The influenza vaccine market has grown considerably since 2009 with the introduction of several new types of influenza vaccines along with new delivery methods, including vaccines that use insect and animal cells for production instead of chicken eggs.
A “high-dose” influenza vaccine targeting those over age 65 years was approved by the FDA in 2009 and became available in the U.S. for the 2010-2011 flu season. This vaccine contains four times the amount of antigen as other flu vaccines and is supposed to stimulate a stronger immune response that will produce more antibodies and, theoretically, give the elderly better protection from getting sick with influenza.
In 2012, the FDA approved the first quadrivalent influenza vaccine, containing two type A and two type B influenza viruses. FluMist Quadrivalent, the live attenuated influenza vaccine, became available for the 2013-2014 flu season, and several quadrivalent inactivated injectable vaccines followed soon afterward. Quadrivalent vaccines add another strain of type B influenza virus to the traditional trivalent vaccines, which contain two strains of type A influenza virus and one strain of type B influenza virus, with the goal of improving flu vaccine effectiveness.
The first cell-based influenza vaccine, Flucelvax, was approved by the FDA in 2012, using canine (dog) kidney cells instead of chicken embryos to produce the vaccine. In 2013, Flublok, a recombinant influenza vaccine using armyworm caterpillar cells instead of chicken embryos for production, was approved for use in adults 18 to 49 years of age. Flublok quadrivalent received FDA approval for use in adults 18 and older in July of 2016.
