Protein Sciences announced that the first doses of Flublok (trivalent recombinant hemagglutinin [rHA] influenza vaccine) for the 2013–2014 season will be released in time for vaccinations to start before Thanksgiving.  Flublok is the first protein vaccine to be made in a 100% egg-free system without growing influenza viruses.

RELATED: Immunization Resource Center

Flublok is a trivalent composition of recombinant influenza hemagglutinin (rHA) proteins that are manufactured using Protein Sciences’ BEVS (baculovirus expression vector system) technology and expresSF+ cell line. Flublok is highly purified and it contains three times the amount of active ingredient in traditional influenza vaccines, with no preservatives (eg, thimerosal), antibiotics, or adjuvants. 

Flublok is available as a single 0.5mL dose for IM injection. To ensure adequate supply and delivery of Flublok, vaccinators are recommended to place their orders as soon as possible by calling (800) 843-7477 or online at

For more information call (800) 843-7477 or visit