This is an excerpt from the article, “Flu Activity Picks up Nationwide.” For more information please visit cdc.gov.
So far this season, most (91%) of the influenza viruses that have been analyzed at CDC are like the viruses included in the 2012-2013 influenza vaccine. The match between the vaccine virus and circulating viruses is one factor that impacts how well the vaccine works. But Bresee cautions that other factors are involved.
“While influenza vaccination offers the best protection we have against influenza, it’s still possible that some people may become ill despite being vaccinated,” says Bresee. “Health care providers and the public should remember that influenza antiviral medications are a second line of defense against influenza.” (For more information about why people may become sick with influenza after vaccination, see 2012-2013 season Questions and Answers.)
CDC has recommendations on the use of antiviral medications (sold commercially as “Tamiflu®” and “Relenza®”) to treat influenza illness. Antiviral treatment, started as early as possible after becoming ill, is recommended for any patients with confirmed or suspected influenza who are hospitalized, seriously ill, or ill and at high risk of serious influenza-related complications, including young children, people 65 and older, people with certain underlying medical conditions and pregnant women. Treatment should begin as soon as influenza is suspected, regardless of vaccination status or rapid test results and should not be delayed for confirmatory testing.
To estimate how well influenza vaccines work each year, CDC has been working with researchers at universities and hospitals since the 2003-2004 influenza season conducting studies using laboratory-confirmed influenza as the outcome. Interim VE estimates will be published as soon as they are available. Bresee concludes, “These estimates will provide more information about how well this season’s vaccine is working.”