This document discusses strategies for improving cell culture technology for influenza vaccine production. It outlines the development of cell lines like MDCK and PER.C6 that are used for large-scale vaccine production. Reasons for low viral yields in cell culture include low cell density, cell death, and strains not growing well. Strategies to improve yields include manipulating the cell line, virus strain, infection conditions, and culture conditions to optimize cell survival and virus replication. The goal is to establish robust and scalable cell culture processes for purer and faster influenza vaccine production compared to egg-based methods.