At this time, generic Comvax is not available. Comvax (Hib vaccine and hepatitis B vaccine) is a "biologic" medication, which means that it is under different regulations than most other drugs. However, the rules and laws surrounding biologics are changing, and generic versions of the vaccine could become available fairly soon.
Comvax® (Hib vaccine and hepatitis B vaccine) is a combination vaccine. It contains two standard childhood vaccines: a hepatitis B vaccine and a Hib vaccine (Haemophilus influenzae type b vaccine). The vaccine is made by Merck & Co., Inc. There are no generic versions of Comvax.
Technically, Comvax is considered a "biologic" medication and is, therefore, under different rules and laws than most other medications. At this point, generic biologics, including generic Comvax, are not allowed to be made. However, the laws are changing, and it is likely that generic biologics will be permitted in the near future.
When the patents for regular drugs expire, other manufacturers can apply to make generic versions. These companies need to submit a little information proving that their product is equivalent to the brand-name drug, but they do not have to repeat all of the human studies to show the drug to be safe and effective. Human studies are expensive and time-consuming, and generic medications are less expensive because they do not need all the human studies.
However, biologics (medications made using live cells or organisms, also known as "biopharmaceuticals") are regulated under a different set of laws. Under these laws, there is no way for a generic biologic to be approved, unless the generic manufacturer completes all of the human studies necessary to approve a brand-new drug.
Because such studies are extremely expensive, it is likely that a generic biologic would not be any less expensive than the brand-name product. Essentially, if a generic biologic were to be approved, it would not really be a generic version, but a new and separate drug that would not be equivalent to the brand-name product.
However, recent legislation is attempting to change these laws. It is predicted that new laws and regulations will allow generic biologics in the near future.