Stephanie Dugger, 20, gets a flu shot from nurse Bhagwati Bhakta at Mollen Immunization Clinics in Scottsdale, Ariz.(Photo: Cheryl Evans, The Arizona Republic)
The flu was widespread in 47 states as of the first week of January
and this flu season has so far killed a total 21 children, the Centers
for Disease Control and Prevention said Friday.
This year's flu
vaccine appears to be about 62% effective against the currently
circulating strains, according to CDC. This is "moderate effectiveness"
according to CDC's report and slightly above the usual level of
effectiveness for flu vaccine based on previous research.
A WEEKLY LOOK AT INFLUENZA ACROSS THE USA
the vaccine is not 100% effective, vaccination is still crucial for not
only personal but also public health. It offers substantial protection
for the individual. In addition, people who have been vaccinated and
later go on to get the flu appear to have much milder cases. And those
same people also shed less flu virus, making it less likely they'll pass
it along to those around them, said Arnold Monto, a professor of
epidemiology at the University of Michigan in Ann Arbor, Mich., and a
member of the Infectious Diseases Society of America's Influenza
Advisory Group, which works with CDC.
year about 35% of the U.S. population is on track to be vaccinated,
said CDC spokesman Tom Skinner. "Certainly it is not perfect but it's a
better defense versus not having flu vaccine."
Anecdotal reports from some medical centers show some people who had documented flu shots later coming down with the flu.
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Glatter, an emergency medicine physician at Lenox Hill Hospital in New
York, is seeing indications that this year's vaccine may not be as
protective as had been hoped, especially against Influenza B, one of
three flu strains currently circulating. "This may be contributing to
some patients' profound and severe symptoms associated with the 2013
outbreak" he said.
Michael Osterholm, director of the Center for
Infectious Disease Research and Policy, says a careful analysis of the
data shows that the flu vaccine's "match" has little to do with its
effectiveness. Even flu vaccines that are well-matched for the flu
strains in circulation may still offer poor protection, says Osterholm,
also a professor at the University of Minnesota School of Public
A report released four months ago by the the Center for
Infectious Disease Research and Policy at the University of Minnesota
found that while many studies put the efficacy of flu vaccine for
healthy adults at between 70% to 90%, when they only looked at
well-designed and rigorous studies it was closer to 59% for healthy
adults between 18 and 64 years of age. The intranasal vaccine, sold as
FluMist, is about 83% effective for children ages 6 months to 7 years,
the report says.
The flu vaccine used in the United States is
based on the mix of flu viruses circulating in the Southern Hemisphere
the season before. Every year virologists at the World Health
Organization look at the mix and attempt to predict what will appear in
the Western hemisphere later in the year.