Flublok Quadrivalent influenza vaccine approved by FDA

The US Food and Drug Administration has approved privately-held US biotech Protein Sciences’ quadrivalent formulation of Flublok influenza vaccine, which protects against four strains of influenza, three of the same strains found in trivalent Flublok plus an additional B strain.

Significantly, the company states, Flublok Quadrivalent is the first and only high antigen content quadrivalent flu vaccine approved by FDA. It contains 3x more active ingredient than all other quadrivalent vaccines, making it a great choice for seniors and those with compromised immune systems, among others.

In a clinical study of 9,000 adults 50 years of age and older, people who received Flublok Quadrivalent were over 40% less likely to get cell-culture confirmed influenza than those that received a leading egg-produced quadrivalent flu vaccine. These results are relevant for trivalent Flublok, as the H3N2 component of the vaccine that is shared between trivalent and Flublok Quadrivalent predominately contributed to the improved efficacy