Preclinical evaluation of Vaxfectin-adjuvanted Vero cell-derived seasonal split and pandemic whole virus influenza vaccines

Increasing the potency and supply of seasonal and pandemic influenza vaccines remains an important unmet medical need which may be effectively accomplished with adjuvanted egg- or cell culture-derived vaccines. Vaxfectin, a cationic lipid-based adjuvant with a favorable safety profile in phase 1 plasmid DNA vaccines trials, was tested in combination with seasonal split, trivalent and pandemic whole virus, monovalent influenza vaccines produced in Vero cell cultures. Comparison of hemagglutination inhibition (HI) antibody titers in Vaxfectin-adjuvanted to nonadjuvanted vaccinated mice and guinea pigs revealed 3- to 20-fold increases in antibody titers against each of the trivalent influenza virus vaccine strains and 2- to 8-fold increases in antibody titers against the monovalent H5N1 influenza virus vaccine strain. With the vaccine doses tested, comparable antibody responses were induced with formulations that were freshly prepared or refrigerated at conventional 2-8°C storage conditions for up to 6 mo. Comparison of T-cell frequencies measured by interferon-gamma ELISPOT assay between groups revealed increases of between 2- to 10-fold for each of the adjuvanted trivalent strains and up to 22-fold higher with monovalent H5N1 strain. Both trivalent and monovalent vaccines were easy to formulate with Vaxfectin by simple mixing. These preclinical data support further testing of Vaxfectin-adjuvanted Vero cell culture vaccines toward clinical studies designed to assess safety and immunogenicity of these vaccines in humans.

Application of the Laplace operator to scintigraphic images: comparison with conventional scintigraphy and digital filtering

The curvature scintigram is an image, obtained by applying the Laplace operator to nuclear medicine images, that shows local variations of count rate density. Applications to liver scintigrams are described. The diagnostic quality of the curvature scintigram is compared with that of the conventional and digitally filtered scintigrams, using a series of patients who have been categorized by histology or by transmission computer tomography. From our results, the curvature scintigram demonstrates an improvement over the subjective findings of clinicians. It enables the detection of an increased number of true-positives and a reduced number of false-positives.