Merck & Co, Inc has entered into an exclusive agreement with CSL Biotherapies, a subsidiary of CSL Limited, to market and distribute Afluria (Influenza Virus Vaccine), CSL's seasonal influenza (flu) vaccine, in the US, for the 2010/2011-2015/2016 flu seasons. CSL and Merck have been partners in vaccine development and marketing since 1980.

Under the terms of the agreement, Merck will assume responsibility for all aspects of commercialization of Afluria in the US. CSL will supply Afluria to Merck and will retain responsibility for marketing the vaccine outside the US. Specific financial details of the agreement were not disclosed.

Afluria was approved by the US Food and Drug Administration (FDA) in September 2007. It is indicated for the active immunization of persons age 18 years and older against influenza disease caused by influenza virus subtypes A and type B present in the vaccine. This indication is based on immune response elicited by Afluria, and there have been no controlled trials demonstrating a decrease in influenza disease after vaccination with Afluria.

"Adult vaccines are an integral part of preventive healthcare and continue to be a strong focus for Merck," said Margaret G McGlynn, president, Merck Vaccines and Infectious Diseases. "Afluria is an important addition to our robust adult vaccine portfolio and provides an opportunity for us to help address the public health need for flu vaccination in the US."

With the addition of seasonal flu vaccine, Merck will market eight of the 10 vaccines on the recommended immunization schedule for adults in the US.

CSL Biotherapies recently announced that the FDA licensed a new vaccine filling and packaging facility in Kankakee, Illinois. The facility includes a high-speed, single-dose vaccine syringe filling line and will primarily provide filling and packaging services for influenza vaccine supply to the US market.