With the books closed on 2012, we can confirm--as expected--that a majority of the major FDA vaccine approvals went to trivalent influenza vaccines. (The FDA is continuing this trend with the first vaccine approval of 2013 going to Flublok, a trivalent influenza vaccine made using an insect virus expression system and recombinant DNA technology.) Manufacturers, after all, need to reformulate them each season. But two new quadrivalent flu vaccines from GlaxoSmithKline ($GSK) and AstraZeneca ($AZN) also joined the ranks, scheduled to hit the market later this year.
Of 11 major FDA vaccine approvals, 10 went to flu vaccines. (GlaxoSmithKline did get the OK for MenHibrix, a combination vaccine to prevent disease from meningococcal groups C and Y as well as Haemophilus influenzae type b, or Hib.)
GSK's Fluarix Quadrivalent and AstraZeneca's FluMist Quadrivalent should debut in time for the 2013-2014 flu season. Until February 2012, when the FDA gave FluMist Quadrivalent the go-ahead, all approved flu vaccines covered only two influenza A strains and one influenza B strain.
Trivalent influenza vaccines hit the market in the 1980s, Dr. Leonard Friedland, VP and head, GSK North America Vaccines Clinical Development and Medical Affairs, told FierceVaccines. World health experts and researchers select strains for a seasonal flu vaccine based on forecasts about which viruses will most likely cause illness in a given season. The idea is to match the strains in the vaccine with the strains making the rounds. By 2000, health experts noticed that two influenza B lineages--Yamagata and Victoria--began cocirculating.
"In 6 of the last influenza seasons, the predominant B strain that circulated was of a lineage not selected to be in the vaccine," Friedland said.
The World Health Organization recently called for manufacturers to start including a second B strain in their vaccines. For its part, GSK began working on a quadrivalent flu vaccine in 2010, Friedland said, the outcome being Fluarix Quadrivalent. The company has a second quadrivalent flu vaccine in the works.
"What we're excited about with the quadrivalent vaccine is now there won't be any question, 'Did we choose the right B strain in the vaccine?' Friedland said. "Because both B lineages will be in the vaccine. It provides the opportunity for broader protection in the vaccine."
Still, only about 47% of individuals received the flu vaccine in the 2011-2012 season. And the U.S. Centers for Disease Control reports an estimated 36.5% got the jab by November this season. So there's a market present, it's just a matter of tapping into it.
We'll keep an eye on the quadrivalent flu vaccines as they roll out at the end of the year. Until then, take a look at which vaccines nabbed a major thumbs-up from the FDA in 2012. -- Alison Bryant (email | Twitter)