Current Flu Vaccine Not Protective Against Two New Strains of Virus
Health officials are concerned that the current flu vaccine is not providing protection against certain strains of the virus that have become prevalent this year, the Sacramento Bee reports.
CDC last week estimated that almost half of the flu cases this season have been caused by two strains of the virus that are not covered by the 2007-2008 vaccine.
The vaccine, developed about a year prior to its intended flu season, is based on the predominant strains of the virus circulating at the time.
David Herbert, an infectious disease specialist at Kaiser Permanente, said recent flu samples in Northern California revealed that 63% matched strains covered by the current vaccine.
Herbert noted, however, that the vaccine can still provide some protection against the flu, even if it does not specifically include newer strains of the virus.
Howard Backer, chief of the immunization branch at the Department of Public Health, said the number of flu cases this year "could definitely get worse before it gets better," although official flu data do not yet suggest an increase in cases compared to past years (Griffith, Sacramento Bee, 2/12).