February 17, 2006
Science may be another step closer to a human vaccine to protect against the lethal H5N1 strain of avian, or bird flu.
An Australian pharmaceutical company, CSL Ltd., has announced that the vaccine triggered an immune response it predicts will equate with "a good level of protection" in "about half" of the 400 healthy adult volunteers tested.
Avian influenza has now spread to Western Europe, with cases reported most recently in France, following the discovery of the highly pathogenic H5N1 strain in wild swans in Greece and Italy earlier this week.
The H5N1 strain has killed over 90 people in Asia over the last three years, and subsequently spread to Russia, Kazakhstan and Mongolia last year. The last few months have seen the deadly virus afflict flocks of wild migratory birds in Romania, Turkey, Bulgaria, and as far as Nigeria.
An Iraqi man who died last month has been confirmed as that country's second human case of infection with the H5N1 bird flu virus, the World Health Organisation (WHO) said. But tests on another 14 people proved negative, the WHO said in a statement.
The Australian vaccine trial, conducted at the Murdoch Children's Research Institute in conjunction with Melbourne University and the Royal Adelaide Hospital, has shown the candidate vaccine to be well-tolerated in the study population.
Importantly, the company said it confirmed that when used in conjunction with a stimulant, or 'adjuvant', two standard doses of the vaccine will create an appropriate human immunological response in a significant number of volunteers.
"We have learned three very important facts from this trial," Professor Terry Nolan, the Principal Investigator said.
"Firstly, we can confirm it is actually possible to vaccinate humans against this bird virus using existing technology; secondly, we know we will need to use two doses of a candidate vaccine and an adjuvant to achieve a satisfactory immune response; and finally, we will need to do further research to trial a higher dose of vaccine across a wider age range so that we can protect as many people as possible, and demonstrate safety."
"CSL will continue to work closely with the Therapeutic Goods Administration (TGA), on the development of a core pandemic vaccine dossier, so that we can be ready to produce a safe and effective vaccine in the event of a pandemic," Dr Andrew Cuthbertson, Chief Scientific Officer at CSL Ltd, said.
"We will be discussing what further trial work needs to be done to determine the optimum dose of antigen needed as part of the final vaccine program."
The company said the Office of the Gene Technology Regulator (OGTR) has also licensed CSL's influenza vaccine manufacturing facility to make the pandemic vaccine, giving CSL the capability to produce antigen for further clinical trials and a vaccine stockpile as soon as required.
CSL has recently announced that it will be doubling its manufacturing capacity, which will put the company in an excellent position to respond to the need for influenza vaccine should a pandemic occur in future.
