A French team led byEpixis S.A. has developed an HCVvaccine that triggers both a T cell response and broadly neutralizing antibodies in macaques.1 Because of the ability to elicit both types of immune responses, the vaccine could have advantages over other HCV vaccines in development that focus only on T cell responses or that elicit neutralizing antibodies that do not attack the multiple genotypes of HCV.
Six companies have HCV vaccines in early stage clinical trials (see "HCV vaccines in clinical development").
HCV is difficult to neutralize because there are at least six distinct genotypes with more than 50 known subtypes. Genotypes 1a, 1b, 2b and 3a are the most common in the U.S., but even in a single infected individual, the virus is not homogeneous.
Epixis' vaccine has three components based on HCV genotype 1a: an adenovirus vector