Intranasal influenza virus vaccine

Extract from report of GACVS meeting of 3-4 December 2003, published in the WHO Weekly Epidemiological Record on 16 January 2004

The Committee considered safety issues pertaining to a new generation influenza vaccine, administered by the intranasal route. It is a live vaccine, and there are concerns about viral shedding and thus of the potential risk of person-to-person transmission. In the United States, the press has reported that more than 5 million doses have been manufactured, but probably no more than 400 000 had been distributed by the end of November 2003. Comprehensive surveillance has been put in place for monitoring safety. GACVS will review in detail the post-licensure safety data of the vaccine at its June 2004 meeting.

Full report of GACVS meeting of 3-4 December 2003, published in the WHO Weekly Epidemiological Record on 16 January 2004

 

Bell palsy following intranasal influenza vaccination

Extract from report of GACVS meeting of 20-21 June 2002, published in the WHO Weekly Epidemiological Record on 22 November 2002

Results from a case–control study and a case-series analysis indicate a significantly increased risk of Bell palsy developing following intranasal immunization with a new vaccine. This inactivated influenza vaccine, composed of influenza antigens in a virosomal formulation with E. coli derived LT adjuvant, was licensed in Switzerland in October 2000. Following spontaneous reports of Bell palsy, the company decided not to market the vaccine during the following season.

In general, the etiology and pathogenesis of Bell palsy remain inadequately understood. The greater risk of Bell palsy following immunization with this vaccine may be due to specific vaccine components such as LT toxin, influenza antigens or virosomes, or simply to use of the intranasal administration route. It is thus possible that such complications of vaccine administration may also apply to other nasal vaccines. GACVS therefore recommends that any novel vaccine for nasal administration should be tested on a sufficiently large number of subjects before licensing and submitted to active post-marketing surveillance studies. Since the average time to onset of Bell palsy following intranasal immunization with this new vaccine was as much as 60–90 days, GACVS recommends that the follow-up period in the context of clinical trials should be routinely extended to 3 months following administration of a new intranasal vaccine.

Full report of GACVS meeting of 20-21 June 2002, published in the WHO Weekly Epidemiological Record on 22 November 2002