Influenza B Virus Strain For 2004-2005 To Be Confirmed In March
This article was originally published in The Pink Sheet Daily
Executive Summary
FDA committee recommends switch from a Victoria to a Yamagata lineage influenza B strain. For influenza A, New Caledonia (H1N1) strain will be retained, while a Fujian-like strain will replace this season's Panama-like strain.
|
FDA's Vaccine & Related Biological Products Advisory Committee will confirm its influenza B strain recommendation for the 2004-2005 vaccine during a March 17 teleconference. The committee unanimously recommended a change from a Victoria to a Yamagata lineage strain for next season's vaccine, but expressed concern that data from this season may incomplete. The 2003-2004 vaccine contained a Victoria (B/Hong Kong/330/01-like) strain. Although influenza B outbreaks can occur late in the season, it is unlikely that a significant amount of data will become available before the strain must be selected, the committee agreed. "Relatively few" samples "are in the pipeline," Centers for Disease Control & Prevention Influenza Branch Chief Nancy Cox, PhD, said at a Feb. 19 committee meeting. Anything developed in the next few weeks "would be a limited amount of information." Barring unexpected new data, the committee expects to confirm its existing recommendation on the March 17 call. "It's probably being slightly overcautious" to withhold a full recommendation "because it seems very unlikely that we're going to end up changing our minds, but…caution is a very good thing to do with influenza," committee member David Markovitz, MD, University of Michigan, said. Very little Victoria lineage activity was detected in this season's outbreaks. The 57 influenza B samples isolated by CDC between October and February, included 52 that were of Yamagata lineage. Only .6% of flu specimens tested this season by the World Health Organization and CDC's National Respiratory & Enteric Virus Surveillance System were influenza B viruses. In addition to signals that Yamagata lineage strains are dominant this season, a move away from Victoria lineage strains may provide another advantage. "We've got a population that hasn't seen the Yamagata vaccine for a long time," industry rep and Aventis Pasteur VP-Scientific & Medical Affairs Michael Decker, MD, said. "If we're unsure, we've got to go for the new strain, because if we're wrong, then there's at least the hope of some benefit from prior years' campaigns with the other strain, whereas if we stick with the current strain, we don't have that." The committee recommended a change in one of the two influenza A strains in the current vaccine. The committee recommended retaining the A/New Caledonia/20/99 (H1N1)-like strain and switching to an A/Fujian/411/2002 (H3N2)-like strain from the A/Panama/2007/99-like strain in the current formulation. - Elizabeth Walker |