CDC advises flu shots and caution as ILI rate continues decline
For the second straight week, the rates of influenza-like illnesses as tracked by the Centers for Disease Control and Prevention dropped precipitously. Rates of ILI fell to approximately 5% for the week ended Feb. 24 from a record high two weeks ago.
"While influenza activity continued to decrease in the latest FluView report, it remains high across much of the United States," the CDC reported. "ILI dropped from 6.4% reported last week to 5.0%, and is now similar to ILI observed at the peak of last season. Current data indicate that the 2017-2018 flu season peaked at 7.4% in early February (during weeks 5 and 6) and is now on the decline, however 45 states plus Puerto Rico continue to report widespread flu activity and 32 states plus New York City and the District of Columbia continue to experience high influenza-like illness activity."
CDC continues to recommend influenza vaccination for all persons 6 months of age and older as flu viruses are likely to continue circulating for weeks. While H3N2 viruses remained predominant overall this season, the proportion of B viruses versus A viruses is now almost even. In recent weeks, B viruses have been increasing while H3N2 viruses have been decreasing.
Early vaccine effectiveness estimates show that flu vaccine has reduced the risk of having to go to the doctor due to flu by 36% overall through Feb. 3. Vaccine effectiveness against H3N2 viruses was 25%. However, vaccine effectiveness against H1N1 was 67% and against B viruses was 42%.
In addition, in the context of widespread influenza activity, CDC clinicians and the public are reminded of importance of prompt treatment with influenza antiviral medications in people who are severely ill and people who are at high risk of serious flu complications who develop flu symptoms.