PowderMed's vaccine technology could treat flu pandemic more quickly than conventional technology

Oxford, UK-based developer and manufacturer of DNA-based vaccines, PowderMed, says its H5N1 avian influenza vaccine could be made more quickly than competitor vaccines, should a avian flu pandemic hit the UK, and it is urging the UK government to invest in manufacturing capacity for the product now.

Current global vaccine manufacturing capacity could produce around 300m doses of standard human influenza vaccine a year, which PowderMed argues is insufficient for some avain flu vaccines currently under development.

Its DNA vaccines require only 2µg per dose, which means 240g is enough for the 120m doses required to vaccinate the whole of the UK. But investment is required in manufacturing capacity to bring the drug on-line in the event of a pandemic.

It will take 18 months to two years to commission and fully validate new manufacturing capacity, irrespective of the vaccine technology chosen, says PowderMed.

Current vaccine manufacturing depends on an egg-based process and in the face of a pandemic this process could take six months before the first vaccine is produced. In the past, pandemics have killed most victims in the first 3 - 6 months, which means an egg-based vaccine would not catch the early spread of the infection. In addition, an avian flu epidemic may totally devastate the egg-laying hen population, resulting in no eggs and no vaccines.

While some investment is going into flu vaccines produced in mammalian cell lines that will avoid some of the issues of egg-based vaccines, PowderMed argues they still take a long time to manufacture.

DNA-based vaccines offer the potential to be produced within three months of a new flu virus being confirmed, taken together with a simple needle-free delivery system without the need for cold storage.

Dr Clive Dix, ceo and co-founder of PowderMed has produced an H5N1 avian influenza vaccine, delivered by a Particle Mediated Epidermal Delivery (PMED) system, whereby gold particles coated in the vaccine DNA are propelled into the immunologically active antigen presenting cells of the skin using high-pressure helium.

The new DNA-based avian flu vaccine in development would offer a rapid six weeks response to the potential global health emergency during the first six months of a pandemic, when the majority of mortalities would occur. It requires no cold storage and, being needle-free, is simple to administer.

This H5N1 vaccine is now being manufactured ready to enter the clinic in 2006. By 2007 it is expected that this, and PowderMed's annual flu vaccine will have completed Phase II clinical trials.