US authorities refuse to use AZ's nasal flu vaccine

AstraZeneca (AZ) has taken an $80 million hit after US authorities said its nasal flu vaccine should not be used.

The Advisory Committee on Immunization Practices of the Centers for Disease Control (CDC) and Prevention said FluMist Quadrivalent live attenuated vaccine should not be used in any setting in the US for the 2016-17 flu season.

In the full year 2015 FluMist Quadrivalent sales were $206 million – but demand is expected to be very limited in the second half of this year.

AZ said in a statement that it will write down the value of its inventory by around $80 million in the second quarter, although financial guidance for 2016 remains unaffected.

The decision was based on effectiveness data from the last three flu seasons in the US, which indicated FluMist Quadrivalent did not demonstrate statistically significant effectiveness in children aged 2-17.

AZ, which owns FluMist through its $15.6 billion purchase of US biotech MedImmune (pictured) in 2007, said the CDC's effectiveness data contrasted with its own studies, as well as preliminary independent findings by public health authorities in other countries.

The CDC's data showed the vaccine was 46-58% effective against circulating strains during the 2015-16 season.

The CDC says that when there is a good match between the strains in the vaccine and those circulating, vaccines are typically 50-60% effective. AZ is working with the CDC to better understand its data and ensure the vaccine is used in future seasons in the US.

AZ faces the patent expiry of its cholesterol medicine Crestor (rosuvastatin), but hopes to build sales in the long term with a raft of new drugs.

CEO Pascal Soriot in 2014 set a sales target of $45 billion by 2023, as the company successfully fought off a takeover by Pfizer.

The company has also sold off several medicines to raise funds for investment in new drug R&D.