Definition: Compose a new way to ask the same question. The new question must be asking the exact same thing as the original question does. Without any other information, you should be able to tell that the original question and the new question are the same. Preserve bracketed phrases in your new question. You can change the rest of the question provided the above requirements are satisfied. The new question must have a natural, fluent formulation, as if it were composed by a native English speaker. You will be given three pieces of information to help you create better questions. Those are: "Answer": the answer to the question, e.g., "Honolulu". "Answer Type": the type of the answer, e.g., "Location". "Auxiliary Information" is a detailed description of some concepts mentioned in the question, if any.
Input: original question: How many drug classes include [BCG vaccine]?
answer: 2
answer type: Drug class.
auxiliary information: A vaccine containing bacillus Calmette-Guerin (BCG), an attenuated strain of Mycobacterium bovis, with non-specific immunoadjuvant and immunotherapeutic activities. Although the mechanism of its anti-tumor activity is unclear, immunization with BCG vaccine likely activates a Th1 cytokine response that includes the induction of interferon. Vaccination with BCG vaccine may be immunoprotective against infection with Mycobacterium tuberculosis.

What number of drug classes is [BCG vaccine] included?