FDA Approves New Flublok Vaccine That is Egg-Free
The US Food and Drug Administration has approved a new flu vaccine which is manufactured in a way that bypasses the need for the virus to be grown in chicken eggs. Developed by a company called Protein Sciences, based in Connecticut, Flublok could be available within the next few weeks to better aid those during the current flu pandemic.
Flublok, which is approved for use in adults aged 18 to 49, protects against two influenza A strains – H1N1 and H3N2 – and one influenza B strain. It is made using a baculovirus expression system and recombinant DNA technology. The process involves producing large quantities of influenza hemagglutinin (found on the surface of influenza viruses and responsible for binding the virus to the cell that is being infected) for each of the vaccine strains in an insect cell line derived from the fall armyworm, the larval stage of a moth.
"While the technology is new to flu vaccine production, it is used to make vaccines that have been approved by the FDA to prevent other infectious diseases," the FDA said in a press release, noting that the technology allows for faster production, which could be helpful in a pandemic situation.
This is not the first time the vaccine has been up for FDA approval. In 2009, an FDA advisory committee narrowly voted against recommending approval citing insufficient safety data particularly for the older population, says Manon Cox PhD, president and CEO of Protein Sciences Corporation. However, the panel did agree that the vaccine was effective.
"What has happened since is we have done a lot of investigation in the cell substrate to further prove and demonstrate that that was safe and we have provided a lot of information that the manufacturing process was consistent and could be used to make many different hemagglutinins," Cox told MedPage Today.
Two studies have been conducted using Flublok. The largest study found that during the 2007-2008 flu season, the vaccine was shown to be 44.6% effective against all circulating strains of influenza. The most common adverse effects were pain at the injection site, headache, fatigue, and myalgia.
The FDA has asked Protein Sciences to conduct additional trials to evaluate Flublok’s safety in people older than 55. These will begin within the next few months and Cox expects approval to be expanded to older adults by the end of the year.
Trials will also be conducting studies on children ages 6 to 18 during the 2013-2014 flu season.
Protein Sciences could have around 150,000 doses of Flublok ready in the next couple of weeks. In the future, as it does with all influenza vaccines, the FDA will evaluate Flublok annually prior to use by the public to determine the best combination of flu strains the vaccine will protect against.
Reference: US Food and Drug Administration