New Zealand Ministry of Health to consider Vaxigrip vaccine trial results

May 4 2005

Pharmac and the New Zealand Ministry of Health are aware that Sanofi-Pasteur has been running a clinical trial to demonstrate the efficacy of their influenza vaccine, Vaxigrip.

Earlier this year the New Zealand Government's medicines regulating body, Medsafe, limited use of Vaxigrip to healthy individuals younger than 65 who have had previous exposure to recent strains of influenza, after Sanofi-Pasteur informed Medsafe that they made an error in the manufacture of the Southern Hemisphere influenza vaccine and that it did not meet the potency standards for the A Wellington influenza strain.

The decision to limit use of Vaxigrip to patients at low risk of the complications from influenza was made by Medsafe following a review of published literature about the possible efficacy of influenza vaccines containing lower doses of influenza virus particles. The review indicated that the sub-potent vaccine was likely to be effective in the otherwise healthy population, but may be less effective in other patients. Sanofi-Pasteur acknowledged Medsafe's assessment and agreed to perform clinical studies examining the likely efficacy of the vaccine in low and higher risk patient groups as a way of providing evidence that the vaccine could be used in a wider group of patients.

Deputy Director General of Public Health Dr Don Matheson says "The current limitations on the use of Vaxigrip will remain until the trial results have been examined in detail by Medsafe. "

Medsafe spokesman Stewart Jessamine confirmed that it received information about the clinical trial late last Friday afternoon. "We will be giving it urgent consideration and we will be reporting on our progress by the end of Monday."

In view of the manufacturing problems at Sanofi-Pasteur and the questions about the efficacy of Vaxigrip in patients at high risk from the complications of influenza, Pharmac and the Ministry of Health urgently sought supplies of full-strength vaccine from around the world and are now committed to over 518,000 injections from other suppliers. The first 108,000 have arrived and have been distributed already. At least another 180,000 will arrive in the country this week with the remaining 230,000 arriving the following week.

Dr Matheson says “Based on previous years' usage, the 518,000 vaccines purchased should more than cover the eligible population who seek vaccination”.

Pharmac's medical director Dr Peter Moodie says “We had to commit to purchasing the full-strength stock from other suppliers to ensure immunisation of the at-risk population, particularly the elderly. It would not have been acceptable to wait for the results of this trial and take the risk that the results may then turn out to be unsatisfactory.

“Although we are pleased to see Sanofi-Pasteur claim positive results from this trial on 140 volunteers, Medsafe must be the final arbiters on whether to remove the restrictions on use of Vaxigrip.

"These delays arose because of a manufacturing error by the world’s largest maker of influenza vaccines. Sanofi-Pasteur are responsible for the current state of affairs and are fully liable for the extra costs that have been incurred,” says Dr Moodie.