prr anounce success

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Prima Biomed Limited (ASX: PRR) today announced that preliminary
experiments have been completed in a small number of sheep which have
all demonstrated strong immune responses following immunisation with
a DCtag vaccine.

The DCtag vaccine platform technology was first announced in November
2001 after very promising immune responses had been demonstrated in
animal tests. In a one-dose vaccination against malaria, mice were
successfully protected against a lethal malaria infection and high
antibody levels had continued to persist for 4 months.

In addition to promoting strong antibody responses, DCtag has
demonstrated strong killer cell type immune responses in mice. DCtag
pre-immunisation prevented tumour growth and immunisation eradicated
pre-existing tumours.

DCtag vaccines are unique as they promote a response by two immune
cell types - antibody and killer T-cell type immune responses.

Mr Marcus Clark, Chief Executive Officer of Prima Biomed said "The
outcome of this latest sheep trial is very encouraging and as a
result we will immediately commence further studies to give us a more
detailed picture of the immune response.

"The new study will determine the relative potency and spectrum of
activity of the immune response using a DCtag vaccine. These further
experiments will take up to 6 months and are designed to demonstrate
that DCtag can induce the same levels of antibody and killer T cells
in sheep as was demonstrated in mice.

"If successful Prima would then explore whether the antibodies and
killer T cells produced by DCtag provide protection against a known
infection in sheep, cattle or pigs. Such a study would involve first
vaccinating animals with a DCtag vaccine, exposing them to the
infectious organism of interest and then monitoring them to see if
they remain infection free. The company is currently evaluating
potential infectious disease models for this study.

"This progress is in line with milestones established in the Panvax
Business Plan.

"Such studies, in large animals, form part of the process of
collecting the necessary data for early human clinical trials. The
generation of this data also provides the company with potential
licensing opportunities with large veterinary supply companies. This
development has the potential to an early revenue stream," said Mr
Clark.

Inquiries:

Marcus Clark Chief Executive Officer 03 9287 0637
Rudi Michelson (Monsoon Communications) 03 9620 3199