Practice question

Vero cells are particularly valuable for vaccine production and virology because deletion of interferon alpha/beta genes prevents establishment of antiviral state normally triggered by viral RNA sensing via RIG-I and MDA5 activating IRF3. Consequently viruses replicate to high titers enabling efficient bulk production under Good Manufacturing Practice. Poliovirus inactivated polio vaccine, rabies vaccine, Japanese encephalitis vaccine, and rotavirus vaccine are produced in Vero microcarrier cultures. Regulatory agencies accept Vero because extensive documentation demonstrates absence of tumorigenicity at low passages and effective removal of host cell DNA during downstream purification using benzonase and chromatography. Compared to human diploid strains MRC-5 with limited lifespan of 42 doublings, Vero provides indefinite expansion lowering costs. In diagnostic virology, Vero supports plaque assays for virus titration due to clear cytopathic effect. Limitations include non-human glycosylation patterns differing in sialic acid linkages, making them less ideal for studies requiring authentic human post-translational modifications, where HEK293 or HepG2 lines are preferred for metabolism and protein folding investigations.