Vaccine researcher critical of CSL, govt approaches to bird flu

A leading researcher has raised the ire of CSL (ASX:CSL), saying the Melbourne company is "making the wrong vaccine for bird flu."

Prof Graeme Laver told a press conference in Sydney that CSL was not making a whole vaccine but a split level virus vaccine, which he said would be "ineffective" against the disease.

In February, CSL reported what it described as encouraging results from its bird flu trial of 400 health adult volunteers. The vaccine triggered an immune response which the company predicted would equate with "a good level of protection" in "about half" of volunteers tested, according to the company.

CSL spokeswoman Rachel David defended the company's work. "Our trial results do not reflect [Laver's criticism], and we have done the largest trial world wide at the 15 microgram dose," David said. "It has provided us with a good evidence base and the clinical data says we are on the right track.

"CSL is the leading Australian manufacturer of flu vaccine with decades of experience and we are the best people to make the judgement about the clinical program. We stand behind our studies to date and we are encouraged by our results."

CSL hopes to be able to apply for approval of a prototype vaccine by the end of 2006, after it completes a study testing doses of 30 and 45 micrograms on 800 people ranging in age from six months to the very old.

Laver is a molecular biologist whose early work isolating influenza viruses from birds on the Great Barrier Reef was critical to understanding the ecology of influenza and led to the design of anti-viral drugs such as Roche's Tamiflu and GlaxoSmithKline's Relenza. He said those drugs were the most promising weapons against H5N1, as they blocked the activity in enzymes.

On-site diagnostics

Laver was also critical of the Australian government's decision to make Tamiflu available by prescription only. "It should be available in every chemist without a prescription," he said. "The strategy is totally wrong because Tamiflu works best six to 12 hours after the onset of fever. Once it comes on you want it and you want it now."

Laver suggested that pharmacists should be equipped with rapid-test diagnostic kits. "If you are positive you get Tamiflu... an advantage is that people who are infected and take the drug are immune." Laver also added that Tamiflu is "totally wrong for prophylactic prevention."

He said H5N1 infected people with great difficulty, but once it infected a person it could kill very quickly. "You don't want a strong immune system -- you want a strong antibody response," he said.

Prof Tony Cunningham, director of the Westmead Millennium Institute for Medical Research, added that H5N1 would affect a younger age group than normal flu due the strong immune response it provoked, and that the resulting inflammation could cause death by overwhelming the lungs and other organs.

He said that unlike normal flu, which starts with a high fever followed by a cough within 24 hours, with bird flu a cough was not invariable, making it harder to diagnose. Cunningham added that it was of major concern that before symptoms were evident, the virus could shed and spread.

Cunningham was also critical of rapid tests currently on the market, describing them as 80-88 per cent effective at best. He said the Australian government's recent funding for a rapid test diagnostic meant one could be developed in the next six to 12 months.