Comparison of indirect hemagglutination and indirect immunofluorescence tests with microneutralization tests for detection of type-specific Herpesvirus hominis antibody

1979 ◽  
Vol 9 (3) ◽  
pp. 384-390
Author(s):  
L D Johnson ◽  
D A Fuccillo ◽  
H Stalder ◽  
M A Oxman ◽  
C E Fraser ◽  
...  

Indirect hemagglutinating and immunofluorescent antibody responses to Herpesvirus hominis types 1 and 2 were compared to neutralizing antibody responses in infected humans from whom H. hominis type 1 or 2 was isolated. The indirect immunofluorescent antibody test was shown to be the most sensitive and specific for primary human infections. The sensitivity and specificity of the indirect hemagglutination and the immunofluorescent antibody tests were shown to be equal to that of the microneutralization test among patients who had primary or recurrent H. hominis type 2 infections. It is suggested that the indirect hemagglutination test is preferable for assaying large populations for previous infection with H. hominis type 2 because it is rapid, easier to perform, and more economical. The intermediate range of titer differences (deltat) between H. hominis types 1 and 2 previously reported to be due to infections with both viruses was shown to occur in all three tests among patients with primary infections with either virus.

2016 ◽  
Vol 68 (2) ◽  
pp. 271-275 ◽  
Author(s):  
A.M. Antonello ◽  
G.C. Cadore ◽  
F.L. Pivoto ◽  
G. Camillo ◽  
P. Braunig ◽  
...  

The aim of this study was to examine the intra-uterine exposure to Sarcocystis spp. antigens, determining the number of foals with detectable concentrations of antibodies against these agents in the serum, before colostrum ingestion and collect data about exposure of horses to the parasite. Serum samples were collected from 195 thoroughbred mares and their newborns in two farms from southern Brazil. Parasite specific antibody responses to Sarcocystis antigens were detected using the indirect immunofluorescent antibody test (IFAT) and immunoblot analysis. In 84.1% (159/189) of the pregnant mares and in 7.4% (14/189) of foals we detected antibodies anti-Sarcocystis spp. by IFAT. All samples seropositive from foals were also positive in their respective mares. Serum samples of seropositive foals by IFAT, showed no reactivity on the immunoblot, having as antigens S. neurona merozoites. In conclusion, the intra-uterine exposure to Sarcocystis spp. antigens in horses was demonstrated, with occurrence not only in mares, but also in their foals, before colostrum ingestion these occurrences were reduced.


2007 ◽  
Vol 15 (3) ◽  
pp. 397-401 ◽  
Author(s):  
T. Opriessnig ◽  
A. R. Patterson ◽  
J. Elsener ◽  
X. J. Meng ◽  
P. G. Halbur

ABSTRACT Due to the ubiquitous nature of porcine circovirus type 2 (PCV2) in the pig population and the increasing use of PCV2 vaccines in breeding herds, the majority of dams have been exposed to field PCV2 or PCV2 vaccines, resulting in piglets with varied levels of passively acquired PCV2 maternal antibodies. The objective of the current research was to investigate the influence of passively acquired anti-PCV2 antibodies on PCV2 vaccine efficacy. Sixty 26-day-old pigs were divided into four groups: vaccinated pigs with no maternal PCV2 antibodies at the time of vaccination (VAC-NEG; n = 9), vaccinated pigs with maternal PCV2 antibodies at the time of vaccination (VAC-POS; n = 21), nonvaccinated pigs with no maternal antibodies at the time of challenge (NVAC-CNEG; n = 15), and nonvaccinated pigs with maternal antibodies at the time of challenge (NVAC-CPOS; n = 15). Vaccinations and challenges were performed on trial days 0 and 28, respectively, according to group designation. The pigs were monitored for clinical signs of disease daily and weighed weekly, and blood was collected weekly. All pigs were necropsied on trial day 49, and tissues were evaluated for macroscopic and microscopic lesions. Serum was evaluated using PCV2 immunoglobulin G (IgG) and PCV2 IgM enzyme-linked immunosorbent assays, quantitative PCV2 PCR, and a serum PCV2 neutralizing antibody test. In comparison to NVAC-CPOS pigs, VAC-POS animals had significantly (P < 0.01) less severe microscopic PCV2-associated lymphoid lesions and significantly (P < 0.04) reduced PCV2 genomic copies in serum following PCV2 challenge. These results indicate that vaccination with Suvaxyn PCV2 One Dose reduces viremia and prevents microscopic lesions associated with PCV2 in the presence of maternal antibodies.


1987 ◽  
Vol 61 (2) ◽  
pp. 129-136 ◽  
Author(s):  
A. Ito ◽  
K. Onitake

ABSTRACTThe surface antigens of oncosphere, cysticercoid, adult scolex and adult strobila (other than scolex) of Hymenolepis nana differ critically from one another. When the oncosphere of H. nana undergoes differentiation and development into the mature tapeworm, the infected mouse first produces anti-oncosphere antibody, followed by anti-cysticercoid, anti-adult scolex and finally anti-strobila (other than scolex region) antibodies of IgG, IgM and IgA isotypes as detected by indirect immunofluorescent antibody test. The parasite changed its surface antigens throughout its differentiation and maturation, and all developmental stages were recognized by the infected mouse host. However, there appeared no further changes in surface antigens during aging after maturation. The antibody responses were always delayed compared with the differentiation and maturation of the parasite.


PEDIATRICS ◽  
1954 ◽  
Vol 14 (6) ◽  
pp. 573-586
Author(s):  
C. ARDEN MILLER ◽  
HERBERT A. WENNER

Thirteen of fourteen children with a clinical diagnosis of poliomyelitis showed high neutralizing antibody titers in tissue culture tests aganst prototype viruses, as early as two days after the first symptom, and persisting for as long as 18 months without significant change in titer. A significant increase in titer from that during the first week was occasionally encountered, but the initial titer was usually in the same range as that of the subsequent 18 months. The 14th child had antibodies against none of the prototype poliomyelitis viruses, though his clinical history was quite compatible with a non-paralytic infection. In the third month this patient's Type 2 antibody rose after six negative serums to 1:5120, possibly indicating an inapparent poliomyelitis infection several months after an erroneous diagnosis of poliomyelitis. Stool specimens were available from seven of the 14 children. Six Type 1 poliomyelitis viruses and one Type 2 virus were recovered from these stools. Neutralizing antibody titers against the patient's own virus closely paralled those against the homologous prototype virus. When differences did occur, they were in favor of higher antibody titers against the patient's own virus. Serums from 10 patients had antibodies against more than one prototype virus. With the exception of only two patients, antibodies against one of the prototype viruses were present far in excess of the others. Possible explanations for the heterotypic antibodies are discussed. Neutralization tests, as performed, appear to be of value in ruling out a diagnosis of poliomyelitis, but not in establishing the diagnosis.


2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S327-S328
Author(s):  
Jorge Pagura ◽  
Clovis Arns de Cunha ◽  
Roberto Nishimura ◽  
Sergio Wey ◽  
André Pedrinelli ◽  
...  

Abstract Background The Brazilian Football Confederation (CBF) protocol to control the spread of COVID-19 among professional soccer players is based on four cornerstone measures: (1) Tracing all symptomatic and asymptomatic COVID-19 cases by clinical monitoring and nasal swab SARS-CoV-2 RT-PCR testing up to 3 days before the soccer games; (2) Respiratory isolation of all SARS-CoV-2 positive players for at least 10 days, regardless symptoms; (3) All player with clinical suspicion of COVID-19 were immediately quarantined; (4) If a player became SARS-CoV-2 positive after the game, the other players were allowed to play the next game, if they remained asymptomatic and SARS-CoV-2 RT-PCR negative. Understanding how antibody responses to SARS-CoV-2 evolve can provide insights into therapeutic and testing approaches for COVID-19. In the present study we profile the antibody responses of players up to nine months from a SARS-CoV-2 positive RT-PCR test. Methods Serum samples were obtained from 955 soccer players, and analyzed at the same laboratory in São Paulo city, in the Hospital Israelita Albert Einstein. It was used the cPas Technology, the sVNT kit for detecting and measuring circulating neutralizing antibodies against the SARS-CoV-2 virus. Results Neutralizing antibody was positive for 416 samples (416/955=44%; C.I. 95%= [40%; 47%]). From the 955 soccer players, 454 had RT-PCR+ previously, up to nine months until the neutralizing antibody tests. From this 454 players, 172 (38%) had neutralizing antibody below 20% (C.I. 95% = [34%; 42%]), 30 (7%) between 20% and 30% (C.I. 95% = [5%; 9%]), and e 252 (56%) above 30% (C.I. 95% =[51%; 60%]). Antibody responses to SARS-CoV-2 were significantly higher in individuals RT-PCR+ (Table 1). There was no difference between the neutralizing antibody responses status to SARS-CoV-2 and the time between the RT-PCR+ and the neutralizing antibody test (p-value = 0.423; Figures 1 and 2, Table 2). Table 1. Neutralizing antibody responses to SARS-CoV-2. Figure 1. Scatter plot with Time between RT-PCR+ and neutralizing antibody (days) versus Neutralizing antibody levels. Table 2. Time between RT-PCR+ and neutralizing antibody (days) versus Neutralizing antibody levels. Conclusion This study found neutralizing activity of infection against SARS-CoV-2 in 63% RT-PCR+ individuals, but only in 26% in RT-PCR(-) players. Level of neutralizing antibody responses maintained stable until up to nine months after a RT-PCR+. Figure 2. Percentage of soccer players at each antibody level (below 20%, between 20% and 30%, and above 30%) versus time between the positive RT-PCR test and neutralizing antibody test (days). Disclosures All Authors: No reported disclosures


1952 ◽  
Vol 96 (5) ◽  
pp. 477-490 ◽  
Author(s):  
Johan Winsser ◽  
Albert B. Sabin

Quantitative neutralization tests in monkeys were carried out on sera obtained from 7 patients, 3 months, and 3 years after an attack of poliomyelitis. The serum specimens were tested against 100 to 1000 PD50 of the patient's own strain of virus, recovered during the acute phase of the illness; all the strains were Type 1. The 6 patients, aged 6 months to 13 years, who had a paralytic attack of the disease, all exhibited very high levels of neutralizing antibody at 3 years as well as at 3 months after onset. The 50 per cent serum dilution titers ranged from about 1:180 to at least 1:860. Since the maximum titers were not established, it is not known to what extent, if any, the level of antibody may have dropped over the 3 year period. One of the patients, with a diagnosis of non-paralytic poliomyelitis, had a negligible or questionable antibody response during convalescence and no demonstrable antibody at 3 years; there is justifiable doubt as to whether the Type 1 poliomyelitis virus recovered from this patient had actually caused infection. Tests for Lansing neutralizing antibody indicated that the 5 patients who had no evidence of previous infection with Type 2 poliomyelitis virus had not become infected with it during the 3 year period. This suggested that these patients did not live in an environment in which infection with poliomyelitis virus is frequent. It is concluded, therefore, that in human beings, paralytic infections due to Type 1 poliomyelitis virus produce large amounts of homotypic neutralizing antibody, which persists at high levels for a period of at least 3 years.


2021 ◽  
Author(s):  
Maria Ganczak ◽  
Marcin Korzeń ◽  
Ewa Sobieraj ◽  
Jakub Goławski ◽  
Oskar Pasek ◽  
...  

Abstract Background Polish teachers, as the priority group, were offered the ChAdOx1-S vaccine since February 2021. The objective was to investigate safety, tolerability and immunogenicity of this vaccine following two vaccine doses. Methods Teachers were invited for serological testing ≥8 weeks after second vaccination. Quantitative post-vaccination anti-spike antibody responses were measured using the Abbott SARS-CoV-2 IgG II Quant assay (detection threshold: ≥7.1 BAU/ml). Multivariable logistic regression methods were used to identify predictors of immunogenicity. Results Of 192 teachers, mean age 50.5±8.3 years, 83.9% were females. Median (range) dosing interval was 50 (14-95) days; median interval between the second dose and immunogenicity test was 69 days (range: 57–111). More than a half of teachers (58.3%) reported they would change the product for another (mostly mRNA) vaccine if there was such an opportunity. Adverse reactions after receiving the vaccine (either the first or the second dose) were reported by 79.2% teachers, more frequently after the first dose (84.9%), and were similar in nature to those previously reported: feeling feverish (44.8%), headache (41.7%), malaise, chills (both: 38.0%), injection-site tenderness (37.5%) and pain (32.3%). Less males than females (54.8% vs 80.1%) and older (aged ≥50 years) than younger teachers (65.7% vs 90.4%) reported side effects (p<0.002; p<0.0001, respectively). By ≥8 weeks after the boost dose, all teachers had neutralizing antibody responses. The median (range) anti-spike IgG reading was 525.0 BAU/mL (20.6-5680.0 BAU/mL); 1008.02 (115.3–5680.0) BAU/mL in teachers with evidence of prior infection and 381.42 BAU/mL (20.6–3108.8) in those without (p=0.001). Previous infection with SARS-CoV-2 and longer dose interval were both positive predictors of higher immunologic response (p<0.0001; p=0.01, respectively), with no evidence of differences by age, gender, BMI, smoking or comorbidities. Conclusions The results demonstrated good safety, tolerability and immunogenicity of the ChAdOx1-S vaccine. Immunization led to detectable anti-spike antibodies in all teachers. Our study justifies the longer dose interval as an important factor to enhance higher antibody response. Findings suggest that in immunocompetent vaccine recipients with an evidence of previous infection a delay regarding the second dose could be considered when careful management in the use of vaccine resources is needed.


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