Hemagglutination inhibition (HI) tests against whole virus (WV) influenza B/Singapore/222/79 antigen detected prevaccination serum antibody in only 15 (20%) of 50 predominantly elderly volunteers and fourfold or greater titer rises in only three (6%) after they received 1981-1982 trivalent influenza vaccine containing antigens of this virus. HI titers against ether-treated (ET) B/Singapore/222/...

Hemagglutination inhibition, enzyme-linked immunosorbent assay (ELISA), and passive latex agglutination were used to test 495 human serum samples for determination of rubella immunity. Overall agreements for immune status were as follows: hemagglutination inhibition versus ELISA, 94.7% (469 of 495); hemagglutination inhibition versus passive latex agglutination (1:10 dilution), 99.2% (491 of 49...

As pigs are susceptible to infection with both avian and human influenza A viruses, they have been proposed to be an intermediate host for the generation of pandemic virus through reassortment. The broad susceptibility of pigs to influenza viruses emphasizes the importance of surveillance of swine influenza virus. Thus, A latex agglutination test (LAT) was developed for rapid detection of antib...

Complement fixation (CF) was compared to hemagglutination inhibition (HI) as a method for identifying antibody responses to influenza virus vaccination. CF assays were performed at two different laboratories using paired (pre- and postvaccination) sera from 38 vaccinated laboratory employees; HI assays were performed at a third laboratory. As expected, most vaccinees (31/38 = 82%) responded to ...

An inactivated, alum-adjuvanted, whole-virion H5N1 vaccine had been evaluated previously. Hemagglutination inhibition (HI) assays showed that the antibody levels declined significantly, with 4.8%-20.8% and 0%-18.8% of participants retaining seroprotection (HI titer >or=1:40) 6 and 12 months after the second dose, respectively. A third dose of the same vaccine given 12 months after the second do...

Antigens for Grand Arbaud, Hazara, and California arboviruses were able to agglutinate goose and either dog, hamster and guinea pig, or hamster red blood cells (RBC) to the same titer at the same pH; in hemagglutination-inhibition (HI) tests, titers for homologous and related sera were the same with these different types of RBC or occasionally one dilution higher with the mammalian cells. Antig...

BACKGROUND Avian influenza viruses represent a growing threat of an influenza pandemic. The co-circulation of multiple H9N2 genotypes over the past decade has been replaced by one predominant genotype-G57 genotype, which displays a changed antigenicity and improved adaptability in chickens. Effective H9N2 subtype avian influenza virus vaccines for poultry are urgently needed. OBJECTIVE In thi...

Materials and methods: The hemagglutinin genes from 37 δ-cluster SIV isolates were fully sequenced. The isolates were antigenically categorized using a high throughput serum neutralization (HTSN) assay incorporating antisera generated against the four currently circulating clusters of H1 SIV and a commercial vaccine containing a δ-cluster SIV isolate. A subset of the isolates were further chara...

Since outbreaks of highly pathogenic avian influenza (HPAI) in both human and poultry from 2003, it is critical to have effective vaccines. A cDNA fragment coding the entire hemagglutinin (HA) gene derived from an H5N1 strain (A/duck/China/E319-2/03) was cloned and expressed using the baculovirus system. Two weeks after receiving two doses of recombinant HA (rHA) vaccines, chickens develop high...

Abstract Fowl adenovirus infections have a significant economic impact, especially in the production of broilers. It is considered leading cause three syndromes: adenoviral gizzard erosions and ulcerations, inclusion body hepatitis, hepatitis-hydropericardium syndrome. A critical feature this virus its immunosuppressive effect, via suppressing humoral cellular immunity. In study, we examined im...