Test For Detection Of Antibodies Research Articles

Seroprevalence of leptospirosis among captive Asian elephants in Kerala, India - a short communication

Leptospirosis is an infectious disease of zoonotic significance, caused by distinct members of the genus Leptospira, with a broad spectrum of hosts, including domestic and wild animals. The present paper reports the seroprevalence of leptospirosis among captive Asian elephants in Kerala. Whole blood samples were collected from fifty, apparently healthy captive elephants from different districts of Kerala state. The serum was separated from the whole blood and subjected to the Microscopic Agglutination Test (MAT) for detection of antibodies to different serovars of Leptospira. The test was carried out using actively grown cultures of twelve common leptospiral serovars. Out of the total of fifty serum samples screened by MAT, 19 samples (38 per cent) showed a positive reaction with antibody titres in a 1:200 dilution. The prevalent serovars were Pomona, Icterohaemorrhagiae, Hebdomadis, Grippotyphosa and Canicola, and the highest prevalence was noticed for the serovar Pomona. The positive results indicated the presence of infection or the previous exposure of captive elephants to leptospiral antigens. The high rate of prevalence of leptospiral antibodies in captive elephants warrants the monitoring of these animals for clinical disease and adopting the necessary control strategies for preventing this re-emerging zoonotic disease.

Positive direct antiglobulin tests in cancer patients on immune checkpoint inhibitors: A case series from India.

Tumour cells activate immune checkpoints such as programmed death receptor-1 (PD-1) and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) signalling pathways to inhibit T lymphocyte activation and thus escape from immune surveillance. Immune checkpoint inhibitors (ICPis) reactivate T lymphocytes to recognize cancer cells by blocking CTLA-4 or PD-1. Autoimmune haemolytic anaemia is a rare, but often severe, complication of ICPis. Therefore, we performed a retrospective clinical case review, including serologic, haematology, and biochemistry laboratory results, of three patients who developed autoantibodies to erythrocytes following treatment with pembrolizumab, an anti-PD-1 inhibitor. Serologic testing of blood samples from these patients showed their red cells were positive for direct antiglobulin test (DAT+for IgG in two cases and IgG with C3d in one case). Antibody detection test was negative. No patient had clinical and laboratory features of haemolysis. There were no additional immune-related adverse events. IgG antibodies coating red cells were neither IgG1 nor IgG3 in class and elution was found negative in all. In conclusion, immunohaematology laboratories should be aware of the possibility of erythroid autoantibodies and their nature in cancer patients receiving ICPis. The result of a positive DAT should be interpreted carefully in these patients to exclude other possible causes of anaemia.

The importance of prevalence and pre-test probability on the microbiological diagnosis of SARS-CoV-2: the case of Spain in 2020.

The aim of this work was to estimate the conditioned probability for the diagnosis of SARS-CoV-2 infection with reverse transcription polymerase chain reaction (RT-PCR), viral antigen rapid diagnostic tests (Ag-RDT), and antibody detection tests depending on the prevalence in the specific healthcare settings in Spain in 2020, and on the pre-test probability (PTP) according to the clinical situation, age and unknown or close contacts of the patient. Performance parameters of tests were obtained from literature. Prevalence data and PTP were obtained from Spanish sources and a survey, respectively. The post-test probability is the positive predictive value (PPV) when test is positive. For negative result, we also calculated the probability of having the infection (false negatives). For both RT-PCR and viral Ag-RDT, the lowest PPV values were for the population screenings. This strategy proved to be useful in ruling out infection but generates a high number of false positives. At individual level, both tools provided high PPV (≥ 97%) when the PTP values are over 35%. In seroprevalence studies, though the specificity of IgG alone tests is high, under low seroprevalence, false positives cannot be avoided. Total antibodies tests are useful for diagnosis of COVID-19 in those doubtful cases with RT-PCR or Ag-RDT tests being repeatedly negative. The interpretating of results depends not only on the accuracy of the test, but also on the prevalence of the infection in different settings, and the PTP associated to the patient before performing the test.

Clinical performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of hepatitis C virus antibodies

BackgroundHepatitis C virus (HCV) infection screening and diagnosis are critical to control the hepatitis C epidemic. Testing for anti-HCV antibodies (Ab) in blood samples is the first step to screen people who have been infected with the virus. ObjectivesTo evaluate the performance of the MAGLUMI Anti-HCV (CLIA) Test for detection of HCV antibodies. Study designTo assess the diagnostic specificity, serum samples from 5053 unselected donors and 205 blood specimens from hospitalized patients were collected. To evaluate the diagnostic sensitivity, 400 positive HCV Ab samples were collected and 30 seroconversion panels were tested. All samples that met the test criteria were tested with the MAGLUMI Anti-HCV (CLIA) Test according to manufacturer’s instruction. Results of the MAGLUMI Anti-HCV (CLIA) Test were compared with the Abbott ARCHITECT anti-HCV reference test. ResultsThe specificity of the MAGLUMI Anti-HCV (CLIA) Test was 99.75% and 100.00% in blood donor and hospitalized patient samples, respectively. The sensitivity of the Test in HCV Ab positive samples was 100.00%. Seroconversion sensitivity was comparable between the MAGLUMI Anti-HCV (CLIA) Test and the reference assay. ConclusionsThe performance of the MAGLUMI Anti-HCV (CLIA) Test makes it suited for HCV infection diagnosis.

Diagnostic Accuracy of Rapid Antibody Detection Test for Scrub Typhus

Diagnostic Accuracy of Rapid Antibody Detection Test for Scrub Typhus

Characterization of antigenic preparations for anti-HCV screening tests: Issue of test performance

Screening for anti-HCV antibodies is often subject to contradiction between different laboratories due to the use of tests from different manufacturers. In this study, we have proceeded to the identification of the various screening tests for anti-HCV antibodies with the main concerns of the characterization of each brand according to its principle, its antigenic preparation, and its evaluation in relation to the PCR RNA HC Positive and Negative samples. Our results identified thirty-two anti-HCV tests, of which 90.7% of the anti-HCV antibody detection tests had the following principles: simple liquid phase immunochromatography and solid support, the other tests, their principles were based either on the immunobolt (3.125%) or on sandwich immunochromatography (6.25%). 22 tests (68.75%) had no specification of the antigen preparation 9 tests mentioned (28.125%) recombinant proteins and only 1 test (3.125%) Recombinant proteins + synthetic peptides The correspondence was the antigen preparation, and its composition was such that 12 tests of recombinant protein preparations consisted of 8 tests contained the core, NS3, NS4 and NS5 proteins; 1 tests nucleocapsid and non-structural proteins. The evaluation of the anti-HCV tests presents on the Lubumbashi market, it turns out that the antigenic preparation tests: Core, NS3, NS4, NS5, meet the description of third-generation anti-HCV tests, because they consist of core antigens, NS3 and NS4 antigens combined and incorporated an NS5 epitope, showed significantly improved performance in terms of sensitivity and specificity.

Robust Combination Testing: Methods and Application to COVID-19 Detection

Simple and affordable testing tools are often not accurate enough to be operationally relevant. For coronavirus disease 2019 (COVID-19) detection, rapid point-of-care tests are cheap and provide results in minutes, but they largely fail policy makers’ accuracy requirements. We propose an analytical methodology, based on robust optimization, that identifies optimal combinations of results from cheap tests for increased predictive accuracy. This methodological tool allows policy makers to credibly quantify the benefits from combination testing and thus, break the trade-off between cost and accuracy. Our methodology is robust to noisy and partially missing input data and incorporates operational constraints—relevant considerations in practice. We apply our methodology to two data sets containing individual-level results of multiple COVID-19 rapid antibody and antigen tests, respectively, to generate Pareto-dominating receiver operating characteristic curves. We find that combining only three rapid tests increases out-of-sample area under the curve by 4% (6%) compared with the best-performing individual test for antibody (antigen) detection. We also find that a policy maker who requires a specificity of at least 0.95 can improve sensitivity by 8% and 2% for antibody and antigen testing, respectively, relative to available combination testing heuristics. Our numerical analysis demonstrates that robust optimization is a powerful tool to avoid overfitting, accommodate missing data, and improve out-of-sample performance. Based on our analytical and empirical results, policy makers should consider approving and deploying a curated combination of cheap point-of-care tests in settings where “gold standard” tests are too expensive or too slow. This paper was accepted by Stefan Scholtes, healthcare management. Supplemental Material: The data files and electronic companion are available at https://doi.org/10.1287/mnsc.2023.4826 .

COMPARISON OF ANTIBODY DETECTION BY RAPID DIAGNOSTIC KIT AND ELISA TEST FOR DIAGNOSIS OF HEPATITIS C VIRUS INFECTION

Background: Hepatitis C virus (HCV) infection is a major cause of healthcare problem along with burden of health management care cost of international concern. Hepatitis C is a serious threat with long term complication. The present study is undertaken to compare rapid card test based on Immunochromatography principle with ELISA test for detection of anti HCV antibodies. In the absence of vaccine, primary prevention of Hepatitis C should be targeted to reduce transmission of virus. High risk people should be provided with education, counselling and screening. A cross-sectional study was done at Dept. of Microbiology, M.G.M.M.C, Indore Method: for one year comprising of 500 samples after getting Institutional Scientic Research and Ethics Committee approval. Rapid card and ELISA tests were performed in the samples received for detection of Anti-HCV ab. Out of 500 blood samples test Result: ed on Rapid card 22 were positive while 478 were negative. Further testing on same 500 samples with ELISA test 22 were positive and 478 were negative. Discussion: Present study ndings suggest that for screening of anti HCV antibody ELISA and Rapid card tests both can be used as diagnostic tool depending upon facilities available in the laboratory. Rapid card Conclusion: tests were found to be equally diagnostic as compared to ELISA test and hence can be recommended in screening of HCV

Timing of RhD-positive red blood cell administration is associated with D-alloimmunization in injured patients.

The D-alloimmunization rate in trauma patients does not appear to depend on the number of RhD-positive units transfused. The effect of the timing and pattern of RhD-positive transfusions has not been evaluated. RhD-negative trauma patients who were transfused with RhD-positive red blood cells (RBC) or low titer group O whole blood (collectively called RBCs) on at least two separate calendar days and who had antibody detection tests performed at least 14 days after the second RhD-positive RBC transfusion without receiving RhIg were included in the analysis. Patients whose anti-D was detected within 14 days of the index RhD-positive RBC transfusion were excluded. Patient demographics and the dates of RhD-positive RBC transfusions and results of antibody detection tests performed after the index transfusion were collected on eligible patients. There were 44/61 (72.1%) patients in whom anti-D was not detected (non-alloimmunized) and 17/61 (27.9%) in whom anti-D was detected (alloimmunized). The patients had similar demographics with trends towards higher median admission heart rates and lower median admission Glasgow Coma Scale values in the alloimmunized group. Both groups received statistically identical median quantities of RhD-positive RBCs (non-alloimmunized 5 vs. alloimmunized 4 units, p = .53), however, the alloimmunized group received all their RhD-positive RBCs over a significantly shorter period of time compared to the non-alloimmunized (median 4 vs. 15 days, respectively, p = .01). Receipt of all RhD-positive RBCs over a shorter period of time was associated with higher D-alloimmunization rates. These results need to be confirmed in larger studies.

Clinico-serological studies of Brucella infection of horses in Kano metropolis, Kano State, Nigeria

This study aimed at determining the clinico-serological status of brucellosis among horses in Kano, Kano State Nigeria. Four Local Government Areas (LGAs) were selected from Kano metropolis based on convenience and owner’s consent. A total of 328 horses, comprising ceremonial, polo and racing breeds, were used for the study. Clinical signs of brucellosis and vital parameters of the horses were documented. Blood samples were collected and the sera were subjected to modified Rose Bengal Plate Test (mRBPT) for detection of Brucella antibody. Positive samples were further screened using Serum Agglutination Test with EDTA (SAT-EDTA). The 2-Mercaptoethonol Test (2-MET) was used to determine the forms (acute or chronic) of Brucella infection. A total of 79 (24.09 %) horses had seropositivity for Brucella infection using mRBPT. The result was not statistically significant (P = 0.07). Of these 79 horses, 27 (34.18 %) were having mild infection while 12 (25.19%) others were severe. However, based on forms of brucellosis, it was inferred that out of the 39 horses that were positive for SAT-EDTA, 17 (43.59%) had acute form while 22 (56.41%) had chronic infection. From the study, it was evident that horses in Kano Metropolis had Brucella infection and this has far reaching public health implications. One of the limitations of this study was gaining free access to horse stables and insufficient funds. There is therefore, need to educate horse owners, grooms and the general public on the zoonotic implications of brucellosis. Regular surveillance should be conducted to establish the true prevalence of equine brucellosis in Nigeria.

A cerebellar degeneration-related protein 2-like cell-based assay for anti-Yo detection in patients with paraneoplastic cerebellar degeneration.

Commercially available tests for Yo antibody detection have low specificity for paraneoplastic cerebellar degeneration (PCD) because these assays use cerebellar degeneration-related protein 2 (CDR2) as the antigen, not CDR2-like (CDR2L). We aimed to test the hypothesis that use of a CDR2L cell-based assay (CBA), as an additional screening technique, would increase the accuracy of Yo-PCD diagnosis. An in-house CBA to test for anti-CDR2L antibodies was developed and used to screen sera from 48 patients with confirmed anti-Yo-associated PCD. Fifteen non-Yo PCD patients, 22 patients with ovarian cancer without neurological syndromes, 50 healthy blood donors, 10 multiple sclerosis, 15 Parkinson's disease, and five non-paraneoplastic ataxic patients were included as controls. Sera were also tested by western blot analysis using recombinant CDR2 and CDR2L proteins developed in house, by the commercially available line immunoassays from Ravo Diagnostika and Euroimmun, and by the CDR2 CBA from Euroimmun. The CDR2L CBA identified all 48 patients with Yo-PCD. No CDR2L CBA reaction was observed in any of the control sera. The western blot technique had lower sensitivity and specificity as sera from eight and six of the 48 Yo-PCD patients did not react with recombinant CDR2 or CDR2L, respectively. The CDR2L CBA is highly reliable for identification of Yo-PCD. Although our findings indicate that, currently, the combination of CDR2 and CDR2L yields the most reliable test results, it remains to be evaluated if a test for single anti-CDR2L positivity will serve as a sufficient biomarker for Yo-PCD diagnosis.

Fasciola gigantica Cathepsin L1H: High Sensitivity and Specificity of Immunochromatographic Strip Test for Antibody Detection.

Fasciolosis is a zoonotic disease caused by Fasciola gigantica or F. hepatica infections, which are frequently occurring parasites in animals and humans. The present gold-standard diagnostic technique involves finding parasite eggs through microscopy. However, this method is also restricted due to low specificity and low sensitivity. An alternative to coprological diagnosis is the immunochromatographic strip (ICS) test, which is rapid, simple, convenient, and cost-effective, with high sensitivity and high specificity. Cathepsin L1H (CathL1H) is a cysteine protease secreted by F. gigantica, which is found in high amounts in newly excysted juvenile (NEJ) and juvenile stages. Cathepsin L1H plays an important role in both the immune response to invading pathogens and in the ability of some pathogens to evade the host immune system. The present study aims to develop an ICS test and detect antibodies against CathL1H in mice and cattle serum using the recombinant F. gigantica Cathepsin L1H (rFgCathL1H) and rabbit anti-rFgCathL1H antibody. The F. gigantica-infected serum and non-infected serum of mice and cattle were tested using the ICS test. Moreover, the strip results were confirmed with an indirect enzyme-linked immunosorbent assay (indirect ELISA). The relative sensitivity, specificity, and accuracy of the ICS strip were 97.5, 99.99, and 99.00%, respectively. Therefore, these data suggest that the ICS method could be used to detect F. gigantica antibodies to highly enhance throughput, reduce costs, and determine the best alternative on-site method.

Reliability of antibody tests for COVID-19 diagnosis

Objective: The reverse transcription–polymerase chain reaction test (RT-PCR) is the gold standard for the diagnosis of coronavirus
 disease 2019 (COVID-19), and antibody tests are useful as supplemental tools for diagnosis, for measuring the population’s immunity
 levels, and for checking infection in asymptomatic contacts. This study aimed to evaluate the reliability of five commercial antibody
 detection test kits.
 Materials and Methods: The reliability of the Colloidal Gold COVID-19 IgG/IgM Rapid Test Kit, Antibody Rapid Test Hotgen,
 Beijing Hotgen Biotech Co., Ltd., China), Abbott Chemiluminescent Microparticle Immunoassay (Illinois, USA), Roche
 Electrochemiluminescence Immunoassay (Roche Diagnostics, Switzerland), Siemens Chemiluminescence (Munich, Germany), and
 Euroimmun ELISA (Lübeck, Germany) for COVID-19 diagnosis was studied. The antibody-negative group included 50 sera from
 2018, and the antibody-positive group included 98 patients with positive RT-PCR results from whom blood samples had been collected
 3–9 weeks after hospital discharge. Statistical analysis was performed using SPSS version 23.0 (IBM Corporation, Armonk, NY, USA).
 The antibody tests’ validity and intra-assay reproducibility were examined, and the Cohen’s kappa coefficients were obtained. The
 disease prevalence was pegged at 10%.
 Results: The antibody tests’ sensitivity (69.12–72.46%) and positive predictive values (42.44–100.0%) were low, and their specificity
 (89.58–100%) and negative predictive values (96.31–97.03%) were high. Their accuracy rates varied from 87.54% to 97.25%, and their
 intra-assay coefficients of variation varied from 1% to 10%.
 Conclusion: The agreement between the results of the antibody detection test kits was higher when the kits were classified according to
 the targeted antigens. The time of blood sample collection, targeted antigens, and antibody types affected the results. Serological tests
 were found to be useful, and the commercial kits were found to be largely reliable, although, some parameters need to be improved.

Mobile SARS‑CoV‑2 screening facilities for rapid deployment and university-based diagnostic laboratory.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has created a public crisis. Many medical and public institutions and businesses went into isolation in response to the pandemic. Because SARS-CoV-2 can spread irrespective of a patient's course of disease, these institutions' continued operation or reopening based on the assessment and control of virus spread can be supported by targeted population screening. For this purpose, virus testing in the form of polymerase chain reaction (PCR) analysis and antibody detection in blood can be central. Mobile SARS-CoV-2 screening facilities with a built-in biosafety level (BSL)-2 laboratory were set up to allow the testing offer to be brought close to the subject group's workplace. University staff members, their expertise, and already available equipment were used to implement and operate the screening facilities and a certified diagnostic laboratory. This operation also included specimen collection, transport, PCR and antibody analysis, and informing subjects as well as public health departments. Screening facilities were established at different locations such as educational institutions, nursing homes, and companies providing critical supply chains for health care. Less than 4 weeks after the first imposed lockdown in Germany, a first mobile testing station was established featuring a build-in laboratory with two similar stations commencing operation until June 2020. During the 15-month project period, approximately 33,000 PCR tests and close to 7000 antibody detection tests were collected and analyzed. The presented approach describes the required procedures that enabled the screening facilities and laboratories to collect and process several hundred specimens each day under difficult conditions. This report can assist others in establishing similar setups for pandemic scenarios.

A Rare Case of Bm (Bweak) Phenotype Detected in a Healthy Blood Donor from Eastern India

A 52-year-old male repeats voluntary blood donor donated at our blood center for the first time. Historical blood group was O, Rh (D) positive. Initial blood grouping was done on the fully automated immunohematology analyzer using column agglutination technique (CAT). Discrepant results (forward as group O and reverse as group B) were observed while performing the ABO blood grouping by CAT. Repeat testing by conventional tube technique showed the same discrepancy. Antibody detection test and direct antiglobulin test results were negative. After adsorption-elution, the eluate reacted only with group B red cells. Saliva testing for secretor status shows the presence of B and H substances. Finally, it was classified as a case of Bm (now called Bweak) phenotype. As a precautionary measure, the donor was recalled and a special blood group card was issued with a clear mention of his respective donor and recipient status. This case showed the importance of ABO subgroup determination that can help blood centers to establish defined transfusion protocol and prepare an elaborate rare blood donor registry.

Development of an immunochromatographic strip test for rapid detection of a potent neutralizing anti-interferon gamma antibody in adult-onset immunodeficiency.

Adult-onset immunodeficiency (AOID) is associated with the presence of anti-interferon gamma autoantibodies (anti-IFN-γ autoAbs), which neutralizes IFN-γ signaling and leads to susceptibility to intracellular opportunistic infections. However, measuring neutralizing autoAbs is not practical for general clinical laboratories. This study aims to develop a competitive immunochromatographic (IC) strip test for detecting autoAbs that recognize the same epitope as a potent neutralizing antibody. The competitive IC strip test detecting autoAbs that recognize the same epitope as mouse anti-IFN-γ monoclonal antibody, clone B27 (B27 mAb) was fabricated and used to determine B27 epitope recognizing autoAb (B27 AAb) in AOID plasma. The competitive ELISA was used as a comparative method. AR patients. The efficacy of the IC strip test was compared with competitive ELISA and found a percent positive agreement of 91.30%, a percent negative agreement of 79.31%, and a percent overall agreement of 84.62%. The results from the competitive IC strip test were consistent with those from competitive ELISA, indicating that the generated IC strip could detect B27 AAb in AOID plasma.

Type and Screen Method versus Antihuman Globulin Crossmatch in Pretransfusion Testing: A Cross-sectional Study

Introduction: Blood transfusion remains the primary modality of treatment for many serious and common diseases. According to the International Society of Blood Transfusion (ISBT), there are about 349 blood group antigens, out of which only about 25-28 antigens are known to cause acute or delayed type of haemolytic transfusion reactions which could be prevented by Pretransfusion Testing (PTT). Regulated pretransfusion tests include ABO blood grouping, Rh typing, antibody detection, antibody identification and compatibility testing. The purpose of compatibility tests is to demonstrate invitro red cell antigen-antibody reaction. The Antihuman Globulin (AHG) crossmatch testing can assure ABO compatibility between donor and patient blood as well as detect most clinically significant antibodies. Type and Screen (T&S) is a procedure carried out as part of PTT in which the recipient’s blood sample is tested for ABO group, RhD T&S for unexpected antibodies. Aim: To compare T&S method of PTT with AHG crossmatch. Materials and Methods: This cross-sectional study was conducted in the department of Transfusion medicine at Government Royapettah Hospital, Chennai and The Tamil Nadu Dr. MGR Medical University, Chennai, Tamil Nadu, India from June 2012 to December 2013. T&S was performed on 1,040 recipients’ (510 males and 530 females) samples. All these samples were subjected to AHG crossmatch with ABO group and RhD type matched donor samples to assess the compatibility between donor and recipient by using column agglutination technology. Statistical analysis was carried out using Statistical Package for the Social Sciences (SPSS) version 11.0. Results: The prevalence of unexpected antibodies in the recipient population was 1.06%. Among the 1,040 recipients’ blood samples, 11 samples were found to have unexpected antibodies. Out of these 11 samples, 10 showed exact antibodies and the remaining one sample with negative antibody screening was found to be incompatible with AHG crossmatch. The sensitivity and specificity of T&S method in comparison to AHG crossmatch was 87.50% and 99.71%, respectively. Conclusion: The sensitivity and specificity of T&S is as acceptable as AHG crossmatch. However, in view of one sample with false negative antibody screening in the study population, it is imperative to know the phenotyping of Red Blood Cells (RBC) antigens of the native population before getting away with AHG crossmatch.

An update on lateral flow immunoassay for the rapid detection of SARS-CoV-2 antibodies.

Over the last three years, after the outbreak of the COVID-19 pandemic, an unprecedented number of novel diagnostic tests have been developed. Assays to evaluate the immune response to SARS-CoV-2 have been widely considered as part of the control strategy. The lateral flow immunoassay (LFIA), to detect both IgM and IgG against SARS-CoV-2, has been widely studied as a point-of-care (POC) test. Compared to laboratory tests, LFIAs are faster, cheaper and user-friendly, thus available also in areas with low economic resources. Soon after the onset of the pandemic, numerous kits for rapid antibody detection were put on the market with an emergency use authorization. However, since then, scientists have tried to better define the accuracy of these tests and their usefulness in different contexts. In fact, while during the first phase of the pandemic LFIAs for antibody detection were auxiliary to molecular tests for the diagnosis of COVID-19, successively these tests became a tool of seroprevalence surveillance to address infection control policies. When in 2021 a massive vaccination campaign was implemented worldwide, the interest in LFIA reemerged due to the need to establish the extent and the longevity of immunization in the vaccinated population and to establish priorities to guide health policies in low-income countries with limited access to vaccines. Here, we summarize the accuracy, the advantages and limits of LFIAs as POC tests for antibody detection, highlighting the efforts that have been made to improve this technology over the last few years.

Evaluation of Two Adjuvant Formulations for an Inactivated Yellow Fever 17DD Vaccine Candidate in Mice.

The attenuated yellow fever (YF) vaccine is one of the most successful vaccines ever developed. After a single dose administration YF vaccine can induce balanced Th1/Th2 immune responses and long-lasting neutralizing antibodies. These attributes endorsed it as a model of how to properly stimulate the innate response to target protective immune responses. Despite their longstanding success, attenuated YF vaccines can cause rare fatal adverse events and are contraindicated for persons with immunosuppression, egg allergy and age < 6 months and >60 years. These drawbacks have encouraged the development of a non-live vaccine. The aim of the present study is to characterize and compare the immunological profile of two adjuvant formulations of an inactivated YF 17DD vaccine candidate. Inactivated YF vaccine formulations based on alum (Al(OH)3) or squalene (AddaVax®) were investigated by immunization of C57BL/6 mice in 3-dose or 2-dose schedules, respectively, and compared with a single dose of attenuated YF virus 17DD. Sera were analyzed by ELISA and Plaque Reduction Neutralization Test (PRNT) for detection of total IgG and neutralizing antibodies against YF virus. In addition, splenocytes were collected to evaluate cellular responses by ELISpot. Both inactivated formulations were able to induce high titers of IgG against YF, although neutralizing antibodies levels were borderline on pre-challenge samples. Analysis of IgG subtypes revealed a predominance of IgG2a associated with improved neutralizing capacity in animals immunized with the attenuated YF vaccine, and a predominance of IgG1 in groups immunized with experimental non-live formulations (alum and AddaVax®). After intracerebral (IC) challenge, attenuated and inactivated vaccine formulations showed an increase in neutralizing antibodies. The AddaVax®-based inactivated vaccine and the attenuated vaccine achieved 100% protection, and alum-based equivalent formulation achieved 70% protection.

A point-of-care dot blot ELISA assay for detection of protective antibody against canine adenovirus, canine parvovirus, and canine distemper virus is diagnostically accurate.

To determine diagnostic accuracy of a point-of-care antibody-screening test by determining sensitivity, specificity, and overall accuracy when compared to reference standard tests for antibody against core vaccine viruses canine adenovirus (CAV), canine parvovirus (CPV), and canine distemper virus (CDV). A further aim was to provide the practitioner with information to guide selection of vaccinal antibody testing methods. Canine sera from across North America were submitted to a fee-for-service titer-testing laboratory. Samples came from healthy pet dogs with known core vaccination history (n = 431) as well as unvaccinated dogs held in isolation (132). This study examined a total of 563 samples for CDV/CPV and 183 for CAV. Serum virus neutralization assays determined antibody titers for CDV and CAV. Hemagglutination inhibition assay determined antibody titers against CPV. All sera were also tested by point-of-care dot blot ELISA (index test). For all 3 viral antigens, the index test provided sensitivity ranging from 96.03% to 96.75% and specificity ranging from 87.50% to 94.33%. Overall accuracy ranged from 93.43% to 95.91%. The index test correlates well with reference standard tests and is a reliable, rapid screening test for detection of protective vaccinal antibody against CAV, CDV, and CPV in healthy dogs over 20 weeks of age. An accurate assessment of immunity allows clinicians to administer core vaccines appropriately as needed, avoiding unnecessary risk of adverse vaccine events.