Comparison of Four Different Types of Carriers for the Growth of Vero Cells and Propagating Rabies Virus for Production of Human Rabies Vaccine

In this study, capability of Vero cells for growth on FibraCel disks were compared on 3 kinds of microcarriers including Cytodex-1, Cutodex-3, and Sigma Solohill in 500 ml Spinner flasks in both serum contained medium (DMEM+10% Fetal Calf Serum, FCS) and serum-free medium (VP-SFM). The propagation of fixed PV (Pasteur Virus) strain of rabies in Vero cells, for production of rabies vaccine, grown under the above conditions were studied and compared.

Stepwise perfusion mode in growth phase and batch mode were applied in the virus production step by the use of M199 +0.2% Bovine Serum Albumin (BSA) and VP-SFM as serum containing and serum-free media, respectively. The available surface area provided by the carriers, and primary cell density in the experiments were assumed the same (about 12,000 cm2 and 12,500 cells/cm2, respectively).

The highest cell density was achieved on FibraCel disks in DMEM equal to 7.1 ±0.7×106 cells /ml on day 9, while the lowest cell density was obtianed on Cytodex-3 in VP-SFM equal to 2.91 ±0.2×106 cells/ml. The highest virus titer (55.18 ±4.4×106 Fluorescent Focus Unit,FFU/ml) was gained in VP-SFM containing FibraCel disks, and the lowest titer (3.66 ±0.4 ×106 FFU/ml) was resulted on Cytodex-3 in M199.

In these experiments, FibraCel disks supported the growth of Vero cells better than the microcarriers, and the use of DMEM for propagation of Vero cells and VP-SFM for proliferation of rabies virus showed better results. The experimental vaccine prepared by collected virus from VP-SFM has an acceptable potency of 2.75 IU. Based on these results and to the relative ease for making FibraCel disks, we recommend the use of this carrier for propagation of Vero cells and production of rabies virus.