Saar Kuzi
Alessandra Coutinho Fernandes
William Cope
Richard Tapping
Kashif Ahmad
Reda Sadki
Shubhra Kanti Karmaker Santu
Adam P Rusch
Elle Meisner
Nereyda Ochoa
Landon J. Kunzelman
James DotimasFA16 Immunization Module’s Updates
Adjuvants in vaccine formulations
Adjuvants (from Latin, meaning to help) aid in the immune response to vaccines. It has been found that pure antigen only mounts weak responses. Surprisingly, it is the imperfect antigen solution – those with leftover impurities or added adjuvants – that mount the strongest responses from the innate and adaptive immune systems. As Dr. Tapping mentions in the podcast lecture on vaccination, adjuvants “increase the danger” of the antigen solution. Often, it is substances that are pro-inflammatory and somewhat toxic that aid in the response to antigen.
Aluminum compounds are the only adjuvants licensed in United States. The bulk of these compounds are termed alum. Alum activates the intracellular inflammation pathway in macrophages and dendritic cells, leading to production of IL-1β. IL-1β goes on to exert effects leading to local inflammation. Other common adjuvants in other parts in the world include various lipid products and bacterial components (have toxic effects, however).
As stated, adjuvants, through the production of proinflammatory molecules like IL-1β are responsible for the local inflammation response. This response is often what is referred to as the minor adverse reaction to vaccines. Pain, swelling, and redness at the site of injection are the most common reactions and occur with up to 80% of vaccine doses.
Aside from simply increasing the efficacy of vaccines, the use of adjuvants has the added benefit of reducing the necessary amounts of antigen (a product of the increased efficacy). This allows stocks of antigen to stretch further and reduces the possibility of vaccine shortages.
Sources:
CDC, "General Rules of Immunization"
Dr. Tapping's lecture slides
Adjuvants are pretty cool and their purpose definitely makes a whole lot more sense after learning the basics of immunology and how inflammatory cytokines are necessary to cause general localized inflammation and to recruit cells of the immune system. I also think it's really cool how because of adjuvants less of the actual antigen is required. This has to be extremely important for cutting costs in places where cost of a vaccine can be the limiting factor. I'm curious as to why other adjuvants that are used in other parts of the world aren't licensed here, especially if Aluminum is toxic to the CNS.
I find the use of adjuvants in vaccines to be incredibly fascinating. I wonder if there are any significant side effects that can be caused by the adjuvants beyond the localized inflammatory response. I have been told to wait in my physician's office for 10-15 minutes to make sure there were no adverse side effects so I could drive home safely. Reading this post leads me to believe that the potential side effects are not from the antigen itself, but the adjuvant. I wonder if it is possible that a simple vaccine adjuvant could lead to systemic inflammation.
The history here is fascinating. If any of you are curious see what you can find out about William B. Coley and the immunologists dirty little secret
I remember the first time I learned about adjuvants, it was interesting to me that imperfect antigen combined with these adjuvants provided the strongest immune response.
In response to the use of aluminum as the only licensed adjuvant in the U.S., doesn't aluminum exhibit some toxic effects, especially in the CNS? As future physician's, specifically those of us in family medicine, it's important for us to have patient compliance with vaccinations especially with children. I wonder how we'll overcome the vaccinations cause autism thinking with some individuals.