LAIV is a trivalent seasonal influenza vaccine which was first approved in the US in 2003 for use in individuals aged five to 49 years of age. In September 2007, the age range of the vaccine was extended by the FDA for use in children aged two to five years. However, this still only represents a small proportion of the key target population for seasonal influenza vaccination. The lack of approval in the elderly, the target group showing the highest seasonal flu vaccine coverage rates, has restricted the overall commercial potential of the vaccine, which only achieved sales of $53m in 2007.

The seasonal influenza vaccine market is a highly competitive field which is becoming increasingly commoditized as a result of the increasing number of available vaccines. Due to its intranasal mode of administration and very good efficacy in this age group, FluMist’s largest opportunity lies in the infant segment. However, it is questionable whether the cost-conscious European payers will opt to introduce FluMist readily following its European approval, if AstraZeneca decides to pursue a similar strategy as in the US, where the vaccine is marketed at a premium price compared to conventional seasonal influenza drugs.