Gina,
We are obviously not the only people who are confused about whether BCG is a virus or a bacterium. Try Googling each term and you will get the medical community calling it both. There is actually a HUGE difference in a bacteria and a virus. My Doctor referred to it as a "live attenuated virus."
But, as you say, it is not as important to us as it is to researchers. It does make you want to do your homework when so much is at stake. At least it makes me want to do my homework....
This is from medicine.net
PRECAUTIONS: Because this medication contains active virus, it is important to pour household bleach into the toilet after urinating and before flushing for up to 6 hours after receiving the medication. This will prevent the infection caused by the virus from spreading.
www.medicinenet.com/bcg_vaccine-chemotherapeutic/article.htm