Protection from Flu Vaccination Reduced this Season
CDC's Morbidity and Mortality Weekly Report reported this season's vaccine offers reduced protection, which underscores the need for additional prevention and treatment efforts this season, including the use of influenza antiviral medications.
A CDC report shows that getting the flu vaccine this season reduced a person's risk of having to go to the doctor because of the flu by 23 percent among people of all ages. Overall estimates for each season have ranged from 10 percent to 60 percent effectiveness since the studies started in 2004-2005.
CDC's Morbidity and Mortality Weekly Report reported this season's vaccine offers reduced protection, which underscores the need for additional prevention and treatment efforts this season, including the use of influenza antiviral medications for treatment.
"Physicians should be aware that all hospitalized patients and all outpatients at high risk for serious complications should be treated as soon as possible with one of three available influenza antiviral medications if influenza is suspected, regardless of a patient's vaccination status and without waiting for confirmatory testing,” says Joe Bresee, branch chief in CDC's Influenza Division. "Health care providers should advise patients at high risk to call promptly if they get symptoms of influenza."
One factor that determines how well a flu vaccine works is the similarity between the flu viruses used in vaccine production and the flu viruses actually circulating. During seasons when vaccine viruses and circulating influenza viruses are well matched, VE between 50 and 60 percent has been observed. H3N2 viruses have been predominant so far this season, but about 70 percent of them have been different or have "drifted" from the H3N2 vaccine virus.