Flublok is made using recombinant DNA technology and contains hemagglutinin produced in an insect cell line. Approved by the FDA in January, it is the only completely egg-free flu vaccine available, prompting the Advisory Committee on Immunization Practices (ACIP) to add it to the guidance for the upcoming season at one of its regular meetings at CDC headquarters in Atlanta.
According to the previous algorithm for determining how people with egg allergies should be vaccinated, those who had a history of only hives upon exposure to egg were recommended to get inactivated influenza vaccine followed by an observation period of at least 30 minutes after administration to watch for reactions.
And those who had a history of some other reaction aside from hives -- such as cardiovascular changes, respiratory distress, gastrointestinal symptoms, and reactions requiring epinephrine or emergency medical attention -- were recommended to see a physician with expertise in management of allergic conditions for further evaluation.
For the upcoming season -- following a unanimous vote by ACIP -- Flublok (abbreviated RIV3) will be listed as an alternative in both scenarios, assuming the individual falls within the approved age range of 18 to 49.
A reference to RIV3 also will be made in added language referring to people who do not have a history of egg allergy but who may be at risk based on previously performed allergy testing. In that case, "consultation with a physician with expertise in the management of allergic conditions should be obtained prior to vaccination" or, if age appropriate, RIV3 can be given.
At the last meeting of ACIP in February, the committee approved the addition of four recently approved flu vaccines to the guidance for the 2013-2014 season. On Thursday, Sanofi Pasteur's Fluzone Quadrivalent -- approved by the FDA earlier this month -- was added, as well. It is the only quadrivalent flu vaccine approved for use in children younger than 2.
All of the quadrivalent vaccines will protect against two A strains -- H1N1 and H3N2 -- and two B strains -- one from the Yamagata lineage and one from the Victoria lineage.
One of the ACIP members, Tamera Coyne-Beasley, MD, MPH, reported that her institution, the University of North Carolina at Chapel Hill, receives clinical trial funding from Merck. The other committee members reported that they had no conflicts of interest.
