1. Introduction
A general concern in cell-based manufacturing of recombinant proteins, including vaccines, is the potential contamination of the cell culture with viruses, which has had severe consequences for patients and manufacturers (Barone et al., 2020; Berting, Farcet, & Kreil, 2010). With the pandemic emergence of SARS-CoV-2, the exposure of biomanufacturing cell lines to a new virus has become a possibility, and to safeguard biomedicines it is important to understand whether the virus is even capable of infecting bioproduction cell lines, and if so, whether the event would be detected by adventitious agent tests (AAT) that are part of biomanufacturing quality control.
This study investigated four widely used biomanufacturing cell lines, i.e. CHO and Vero, as well as the two human cell lines HEK-293 and HT-1080, for their susceptibility to infection with SARS-CoV-2.
In addition, adventitious virus testing (AAT) as routinely performed for in-process control testing per regulatory guidance (US Food and Drug Administration, 1993; ICH, 1997), was evaluated for its ability to detect SARS-CoV-2 infection if it were to occur. As MRC-5 cells are part of the AAT detector cell line panel (Figure 1), these cells were also tested for their susceptibility to SARS-CoV-2.