Standardization of the hemagglutination inhibition (HAI) assay for influenza serology is challenging. Poor reproducibility of HAI results from one laboratory to another is widely cited, limiting comparisons between candidate vaccines in different clinical trials and posing challenges for licensing authorities. In this study, we standardized HAI assay materials, methods, and interpretive criteri...

The immunity to pandemic influenza A(H1N1)pdm09 in Sweden before and after the outbreaks in 2009 and 2010 was investigated in a seroepidemiological study. Serum samples were collected at four time points: during 2007 (n = 1968), in October 2009 (n = 2218), in May 2010 (n = 2638) and in May 2011 (n = 2513) and were tested for hemagglutination inhibition (HI) antibodies. In 2007, 4.9% of the popu...

BACKGROUND In the present study, we analyzed the presence of antibodies to four different influenza viruses (pH1N1, hH1N1, swH1N1, and swH3N2) in the sera of 2094 backyard pigs from Mexico City. The sera were obtained between 2000 and 2009. OBJECTIVES The aim of this study was to perform a retrospective analysis of the 2000-2009 period to determine the seroprevalence of antibodies against pH1...

Monoclonal antibodies were derived against the SA11 simian, NIC bovine, and Wa human rotavirus strains and characterized by enzyme-linked immunosorbent assay, plaque neutralization, and hemagglutination inhibition. Several strain SA11-specific antibodies were found to have neutralizing and hemagglutination-inhibiting capacity.

BACKGROUND When the novel H1N1 influenza A strain appeared in April of 2009, development of novel H1N1 vaccines became a public health priority. METHODS We conducted a phase‐2, multicenter, randomized, placebo‐controlled, observer‐blind clinical trial of a 2009 H1N1 vaccine in 1313 young (age, 18-64 years) and older (age, >or=65 years) adults. Participants were randomized 1:4:4:4 to receive 2...

BACKGROUND To evaluate the temporal trends of seroprevalence to pH1N1 among the Guangdong population following 2009 H1N1 pandemic wave, we conducted three cross-sectional serology surveys in 2010. METHODOLOGY/PRINCIPAL FINDINGS Three surveys were carried out consecutively in 2010 from January 8 to January 24, from March 15 to April 10 and from August 23 to September 4. Sample populations comp...

Avian influenza (AI) H9N2 has been reported from poultry in India. A seroepidemiological study was undertaken among poultry workers to understand the prevalence of antibodies against AI H9N2 in Pune, Maharashtra, India. A total of 338 poultry workers were sampled. Serum samples were tested for presence of antibodies against AI H9N2 virus by hemagglutination inhibition (HI) and microneutralizati...

The use of several methods to differentiate myoglobin from hemoglobin has been investigated. The immunochemical methods, particularly those of hemagglutination inhibition and radioimmunoassay, are the most useful. This report summarizes work in the Ames Research Laboratory over the past 17 years with the several methods.

Indirect hemagglutination inhibition tests were employed to detect slime in concentrations as low as 1 mug/ml. Increasing concentrations of slime resulted in proportionately greater inhibition of hemagglutination. Peritoneal aspirates and plasma of mice injected with slime were shown to exhibit the inhibitory activity of slime. The rapid dissemination of slime into the peripheral circulation wa...

Secretory immunoglobulin A (sIgA) antibodies are the first line of defence at the genital mucosa, and are thought to hinder viral infections by binding to conformational epitopes on the viral capsid. To investigate if cervical sIgA binds to conformational epitopes of the Human papillomavirus type 16 (HPV16), cervical mucus samples from 109 HPV16-infected patients were examined in a HPV16 virus-...