Vaccines against viral infections like polio, chickenpox, measles, and viral hepatitis are manufactured by producing large quantities of viral particles in a scaled-up tissue culture system. A handful of historical cell lines like Vero (green monkey kidney) and MDCK (canine kidney) are approved by the FDA for viral vaccine production. However, other than clone selection and substrate adaption, relatively little has been done to improve the inherent viral production capacity of the cell lines. ATCC used CRISPR/Cas9 gene editing to create improved versions of cell lines commonly used for viral vaccine manufacturing. These cells produce model clinical viruses at titers 10-fold higher than the corresponding parental cell line, which has the potential to significantly reduce costs associated with virus and viral vaccine production.