Comparison of titers obtained with H5pp versus MN assays for two panels of paired sera.

<p>Titers (reciprocal dilution of serum that gives 50% neutralization) were determined for sera from elderly (>65 yr) recipient of H5N1 vaccine selected to include 16 with pre-vaccination MN H5N1 titer ≥20 and 10 randomly selected seronegative persons with MN titer <20 and HI <8. The post vaccination was sampled 21 days post vaccination. The graph (A) shows the correlation of antibody titers in pre- (circles) and post (square) vaccination sera obtained with the H5 MN (sanofi pasteur method) and H5pp tests for those who were MN seropositive (black markers) and seronegative (open markers) pre-vaccination. Graph (B) shows the pre- and post H5N1 vaccination H5pp antibody titers in those with (“seropositive”) and without (“seronegative”) pre-vaccine antibody. For computation, the sera with undetectable antibody titers were given the value of 10. Positivity criterion (titer≥20) is represented by dashed lines.</p

Comparison of H5 neutralizing antibodies tested by MN and H5pp tests for different age groups.

<p>Titers were measured from paired sera of 98 children (A, B), 20 adults (C, D) and 118 elderly (E, F) given seasonal influenza vaccination; (G, H) 42 pairs sera from adults recipient of H5N1 clinical candidate vaccines. Dashed line marks the positivity criteria (titer≥20). Each line represents a paired serum from one individual. Where more than one person has identical pre and post antibody titers, the number of persons with these overlapping results is denoted as n. The MN titers were determined at HKU using the MN-HKU method (see methods).</p

Effect of seasonal vaccination on H5 neutralizing antibody titers measured by the microneutralization (MN) and the H5pp tests in paired sera from children, adults, and elderly after vaccination with seasonal influenza vaccine and H5N1 vaccine.

a<p>Patient cohorts from Hong Kong.</p>b<p>Patient cohorts from Europe.</p>c<p>N: Number of paired samples.</p>d<p>For the computation of geometric mean titers, negative sera (titer <20) are assigned value of 10 (first dilution tested 20). Student's t-test was used to calculate p-value.</p

Comparison of H5pp and MN tests by Bland & Altman method.

<p>On the x axis, the means of the H5 titers observed with the two methods are shown for individual samples. On the y axis, the difference between the methods divided by the means of the titers presented in percent. The limits of agreements are depicted. A total of 101 sera were included in the analysis. Bland and Altman plot, N  = 101. Bias: 31.9% [95% Confidence Interval  = +17.1% to +46.7%]. Limits of agreement  = −115.6% and +179.5%.</p

Time of seroconversion and mean antibodies titers measured 3 weeks after onset of disease or presumed exposure.

<p>*MN =  standard microneutralization test; *H5pp =  Pseudotyped H5 particles-based microneutralisation test.</p><p>**Only available among H5N1-infected patients.</p

Timing of sera collection, neutralizing antibodies titers and clinical outcomes from 11 patients with clinically apparent H5N1 virus infection, 2003/2004.

<p>*MN =  standard microneutralization test; *H5pp =  pseudotyped H5 particles-based microneutralization test.</p

Identification of a Novel Sulfonamide Non-Nucleoside Reverse Transcriptase Inhibitor by a Phenotypic HIV-1 Full Replication Assay

<div><p>Classical target-based, high-throughput screening has been useful for the identification of inhibitors for known molecular mechanisms involved in the HIV life cycle. In this study, the development of a cell-based assay that uses a phenotypic drug discovery approach based on automated high-content screening is described. Using this screening approach, the antiviral activity of 26,500 small molecules from a relevant chemical scaffold library was evaluated. Among the selected hits, one sulfonamide compound showed strong anti-HIV activity against wild-type and clinically relevant multidrug resistant HIV strains. The biochemical inhibition, point resistance mutations and the activity of structural analogs allowed us to understand the mode of action and propose a binding model for this compound with HIV-1 reverse transcriptase.</p></div

H5 neutralizing antibody titers by H5pp (1a) and MN (1b) tests in 31 asymptomatic/mild individuals.

<p>Orange lines: Fig. 1a: Linear regression line (slope of –0.06, p value  = 0.172). Fig1b: Linear regression line (slope of –0.31, p value  = 0.024). Cross points: Seropositive cases' neutralizing antibody titers at Weeks 7, 9, 48 and 51 after exposure (n = 54). Green line: Threshold titer at 80.</p

Characteristics of individuals tested positive by serology in Cambodia and Vietnam.

<p>Characteristics of individuals tested positive by serology in Cambodia and Vietnam.</p

Identification of IPK1 as a potent antiretroviral hit compound.

<p>A. Chemical structure of the <b>IPK1</b> compound. B. Dose-response curve of <b>IPK1</b> and comparison to reference anti-HIV drugs. The IC₅₀ value was characterized in CEMx 174-LTR-GFP CG8 cells infected by HIV-1_LAI. C. <b>IPK1</b> activity defined by IC₅₀ characterization in HeLa-LTR-GFP cells upon HIV-1_LAI infection. D. <b>IPK1</b> activity against the multidrug resistant virus HIV-1_RTMDR/MT-2 in CEMx 174-LTR-GFP CG8.</p