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.
Recombinant Flu Vaccines. There is a third production technology for flu vaccines that was approved for use in the U.S. market in 2013 and that involves using recombinant technology. This production method does not require an egg-grown vaccine virus and does not use chicken eggs at all in the production process.ecombinant flu vaccine is the only 100% egg-free vaccine on the U.S. market. There are other vaccines on the U.S. market that use similar recombinant manufacturing processes.