Human and veterinary vaccines are divided into five main categories: conjugate, toxoid, subunit, inactivated (killed), and live (attenuated) vaccines (1). The vast majority of currently licensed human and veterinary vaccines are inactivated or live (2, 3). They are produced mostly using adherent cells: primary cells such as chicken embryo fibroblasts (CEF), human diploid cells such as MRC-5, or continuous cell lines such as Vero and MDCK (4). The pioneering legacy inherited by vaccine manufacturing development has led to strategies for…