Bid rent theory in the central business district (CBD) [edit]. Land users, whether they be retail, office, or residential, all compete for the most accessible land within the CBD. The amount they are willing to pay is called bid rent.
Recombinant or purified protein vaccines consist of protein antigens that have either been produced in a heterologous expression system (e.g., bacteria or yeast) or purified from large amounts of the pathogenic organism.
A vaccination is an injection of a dead bacterium. Your body then recognizes this bacterium and your immune system fights it off. See the related links for more information. A vaccine is a biological preparation that establishes or improves immunity to a particular disease. Vaccines can prevent or ameliorate the effects of infection by a pathogen.