The Vero cell line has been managed with the Cell Bank system to produce at the 142nd passage IPV, OPV and rabies vaccines since 1982 by Pasteur Mérieux Serums & Vaccins (PMsv). The safety of the cell line was regularly validated at the Working Cell Bank (WCB) level according to the WHO and European Pharmacopoeia requirements for absence of bacteria, fungi, mycoplasma and viruses. A special emphasis was devoted to research on the absence of simian viruses (SV40, SIV, Retro-D virus and simian CMV). All these specific researches were negative. At a low level of passage, the Vero cells are not tumorigenic. Vaccines have been prepared in low passage level Vero cells and together with the excellent downstream purification have resulted in excellent safety as attested by pharmacovigilance of more than 100 million doses of IPV during 12 years, more than 20 million doses of rabies vaccine during 10 years and more than 1 billion of OPV during eight years.