Why are vaccine adjuvants necessary?
Vaccinations do not reflect latest medical findings.
(From a thesis on pediatric vaccines from Tasmania University:)
a quote from chapter "Conclusion":
"16.1 IMMUNOLOGY AND IMMUNISATION
As has been demonstrated in this thesis, at all levels of scientific knowledge and
endeavour relating to the creation of vaccines there are complexities and
uncertainties, and sometimes these are not acknowledged. The physical
attributes and mechanisms of the immune system reported as facts in standard
immunological texts are the subject of considerable conjecture and dispute. This
includes the nature and function of cells and molecules that are central to current
understandings of the way immunisation operates, with the result thatvaccine
design is often achieved through empirical means without the support of a clear theoretical basis for the procedures, or a clear understanding of the reasons for the results obtained.
It is a natural process for the theoretical framework of scientific disciplines to evolve
over time, with cycles of stability interspersed by periods of turmoil and rapid
change as new paradigms replace old ones. Over the last decade immunology has
been experiencing such a change, with evidence of an increased dissatisfaction
with the traditional view that the central function of the immune system is to
discriminate self from nonself. A variety of new theories have been proposed, with
the most significant being the danger model that sees the immune system as
responding to unnatural cell death, and various perceptions of the immune system
as a regulator of homeostasis. Although there is evidence that these new theories are gaining some acceptance in a variety of areas of medical research, they have not yet become integrated into discussions on the theoretical basis for the development of vaccines. This is a matter for concern as they carry significant implications for vaccine design, in particular the need for vaccines to provide appropriate "danger" signals to stimulate the immune system.
The attenuated, killed or particulate nature of pathogens included in vaccines do not
generally, on their own, provide sufficient stimulus or "danger" to provoke an
adequate immune response. Vaccine designers therefore rely heavily on the use of
various adjuvants to assist this process. These adjuvants are diverse in nature and little is understood about their mode of operation. Many new adjuvants are being trialled for human use, but all have significant limitations.
Particular care needs to be taken in the evaluation and approval of those intended for use in neonates and infants. The discussion of neonatal tolerance provides further support for the new theories in immunology. There is evidence that the current practice of administering large doses of antigen to infants to overcome the phenomenon of neonatal tolerance may be erroneous. This conclusion is based on in vitro studies that show that a low to moderate dose of antigen is more effective than a large one. This has been supported by the effectiveness of reduced dose vaccines in the field.
The crucial factor is not the amount of antigen, but the way in which it is presented to the immune system. In other words there is not the need to flood the neonatal system with a large amount of "nonself", but rather to present the antigen in such a manner that it is interpreted as a "danger" to be dealt with in such a way that a memory of that antigen persists."