H3N2 flu 'drift' alarm too late for vaccine
This article was originally published in Scrip
Executive Summary
The head of the Centers for Disease Control and Prevention (CDC) on 4 December acknowledged the agency first detected a "drifting," or mutation, of the influenza A (H3N2) strain as early as March, but said it was too late to make any changes to the current vaccine, which has been determined to be only 48% effective against that strain – now the predominant flu virus circulating in the US.