Industrial-Scale Production of Inactivated Poliovirus Vaccine Prepared by Culture of Vero Cells on Microcarrier

In 1980, the authors reported preliminary results of large-scale production of inactivated poliovirus vaccine in which virus was produced in Vero cell culture on a microcarrier. For this first stage of development, 150-liter tanks were used. The virus is now produced in 1,000-liter tanks. The main point concerning the quality of Vero cells, namely the absence of tumorigenicity, has been demonstrated, qualifying them for use in the Institut M erieux cell bank. The purity of the cell line has also been determined by checking for the absence of bacteria, fungi, mycoplasmas, and viruses. The search for oncornavirus and for reverse transcriptase activity was carried out, and the results were negative but are not described in this paper. The quality of the purification process was checked by a search for residual cellular DNA in concentrated, purified, and inactivated vaccine. With use of a molecular hybridization procedure, a specific probe was prepared to detect approximately 50 pg of DNA per filter. The preliminary results show that the purification procedure fulfills the World Health Organization's requirements. T1 oligonucleotide mapping has also shown the identity of poliovirus RNA extracted from virus grown on Vero cells and that from primary monkey kidney cells. These data have led to the awarding of a license by the French government to the Institut M erieux for production of this new, reassessed, inactivated poliovirus vaccine.