It's not a vaccine - it's an altered tuberculosis bacteria.
http://www.bccancer.bc.ca/HPI/DrugDatabase/DrugIndexPt/BCGforBladder.htmBCG for Bladder
Other names: Bacille Calmette-Guerin, ImmuCyst® BCG Therapeutic, BCG-Cancer®
BCG is a drug that is used to treat bladder cancer by increasing your body's natural defenses. BCG comes from live bacteria (germs) similar to TB (tuberculosis). It is a cloudy liquid that is given through a small tube into your bladder.
Do not drink liquids for 2 hours before your treatment so your bladder will be empty.
Your doctor or nurse inserts a catheter (small tube) into your bladder and drains out any urine. The BCG is given into your bladder by attaching a syringe to the catheter. The amount given is 50 mL (less than 2 ounces). The catheter is then removed.
You will be asked to hold the BCG in your bladder as long as possible up to 2 hours after each treatment. At home, spend 1 of the 2 hours lying in bed.
Be sure to lie on your stomach for the first 15 minutes after treatment.
After lying on your stomach you may be advised to lay on your back for 15 minutes, then on your side for 15 minutes, and then on your other side for 15 minutes.
In other cases, after lying on you stomach for 15 minutes you may be advised to get up and move around. In either case this makes sure that the BCG completely covers the inside of your bladder.
Unless otherwise advised by your doctor you should drink lots of liquids for the next 24 hours. Try to drink at least twelve 250 ml (8 oz.) glasses per day and urinate frequently. This helps prevent bladder problems.
Sit down when you pass urine (for at least 6 hours after your treatment).
BCG is potentially infectious so you should take precautions when flushing the toilet.
You can do this by either flushing the toilet twice, or by disinfecting your urine in the toilet using non-diluted bleach. If you choose the bleach method, pour a cup of bleach into the toilet bowl every time you urinate for the first 6 hours following treatment. Leave bleach in the toilet bowl for 15 minutes before flushing.
Wash your hands well with soap and warm water. Wash clothes, bedding and toilet articles which have touched your urine in hot soapy water preferably with bleach.
Some other drugs such as prednisone (Deltasone®) or dexamethasone (Decadron®, Dexasone®, Hexadrol®) may interact with BCG. Tell your doctor if you are taking these or any other drugs as your dose may need to be changed. Check with your doctor or pharmacist before you start taking any new drugs.
BCG often causes a positive skin test for TB (tuberculosis). This does not mean that you have had TB.
The drinking of alcohol (in small amounts) will not affect the safety or usefulness of BCG.
The effect of BCG on sperm or on the baby during pregnancy is not known. It is best to use birth control while being treated with BCG. Tell your doctor right away if you or your partner becomes pregnant. Do not breast feed during treatment.
Tell doctors or dentists that you are being treated with BCG before you receive any treatment from them.