GlaxoSmithKline (GSK) said yesterday the US FDA had approved its four-strain influenza vaccine Fluarix Quadrivalent for children aged three and over and adults.
The approval – the first for the new vaccine anywhere in the world – comes as the US flu vaccine market is gradually shifting from trivalent to quadrivalent products, which provide broader protection against the virus.
Most of the other main manufacturers are working to bring four-strain vaccines to market, and analysts at JP Morgan predicted recently that the 2013 flu season in the US would predominantly see adoption of the newer versions.
GSK said that Flurarix Quadrivalent is the first intramuscular vaccine to cover against two influenza A and two influenza B subtypes, unlike traditional trivalent vaccines that protect against two influenza A subtypes and a single influenza B subtype.
“Trivalent influenza vaccines have helped protect millions of people against flu, but in six of the last 11 flu seasons, the predominant circulating influenza B strain was not the strain that public health authorities selected,” commented Leonard Friedland, head of clinical development at GSK’s North America vaccines programme.
Since 2000, two B influenza subtypes – Victoria and Yamagata – have been circulating with various degrees of prevalence.
That has resulted in a “mismatch” between the B strain included in trivalent vaccines and the predominant circulating B strain on occasions, which in turn has resulted in an increased risk of influenza-related morbidity among all age groups, according to the pharma company.
GlaxoSmithKline said that it will make Fluarix Quadrivalent available in time for the 2013/2014 influenza season in the US, and also plans to fulfil orders for the traditional trivalent vaccine.
AstraZeneca’s Medimmune division won FDA approval for its four-strain vaccine FluMist Quadrivalent in March, 2012, while Sanofi Pasteur also has its own candidate – Fluzone Quadrivalent – in late-stage development and could be ready to supply the 2013-14 season.
Novartis has concentrated on developing cell-manufactured flu vaccines, having recently won approval in the US for its Flucelvax trivalent candidate, and is arguably lagging in the quadrivalent stakes.
Meanwhile, smaller vaccine players are also working on four-strain shots, notably Novavax whose candidate recently cleared phase II testing.