The US Food and Drug Administration (FDA) has announced the approval of a new type of flu vaccine that provides an alternate option to those unable to consume egg-based products.
The new vaccine, Flublok, is a trivalent influenza vaccine manufactured by Meriden, CT-based Protein Sciences Corporation. Unlike other flu vaccines, which utilize a live virus to infect chicken eggs, Flublok is made from only a single hemagglutinin protein from the influenza virus. That protein is manufactured by inserting a gene for the protein into baculovirus, an insect virus, which then infects a proprietary cell line.
The company explains on its website that the process could come to be used for a wide range of other vaccines in the future, including against HPV, SARS, Ebola, diabetes and various types of cancer. It could also be used for gene therapy applications and other biologics-based therapies for healing wounds, repairing tissue or acting as an anti-viral.
To date, three products including Flublok have cleared Phase III clinical development using the technology, which is called the Baculovirus Expression Vector System (BEVS). One of the other products, Glybera, is currently marketed in the EU as a gene therapy product intended to treat lipoprotein lipase deficiency (LPLD). The other, Diamyd, is an experimental type 1 diabetes vaccine being developed by Diamyd medical. The company has said its results did not show a statistically significant result relative to a placebo, and has withdrawn its application from before EU regulators.
The Flublok vaccine is notable for another reason: Its development process is considerably faster than that of egg-based vaccines. The entire process can be completed within approximately two months, while normal vaccines take six months or more to make. That speed has attracted US biodefense dollars and interest from the US Department of Health and Human Service's Biomedical Advanced Research and Development Authority (BARDA), which apparently wants to further develop and scale up not only Flublok, but another product called Panblock (bird flu variant H5N1) as well.
FDA's approval notice for Flublok notes this potential as well. "This approval represents a technological advance in the manufacturing of an influenza vaccine," said Karen Midthun, director of FDA's Center for Biologics Evaluation and Research (CBER). "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."
Regulators said they would re-evaluate the vaccine each year to determine its applicability to the upcoming flu season. The product reportedly has a shelf life of 16 weeks, or slightly longer than it takes to manufacture.