽  
Antibody Titers

Porcine circovirus 2 (PCV2) specific antibodies were evaluated in pigs at 15 to 25 weeks of age by immunoperoxidase monolayer assay. Serum samples (n = 575) were obtained from 16 commercial farms located in six states of northeastern Brazil, including two in Ceará (n = 85), three in Rio Grande do Norte (n = 92), two in Paraíba (n = 49), three in Pernambuco (n = 107), two in Alagoas (n = 39), and four in Bahia (n = 203). Out of the 575 evaluated sera, 470 (81.74%) were reagents with antibody titers ranging from 20 to 5,120. All farms presented reactive animals. There was a statistically significant difference in reactivity proportions between the states of Bahia and Ceará (p < 0.05) and between Bahia and Rio Grande do Norte (p < 0.05). This study provides the first serological investigation for PCV2 in pigs from commercial farms in Northeastern Brazil.

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