'Weak' flu vaccine passes test

Results from an Australian trial of sanofi pasteur's Vaxigrip vaccine "overwhelmingly support its effectiveness", the medical director of the company's Australian operation, Dr Victor Carey, said yesterday.

Sanofi sent the results to the Health Ministry on Friday, seeking an extension of the groups on which Vaxigrip can be used.

The ministry's medicines regulator, Medsafe, said last night that it would urgently consider sanofi's request and report on progress this afternoon.

The ministry's deputy director-general of public health, Dr Don Matheson, said, "The current limitations on the use of Vaxigrip will remain until the trial results have been examined in detail by Medsafe".

Medsafe in March restricted use of Vaxigrip injections to healthy people under 65 who had been exposed previously to influenza, after problems emerged with Vaxigrip in February that delayed the start of this year's vaccination programme.

Last week, elderly people and others with chronic health conditions, including heart disease, finally started being injected with full-strength doses of other flu vaccines sourced by health officials.

But only one-fifth of the 518,000 doses for these people have been distributed so far, so some patients wanting to be vaccinated last week were disappointed.

Vaxigrip was found to contain 10 - instead of the required 15 - micrograms of antigen for one of the three flu strains it is designed to protect against. Human error, at the French factories where it is made, was blamed.

Sanofi reasoned that Vaxigrip should be effective, despite the mistake, but the trial, co-ordinated by Adelaide University, was run to satisfy medicine regulators. It involved 140 adults, including 65 aged over 60.

Dr Carey said yesterday that European health authorities in the 1990s increased the required amount of antigen for each strain to 15 micrograms, from 10, despite questions about the need to do so.

An analysis of 20 clinical trials showed little difference in the human response to the different amounts.

Sanofi said that to satisfy European regulators, the human immune response of flu vaccine had to meet one of three criteria on levels of antibodies. Vaxigrip had met all three in the latest trial.

Pharmac's medical director, Dr Peter Moodie, said restricting Vaxigrip and finding full-strength vaccine doses was the right thing to do in March.

"If [we hadn't and] the trial results had been negative we would have been in a terrible situation now."

He would not say how much the vaccine debacle had added to the cost of the vaccination programme, but Pharmac maintained that sanofi was liable for the costs. This was unaffected by the trial results.