Vacutainer 4 ml tubes

Study participants (age range 25-67, Table 1) had either been vaccinated previously with a 13-valent pneumococcal conjugate vaccine (PCV13, Prevenar 13, Pfizer; n=5) or were pneumococcal vaccine-naïve (n=4). Within this study, two physiological opsonophagocytic killing assays were compared using venous blood specimens from these nine healthy volunteers. The assay using hirudin-anticoagulated whole blood collected in S-monovette^® 1.6 mL tubes (Sarstedt, Germany) was compared to the assay using EDTA-anticoagulated whole blood collected in BD Vacutainer^® 4 mL tubes (BD, Switzerland) washed with DPBS and reconstituted with serum collected in Vacuette^® CAT serum tubes (Greiner Bio-One, Switzerland). Blood from an additional volunteer, who had recently received a MenACWY vaccine booster immunization was used for control experiments analyzing meningococcal clearance.

Six healthy volunteers were recruited upon informed and written consent. Only subject 12 had received an infant Hib vaccination (Table 1). All six received one dose of the Hib vaccine (ActHIB^®, Sanofi Pasteur SA) in the framework of this study. Venous blood was taken before, 2 weeks and 2 months after this vaccination. Vacuette^® CAT serum tubes (Greiner Bio-one) were used for collection of sera and preservation of their terminal complement activity was reconfirmed (Complement TCC, Svar Life Science AB). Ethylene diamine tetraacetic acid (EDTA)-anticoagulated whole blood was collected in BD Vacutainer^® 4 mL tubes (BD).