Blood Sample Processing and Storage

Whole blood and serum samples were obtained from volunteers at each visit to the Clinical Research Center of Tel Aviv Sourasky Medical Center and transferred within 2 hours of collection to the School of Public Health Research Lab, at the Sackler Faculty of Medicine, Tel Aviv University for further processing and storage. Peripheral blood mononuclear cells (PBMC) were isolated from whole blood followed by activation or cryopreservation. Serum samples were centrifuged within 4 hours after collection and stored at -80 °C until further analyzed. The assay procedures and analyses of all parameters described below were identical in the phase I and follow-up studies. Samples of volunteers collected in the phase I study were retested in the same runs with the new samples obtained during the follow up. The results obtained at retesting were in all cases below 2-fold change in titer compared to the original data.