A doctor's thesis on vaccine policies & science (or lack of)

[Guest guest]

Quite an interesting kind of " middle ground " thesis on pediatric

vaccines from Tasmania University:

http://adt.lib.utas.edu.au/uploads/approved/adt-TU20041117.161706/public/02Whole\

..pdf

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 that

vaccine

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. "