There are two ways to think about what the term "vaccine" represents. They are:

(a) A vaccine formula or a method of producing a given vaccine. At this level, a vaccine is just an idea, a recipe that anyone with a proper equipment can use to produce a vaccine product.

(b) An actual vaccine dose in a physical form (e.g. in a vial) that was manufactured by a company.

Discuss the rivalry and excludability of these two versions of a good, (a) and (b), and classify them into one of the 4 categories of goods. Do you think a competitive market will produce an efficient quantity of good (a)? What about good (b)? Carefully explain your reasoning. If one of the goods cannot be produced by a competitive market, what are the possible solutions to this problem?