Process development for pandemic influenza VLP vaccine production using a baculovirus expression system

Table 1 Characteristics of Sf-21 and High Five™ cell growth and baculovirus virus and H7N9 TW-VLP production in a 300-mL shake flask

Cell line	Sf-21 cell	High Five™ cell
Medium	Sf-900™ II SFM	Express Five® SFM
Seeding cell density (cells/mL)	2.0 × 10⁵	2.0 × 10⁵
Cell doubling time (hour)^a	33.3	18.3
Harvested cell density (cells/mL)	1.5 × 10⁶	3.3 × 10⁶
Fold increase of cell density	7.4	15.3
Baculovirus virus (virion/mL)^b	1.0 × 10⁸	3.1 × 10⁶
HA titer (HAU/50 μL)	64	512

^aThe cell doubling time was calculated using the following formula: DT = time (T) x ln2/ln (Xe/Xb), where T is the incubation time in any units, Xb is the cell number at the beginning of the incubation period, and Xe is the cell number at the end of the incubation period
^bThe baculovirus titer (virion/mL) was calculated using the TCID₅₀ method

ISSN: 1754-1611