The U.S. Centers for Disease Control and Prevention said on Thursday it is too late to make new flu vaccines for the current flu season that could better protect against the predominant flu virus now circulating in the United States. On Wednesday, the CDC sent an advisory to doctors noting that one component of this year's flu vaccine was only partially protective against the predominant flu virus, known as influenza A (H3N2), which has mutated since the current flu shots were made. CDC Director Dr. Thomas Frieden said it takes four months to make a new flu vaccine even using newer cell-based technologies, too long to be helpful in the current flu season.
