The US Food and Drug Administration (FDA) has approved MedImmune's, the global biologics arm for AstraZeneca PLC, FluMist Quadrivalent (Influenza Vaccine Live, Intranasal), a vaccine to prevent seasonal influenza in people ages 2 years through 49 years. The company submitted the sBLA early in the second quarter of last year.

FluMist Quadrivalent is the first influenza vaccine to contain four strains of the influenza virus, two influenza A strains and two influenza B strains. All other currently available licensed seasonal influenza vaccines are trivalent, containing three strains [two strains of type A influenza (A/H1N1 and A/H3N2) and one B lineage strain].  

In recent years, influenza B strains from two different lineages (B/Yamagata and B/Victoria) have circulated.  The quadrivalent vaccine includes strains from both lineages, helping provide protection against both B lineages.  The first of its kind approval for FluMist Quadrivalent reinforces MedImmune’s commitment to innovation within the infectious disease area.

“According to the Centers for Disease Control and Prevention (CDC), since the 2001-2002 season, influenza B viruses from both lineages have co-circulated in the USA,” said Stan Block, MD, FAAP, Professor of Clinical Paediatrics at the University of Kentucky College of Medicine in Lexingtonand at the University of Louisville School of Medicine.  “In the United States, in 5-of-the-10 influenza seasons between 2001 and 2011, the predominant circulating influenza B lineage was different from the one selected for inclusion in the trivalent vaccines.  The CDC has estimated that between 2001 and 2009, 2.7 million fewer Americans would have gotten the flu if all influenza vaccines had been quadrivalent.”

In pivotal clinical studies conducted in children and adults 2-49 years of age, FluMist Quadrivalent was compared to two trivalent formulations of MedImmune’s licensed seasonal influenza vaccine, FluMist (Influenza Vaccine Live, Intranasal).  

FluMist Quadrivalent had a safety profile generally comparable to the trivalent FluMist formulations, and immunogenicity to individual vaccine strains was comparable in trivalent and quadrivalent formulations.  Further, the addition of the second B strain did not result in immune interference to other strains included in the vaccine.   

“This is the first quadrivalent influenza vaccine approved and MedImmune is pleased to be able to take the next steps in making this product available to the public. We believe that the inclusion of an additional B strain in an annual influenza vaccine could provide a direct health benefit to individual vaccine recipients in the event that the correct B lineage either is not selected for inclusion in a trivalent vaccine, or if both lineages co-circulate,” said Bahija Jallal, MedImmune’s executive vice president of Research and Development.