We organic chemists have it easy compared to the cell culture people. After all, our reactions aren't alive. If we cool them down, they slow down, and if we heat them up, they'll often pick up where they left off. They don't grow, they don't get infected, and they don't have to be fed.
Cells, though, are a major pain. You can't turn your back on 'em. Part of the problem is that there are, as yet, no cells that have evolved to grow in a dish or a culture bottle. Everything we do to them is artificial, and a lot of it what we ask cultured cells to do is clearly not playing to their strengths. Ask Genzyme (GENZ): they use the workhorse CHO (Chinese Hamster Ovary) cells to produce their biologics, but they've been having variable yield problems over the past few months. Now it turns out that their production facilities are infected with Vesivirus 2117 - I'd never heard of that one, but it interferes with CHO growth, and that's bringing Genzyme's workflow to a halt. (No one's ever reported human infection with that one, just to make that clear).
I assume that the next step is a complete, painstaking cleanup and decontamination. That's going to affect supplies of Cerezyme (imiglucarase) and Frabazyme (agalsidase) late in the summer and into the fall, although it's not clear yet how long the outage will be. Any cell culture lab that's had to toss things due to mycoplasms or other nasties will sympathize, and shudder at the thought of cleaning things up on this scale.