Warning that an earlier-than-usual influenza outbreak could foreshadow a severe flu season, the U.S. Centers for Disease Control and Prevention on Monday urged Americans to be vaccinated to guard against infection.
"We're very concerned that the flu season has had an earlier onset than we've seen in many years, and we are seeing some parts of the country that are having very high levels of widespread flu infection," CDC Director Dr. Julie Gerberding said.
She said influenza was particularly widespread in Texas and that Colorado had also been hard-hit.
Gerberding said the Atlanta-based CDC was concerned about a new strain of flu that does not match the strain in the current vaccine.
But the vaccine will still provide some protection against infection, she said.
"This is the time for Americans to really step up to the plate and get vaccinated against influenza ... especially because we have this particular strain circulating," Gerberding said.
The shot is recommended for adults older than 50, children between 6 months and 2 years old, people with chronic medical conditions and people who work in health care.
The strain of flu showing up this year is part of a group called H3N2, which leads to more deaths and hospitalizations than other flu strains.
But because this year's vaccine targets a slightly different type of H3N2 flu than patients are getting, doctors don't know how well the shots will work.