CDC Urges Flu Vaccination Despite Deficient Effectiveness

January 16, 2015
Krystle Vermes

This season's influenza vaccine only reduces a recipient's risk of flu-related medical visits by 23%.

A report published today in the US Centers for Disease Control and Prevention (CDC) Morbidity and Mortality Weekly Report shows that this season’s influenza vaccine only reduces a recipient’s risk of flu-related medical visits by 23%.

Since the CDC started conducting annual influenza vaccine effectiveness studies in 2004-2005, the efficacy rates for preventing such doctor visits associated with seasonal flu have ranged between 10% and 60%. The rate in any given year depends upon the similarity between the circulating influenza virus and the vaccine virus, the CDC said.

In light of the reduced protection offered by this season’s vaccine, the CDC called for additional prevention and treatment efforts, including appropriate use of antiviral medications such as Tamiflu. Although demand is high, there is currently no national shortage of influenza antiviral medications, though the CDC advised pharmacies that are having trouble getting orders filled to contact their distributor or the manufacturer directly. In this week's Pharmacy Times poll, 45% of pharmacists said their pharmacy is currently running low on Tamiflu.

“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,” said Joe Bresee, branch chief in the CDC’s Influenza Division, in a press release. “Health care providers should advise patients at high risk to call promptly if they get symptoms of influenza.”

Despite the weakened effectiveness of the current flu vaccine, the CDC encouraged widespread vaccination because it can still prevent some infections and reduce severe disease that may lead to hospitalization and mortality. So far, flu activity in the 2014-2015 season has been “moderately severe,” with H3N2 viruses predominating.