FDA Approves New, More Quickly Produced Flu Vaccine

The new vaccine, Flublok, is made using cultured insect cells and can be produced much more rapidly than conventional flu vaccines, which are grown in chicken eggs.

The FDA has approved a new seasonal flu vaccine that can be made more rapidly than the current vaccine. The approval of Flublok, which is manufactured by Protein Sciences Corporation, was announced on January 16, 2013.

The conventional method of making flu vaccine involves growing the flu virus in chicken eggs and then inactivating or killing it, a process that takes months from start to finish. Production of Flublok, by contrast, involves growing the hemagglutinin protein from the flu virus in cultured insect cells and takes significantly less time. Hemagglutinin is the protein that allows the flu virus to enter cells. A part of all inactivated flu vaccines, it prompts the production of antibodies that prevent the flu virus from causing infection.

“This approval represents a technological advance in the manufacturing of an influenza vaccine,” said Karen Midthun, MD, director of the FDA’s Center for Biologics Evaluation and Research, in a press release. “The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic, because it is not dependent on an egg supply or on availability of the influenza virus.”

Flublok has been approved for use by adults aged 18 to 49 years, although Protein Sciences hopes to receive approval for everyone older than 18 years later this year. The company plans to make approximately 150,000 doses of Flublok available during the current flu season and to ramp up production for the 2013-2014 season. Like the conventional flu vaccine for the 2012-2013 season, Flublok is designed to protect against 2 influenza A strains and 1 influenza B strain.

The FDA previously rejected 2 applications for approval of Flublok and requested further safety testing. A clinical trial comparing Flublok to placebo found that the vaccine was 44.6% effective against all flu strains, not just the 3 strains included in it.

Flublok’s approval comes in the midst of a severe flu season in which there have been concerns about shortages of seasonal flu vaccine. For the week ending January 19, 2013, there was widespread flu activity in 47 states, according to the Centers for Disease Control and Prevention. However, the approval of Flublok does not appear to have been timed to address the need for more vaccine.

NOTE: This article has been updated since it was first posted, with the addition of the quote from Dr. Karen Midthun.