scholarly journals Antibody level of New Zealand children immunized with the triple vaccine DTP (diphtheria-tetanus-pertussis)

1988 ◽  
Vol 101 (2) ◽  
pp. 405-410 ◽  
Author(s):  
R. C. H Lau
Keyword(s):  
New Zealand ◽  
Immunosorbent Assay ◽  
Antibody Level ◽  
Herd Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Immunization Strategy ◽  
The Mean ◽  
Antibody Levels

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.

scholarly journals Enzyme-Linked Immunosorbent Assay for Measurement of Cytomegalovirus Glycoprotein B Antibody in Serum

2010 ◽  
Vol 17 (5) ◽  
pp. 836-839 ◽  
Author(s):  
Daniel J. Hackett ◽  
Changpin Zhang ◽  
Carla Stefanescu ◽  
Robert F. Pass
Keyword(s):  
Immunosorbent Assay ◽  
Geometric Mean ◽  
Mean Value ◽  
Glycoprotein B ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Negative Results ◽  
Wide Range ◽  
The Mean ◽  
Antibody Levels

ABSTRACT Measurement of antibody to cytomegalovirus (CMV) glycoprotein B (gB) is valuable in the assessment of the antibody response to infection and to gB-containing vaccines. For this purpose, an enzyme-linked immunosorbent assay (ELISA) with a recombinant CMV gB molecule as the antigen was evaluated. Sera from 168 anti-CMV IgG-positive and 100 seronegative subjects were used to evaluate the anti-gB antibody assay. A cutoff optical density (OD) that would distinguish gB antibody-positive from -negative sera was established. Titers of antibody to gB determined by endpoint dilution were compared with those calculated using regression analysis. The run-to-run and interoperator reproducibilities of results were measured. The mean OD + 5 standard deviations from 50 anti-CMV IgG antibody-negative sera (0.2472) was used as the cutoff between anti-gB antibody-positive and -negative results. All sera from 100 anti-CMV IgG-seronegative subjects were negative for antibody to gB. All but 1 of 168 sera from seropositive subjects were positive for antibody to gB. Observed antibody levels based on titration to the endpoint were very similar to results calculated using linear regression. The run-to-run consistency of endpoints was excellent, with 38 runs from one operator and 48 runs from another all giving results within 1 dilution of the mean value for each of three anti-CMV IgG antibody-positive serum pools. The geometric mean titer of antibody to gB for 99 sera from seropositive blood donors was 1/10,937. This ELISA gives accurate and reproducible results for the relative quantity of anti-CMV gB IgG in serum over a wide range of antibody levels.

scholarly journals Single-Dilution Enzyme-Linked Immunosorbent Assay for Quantification of Antigen-Specific Salmonid Antibody

2000 ◽  
Vol 12 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Stewart W. Alcorn ◽  
Ronald J. Pascho
Keyword(s):  
Immunosorbent Assay ◽  
Sockeye Salmon ◽  
High Titer ◽  
Repeated Measurements ◽  
Enzyme Linked Immunosorbent Assay ◽  
Antibody Activity ◽  
Standard Curve ◽  
Test Fish ◽  
The Mean ◽  
Antibody Levels

An enzyme-linked immunosorbent assay (ELISA) was developed on the basis of testing a single dilution of serum to quantify the level of antibody to the p57 protein of Renibacterium salmoninarum in sockeye salmon ( Oncorhynchus nerka). The levels of antibody were interpolated from a standard curve constructed by relating the optical densities (OD) produced by several dilutions of a high-titer rainbow trout ( O. mykiss) antiserum to the p57 protein. The ELISA OD values produced by as many as 36 test sera on each microplate were compared with the standard curve to calculate the antigen-specific antibody activity. Repeated measurements of 36 samples on 3 microplates on each of 6 assay dates indicated that the mean intraassay coefficient of variation (CV) was 6.68% (range, 0–23%) and the mean interassay CV was 8.29% (range, 4–16%). The antibody levels determined for the serum sample from 24 sockeye salmon vaccinated with a recombinant p57 protein generally were correlated with the levels determined by endpoint titration ( r2 = 0.936) and with results from another ELISA that was based on extrapolation of antibody levels from a standard curve ( r2 = 0.956). The single-dilution antibody ELISA described here increases the number of samples that can be tested on each microplate compared with immunoassays based on analysis of several dilutions of each test serum. It includes controls for interassay standardization and can be used to test fish weighing <3 g.

scholarly journals Anti-S. typhi Vi IgG levels in children with and without typhoid vaccinations

2014 ◽  
Vol 54 (5) ◽  
pp. 284
Author(s):  
Sriandayani Sriandayani ◽  
Tonny H. Rampengan ◽  
Hesti Lestari ◽  
Novie Rampengan
Keyword(s):  
Typhoid Fever ◽  
Enzyme Linked Immunosorbent Assay ◽  
Control Group ◽  
Igg Antibody ◽  
Protective Antibody ◽  
Significant Difference ◽  
Antibody Titers ◽  
The Mean ◽  
And Gender ◽  
Antibody Levels

Background Typhoid fever is endemic to Indonesia, with an annual incidence of 13/10,000 people. Vaccination has been shown to be an effective method to prevent typhoid fever. Of several vaccine types, the polysaccharide Vi vaccine is the most commonly used typhoid vaccine in developing countries. Results of previous studies remain inconclusive on the necessity of revaccination every 3 years.Objective To compare the mean serum anrioody titers of anti-S. typhi Vi IgG and the proportion of children with protective antibody levels between children with and without typhoid Vi vaccination.Methods We conducted a cross-secrional study at Tuminring District, 11anado from June to September 2012. Data was analyzed using independent T-test and Fisher's test. Serum anti-S. typhi Vi IgG levels were measured by enzyme-linked immunosorbent assay (ELISA) method.Results Seventy-six subjects were divided into two groups: 38 children who had received the typhoid Vi vaccination more than 3 years prior to this study and 38 children who never had typhoid vaccinations as a control group. No statistically significant difference in age and gender was found between the two groups. The mean serum anti-Vi IgG level was 0.55 ug/mL (SD 0.58; 95%CI 0.36 to 0.74) in the vaccinated group, significantly higher than that of the control group [0.31 ug/mL (SD 0.12); 950/£1 0.17 to 0.44; P􀂥0.0381. The proportion of children with protective antiNi antioody level was higher in the vaccinated group (23.7%) than in the control group  (10.5%), howevet; this difference was not statistically significant (P=0.128).Conclusion The mean serum anti-S. typhi Vi IgG antibody level in children who had been vaccinated more than 3 years prior to the study is higher than in children who had never received typhoid vaccinations. Nevertheless, the mean antibody titers are generally non-protective in ooth groups. Also, the proportion of children with protective antibody levels is not significantly different between the two groups.

scholarly journals Enzyme-linked immunosorbent assay determination of specific rubella antibody levels in micrograms of immunoglobulin G per milliliter of serum in clinical samples

1978 ◽  
Vol 8 (4) ◽  
pp. 419-423
Author(s):  
P O Leinikki ◽  
I Shekarchi ◽  
P Dorsett ◽  
J L Sever
Keyword(s):  
Immunosorbent Assay ◽  
Immunoglobulin G ◽  
Solid Phase ◽  
Laboratory Diagnosis ◽  
Clinical Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibody ◽  
Standard Curve ◽  
Antibody Levels

A "microgram assay" is described in which solid-phase enzyme-linked immunosorbent assay is used for the determination of specific rubella immunoglobulin G (IgG) antibody levels in micrograms per milliliter of serum. The quantitation was based on a standard curve obtained by using a reference serum, for which the specific IgG content was assayed by immunochemical purification. IgG was first purified and specific rubella antibodies were separated by an immunoadsorbent prepared by linking rubella virus antigens to Sepharose 4B. By using IgG-specific conjugate, the levels of specific rubella IgG antibodies could then be determined from clinical samples. Seronegative samples showed antibody levels less than 1 microgram/ml, whereas levels up to several hundred micrograms per milliliter were detected in some postinfection sera. The correlation between microgram antibody levels and hemagglutination inhibition titers was linear. The method offers a simple and sensitive antibody assay which could be used both for the laboratory diagnosis of acute rubella and for the evaluation of immunity.

scholarly journals Seroprevalence of diphtheria toxoid IgG antibodies in the Malaysian population

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ahmad Faudzi Yusoff ◽  
Zatil Zahidah Mohd Sharani ◽  
Chee Cheong Kee ◽  
Nuur Hafizah Md Iderus ◽  
Ahmed Syahmi Syafiq Md Zamri ◽  
...  
Keyword(s):  
Antibody Level ◽  
Immunization Coverage ◽  
Booster Vaccination ◽  
Diphtheria Toxoid ◽  
Childhood Vaccination ◽  
Enzyme Linked Immunosorbent Assay ◽  
Childhood Immunization ◽  
Igg Antibody ◽  
Malaysian Population ◽  
Antibody Levels

Abstract Background Despite high childhood immunization coverage, sporadic cases of diphtheria have been reported in Malaysia in recent years. This study aims to evaluate the seroprevalence of diphtheria among the Malaysian population. Methods A total of 3317 respondents age 2 years old to 60 years old were recruited in this study from August to November 2017. Enzyme-linked immunosorbent assay (ELISA) was used to measure the level of IgG antibody against the toxoid of C. diphtheriae in the blood samples of respondents. We classified respondent antibody levels based on WHO definition, as protective (≥0.1 IU/mL) and susceptible (< 0.1 IU/mL) to C. diphtheriae infection. Results Among the 3317 respondents, 57% were susceptible (38.1% of children and 65.4% of adults) and 43% (61.9% of children and 34.6% of adults) had protective antibody levels against diphtheria. The mean antibody level peaked among individuals aged 1–2 years old (0.59 IU/mL) and 6–7 years old (0.64 IU/mL) but generally decreased with age, falling below 0.1 IU/mL at around 4–6 years old and after age 20 years old. There was a significant association between age [Children: χ2 = 43.22(df = 2),p < 0.001)], gender [Adults: χ2 = 5.58(df = 1),p = 0.018] and ethnicity [Adults: χ2 = 21.49(df = 5),p = 0.001] with diphtheria toxoid IgG antibody level. Conclusions About 57% of the Malaysian population have inadequate immunity against diphtheria infection. This is apparently due to waning immunity following childhood vaccination without repeated booster vaccination in adults. Children at age 5–6 years old are particularly vulnerable to diphtheria infection. The booster vaccination dose normally given at 7 years should be given earlier, and an additional booster dose is recommended for high-risk adults.

scholarly journals SARS-CoV-2 IgG Antibodies Seroprevalence and Sera Neutralizing Activity in MEXICO: A National Cross-Sectional Study during 2020

2021 ◽  
Vol 9 (4) ◽  
pp. 850
Author(s):  
José Esteban Muñoz-Medina ◽  
Concepción Grajales-Muñiz ◽  
Angel Gustavo Salas-Lais ◽  
Larissa Fernandes-Matano ◽  
Constantino López-Macías ◽  
...  
Keyword(s):  
Immunosorbent Assay ◽  
Neutralizing Antibodies ◽  
Herd Immunity ◽  
Cross Sectional Study ◽  
Molecular Techniques ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cross Sectional ◽  
Neutralizing Activity

Until recently, the incidence of COVID-19 was primarily estimated using molecular diagnostic methods. However, the number of cases is vastly underreported using these methods. Seroprevalence studies estimate cumulative infection incidences and allow monitoring of transmission dynamics, and the presence of neutralizing antibodies in the population. In February 2020, the Mexican Social Security Institute began conducting anonymous unrelated sampling of residual sera from specimens across the country, excluding patients with fever within the previous two weeks and/or patients with an acute respiratory infection. Sampling was carried out weekly and began 17 days before Mexico’s first officially confirmed case. The 24,273 sera obtained were analyzed by chemiluminescent-linked immunosorbent assay (CLIA) IgG S1/S2 and, later, positive cases using this technique were also analyzed to determine the rate of neutralization using the enzyme-linked immunosorbent assay (ELISA). We identified 40 CLIA IgG positive cases before the first official report of SARS-CoV-2 infection in Mexico. The national seroprevalence was 3.5% in February and 33.5% in December. Neutralizing activity among IgG positives patients during overall study period was 86.1%. The extent of the SARS-CoV-2 infection in Mexico is 21 times higher than that reported by molecular techniques. Although the general population is still far from achieving herd immunity, epidemiological indicators should be re-estimated based on serological studies of this type.

SENSITIVE AND SPECIFIC ENZYME-LINKED IMMUNOSORBENT ASSAY FOR UROKINASE-TYPE PLASMINOGEN ACTIVATOR IN HUMAN PLASMA

1987 ◽  
Author(s):  
J Grøndahl-HANSEN ◽  
N Agerlin ◽  
L S Nielsen ◽  
K Danø
Keyword(s):  
Plasminogen Activator ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mean Values ◽  
Amino Terminal ◽  
Type Plasminogen Activator ◽  
Healthy Donors ◽  
Urokinase Type Plasminogen Activator ◽  
The Mean

An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of human urokinase-type plasminogen activator (u-PA) in plasma and serum. Microtiter plates were coated with a monoclonal antibody and incubated with standard or sample. Bound u-PA was quantitated with polyclonal antibodies conjugated with biotin, followed by avidin-peroxidase. The assay was 10-fold as sensitive as other previously reported ELISAs, the detection limit being approximately 1 pg of u-PA in a volume of 100 μl with a linear dose-response up to 15 pg of u-PA. The assay detected active u-PA and its inactive proenzyme form equally well and the recovery of both forms was higher than 90% in plasma. A variety of structurally related proteins, including t-PA, were tested, but no reaction with proteins other than u-PA and its amino-terminal degradation product were observed. The intra-assay and inter-assay coefficients of variation for determination of u-PA in plasma were 7.6% and 8.4%, respectively. The assay was equally applicable to serum. The values obtained with plasma and serum were similar, and the results were not affected by small variations in the preparation of the samples. The ELISA was used to measure the concentration of u-PA in plasma from 34 healthy donors. The mean values for u-PA in plasma from healthy donors was 1.1 ng/ml ± 0.3 ng/ml (SD) (range 0.6 - 1.5 ng/ml). No significant differences were found between men and women and no correlation between u-PA concentration and age could be demonstrated.The mean u-PA concentration in plasma from healthy donors obtained in this study is substantially lower than that reported by others. This might be due to different methods of determination of the protein content of the standard preparations or to differences in the specificity of the assays.

Comparison of an enzyme-linked immunosorbent assay for quantitation of rotavirus antibodies with complement fixation in an epidemiological survey

1978 ◽  
Vol 8 (3) ◽  
pp. 268-276
Author(s):  
L H Ghose ◽  
R D Schnagl ◽  
I H Holmes
Keyword(s):  
Immunosorbent Assay ◽  
Complement Fixation ◽  
Age Groups ◽  
Enzyme Reaction ◽  
Epidemiological Survey ◽  
Enzyme Linked Immunosorbent Assay ◽  
Marker Enzyme ◽  
Aminosalicylic Acid ◽  
Antibody Titers ◽  
Antibody Levels

The development of a micro-scale enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase as the marker enzyme for the detection and measurement of human rotavirus antibodies is described. A semipurified preparation of the serologically related simian agent, SA-11 virus, was used as the antigen. Test sera were reacted with antigen-sensitized wells in disposable poly-vinyl microplates. Any attached antibody was detected by the addition of peroxidase-labeled anti-species immunoglobulin (conjugate) followed by assay of the enzyme reaction with its substrate, hydrogen peroxide plus 5-aminosalicylic acid. This micro-ELISA was compared with complement fixation in a seroepidemiological study of the age prevalence of rotavirus antibody in Aboriginal and European populations living in the same outback area in Australia. The ELISA (results read with the naked eye) proved to be approximately 16 times more sensitive than complement fixation. Of Aborigines, 71% had rotavirus complement-fixing antibody, as compared to 45% of Europeans. By ELISA 100% of both populations had rotavirus antibodies. Mean antibody titers in the different age groups were higher in Aborigines than in Europeans. Antibody levels rose steeply throughout the first 20 years of life, remained high during the next 20 years, then increased again at least up to the age of 60 years. The micro-ELISA was practical, simple to perform, and more suitable than complement fixation for large seroepidemiological rotavirus studies. It also has potential for serodiagnosis of the disease, both in the laboratory and in the field.

scholarly journals Development and Validation of 13-plex Luminex-Based Assay for Measuring Human Serum Antibodies to Streptococcus pneumoniae Capsular Polysaccharides

mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. e00128-18 ◽  
Author(s):  
Danka Pavliakova ◽  
Peter C. Giardina ◽  
Soraya Moghazeh ◽  
Shite Sebastian ◽  
Maya Koster ◽  
...  
Keyword(s):  
Human Serum ◽  
Lower Limit ◽  
Immunosorbent Assay ◽  
Enzyme Linked Immunosorbent Assay ◽  
Igg Antibodies ◽  
Igg Antibody ◽  
Correlate Of Protection ◽  
Immune Correlate ◽  
Relative Standard ◽  
Limit Of Quantitation

ABSTRACT A Luminex-based direct immunoassay (dLIA) platform has been developed to replace the standardized pneumococcal enzyme-linked immunosorbent assay platform. The multiplex dLIA simultaneously measures the concentration of serum immunoglobulin G (IgG) antibodies specific for pneumococcal capsular polysaccharide (PnPS) serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F. The assay uses poly-l-lysine (PLL)-conjugated PnPS, chemically coupled to spectrally distinct Luminex microspheres. Assay validation experiments were performed using residual human serum samples obtained from 13-valent pneumococcal conjugate vaccine (13vPnC) clinical studies. Assay results are expressed as IgG antibody concentrations in micrograms per milliliter using the international reference serum, 007sp. The lower limit of quantitation (LLOQ) for all serotypes covered in the 13-plex dLIA fell within the range of 0.002 to 0.038 µg/ml serum IgG. The difference between the lower limit and upper limit of the assay range was >500-fold for all serotypes, and assay variability was <20% relative standard deviation (RSD) for all serotypes. IgG antibody measurements were shown to be serotype-specific (some cross-reactivity was observed only between the structurally related serotypes 6A and 6B as well as 19A and 19F), and no interference was observed between the serotypes when the assay was performed in the 13-plex format compared to the singleplex assays. The 13-plex dLIA platform developed by Pfizer Inc. generates up to 143 test results in a single 96-well plate and is a suitable replacement of the enzyme-linked immunosorbent assay (ELISA) platform for evaluating vaccine clinical trials. IMPORTANCE The pneumococcal enzyme-linked immunosorbent assay (ELISA) measures IgG antibodies in human serum, and it is an important assay that supports licensure of pneumococcal vaccines. The immune correlate of protection, 0.35 µg/ml of IgG antibodies, was determined by the ELISA method. Pfizer has developed a new Luminex-based assay platform to replace the ELISA. These papers describe the important work of (i) validating the Luminex-based assay and (ii) bridging the immune correlate of protection (0.35 µg/ml IgG) to equivalent values reported by the Luminex platform.

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