In the film Contagion, Dr. Ian Sussman played by Elliott Gould is asked by Dr. Ally Hextall (Jennifer Ehle) to stop his research, which he later defies and ends up developing the virus in a special kind of cell. Why is that?
As I recall it was because Sussman was not working in a secure enough lab.
Research such as this has levels of bio-containment
A biosafety level (BSL) is a set of biocontainment precautions required to isolate dangerous biological agents in an enclosed laboratory facility. The levels of containment range from the lowest biosafety level 1 (BSL-1) to the highest at level 4 (BSL-4). In the United States, the Centers for Disease Control and Prevention (CDC) have specified these levels.
Dr. Ellis Cheever: From here on out I want no one working on this except the BSL-Four.
The CDC had declared that research in levels less than BSL-4 should be curtailed and Sussman's facility did not have that level assigned...it was BSL-3 (I believe).
When the CDC realized how dangerous the pathogen was, Ellis Cheever—played by Laurence Fishburn—made the decision that only labs accredited at Biosafety Level 4 (BSL-4) could research the pathogen. Sussman’s lab was only accredited at BSL-3.
Apparently, those levels are real https://en.wikipedia.org/wiki/Biosafety_level