The coming era of quadrivalent human influenza vaccines: Who will benefit?

Abstract

Influenza vaccines form the mainstay of public health and personal protection against infection with seasonal influenza viruses. These vaccines are designed to protect people against infection with the currently circulating influenza viruses. Since the late 1970s, this has required the use of a trivalent vaccine consisting of two influenza A viruses and one influenza B virus. However, since the early 2000s, a second lineage of B viruses has regularly circulated in many countries that is quite distinct, with only low levels of cross protection between the two lineages. Due to the difficulties in determining which B lineage will circulate, and matching this with the vaccine to be administered ..