Influenza A H2N2 virus, also known as the Asian flu, spread worldwide from 1957 to 1967, although there have been no cases reported in humans in the past 40 years. A vaccination program was introduced in Japan in the 1960s. Older Japanese donors could have been naturally infected with the H2N2 virus or vaccinated in the early 1960s. Human intravenous immunoglobulin (IVIG) reflects the epidemiol...

Highly pathogenic H5N1 avian influenza viruses emerged in 1996 and have since evolved so extensively that a single strain can no longer be used as a prepandemic vaccine or diagnostic reagent. We therefore sought to identify the H5N1 strains that may best serve as cross-reactive diagnostic reagents. We compared the cross-reactivity of 27 viruses of clades 0, 1, 2.1, 2.2, 2.3, and 4 and of four c...

UNLABELLED Increased detection of enterovirus 68 (EV68) among patients with acute respiratory infections has been reported from different parts of the world in the late 2000s since its first detection in pediatric patients with lower-respiratory-tract infections in 1962. However, the underlying molecular mechanisms for this trend are still unknown. We therefore aimed to study the antigenicity a...

A sensitive immunoassay procedure for the detection of the thrombopoietic-stimulating factor (TSF) has been developed. This procedure Is similar to the hemagglutination-inhibition (HAl) technique that is available for erythropoietin. For the production of TSF, sheep were made thrombocytopenic by the Injection of antiplatelet serum. TSF from sheep sera was partially purified by column chromatogr...

Three assays for detection of rubella antibodies, Rubella G (fluorescence immunoassay [FIA]), Rubacell (passive hemagglutination), and Rubaquick (passive hemagglutination with rotation), were compared with hemagglutination inhibition. A total of 100 serum specimens were selected, 68 of which had an FIA value of less than or equal to 25. On initial testing, among the four tests, there was agreem...

Various concentrations of pig, guinea pig, chicken, and turkey erythrocytes (RBCs) were cryopreserved and compared with fresh RBCs in hemagglutination and hemagglutination inhibition tests. Hemagglutination and hemagglutination inhibition titers obtained with cryopreserved or fresh RBCs from the same donor differed by not more than one twofold dilution. RBCs cryopreserved at a concentration of ...

conclusions the aiv loaded into cnp vaccines induce appropriate antibody titers, after a single immunization, while requiring a low dose of antigen. the cnp also represent an interesting new platform for antigen delivery and a promising adjuvant candidate for h9n2 inactivated influenza vaccine. results the cnp did not cause any mortality or side effects, when chickens were administered the prep...

BACKGROUND Little is known about the dynamics or magnitude of antibody response in patients with influenza A (H1N1) pdm09-associated pneumonia. We described and compared the antibody response to influenza A (H1N1) pdm09 in patients with and without pneumonia. METHODS We collected serum samples and determined antibody titers by the hemagglutination inhibition (HI) and microneutralization (mNT)...

The single radial hemolysis (SRH) test was compared with the hemagglutination inhibition (HI) test for establishing rubella immune status and diagnosing recent infection. Correlation between mean SRH diameters and HI titers greater than or equal to 1:8 was high (R = 0.99). It is suggested that a level of greater than or equal to 5 IU represents low-level antibody and that greater than or equal ...

Heat-stable inhibitors (HI) of hemagglutination by influenza viruses have been extracted from the chorioallantoic membrane (CAM) of chick embryos, and in the preceding paper (1) it was shown that their general characteristics resembled those of inhibitors isolated from other biological materials which have been identified as mucoprotein in nature. Inhibitory activity of CAM extracts against hea...