CDC: Still time to get flu shot as ILI reaches 5.2%

ATLANTA — Based on early data, the Centers for Disease Control and Prevention last week reported that flu vaccines this season are reducing a vaccinated person’s risk of getting sick and having to go to the doctor because of flu by about half (48%). The agency also reported that there are still weeks to go during the current flu season.



CDC recommends that flu vaccination efforts continue as long as influenza viruses are circulating. For the week ended Feb. 11, 5.2% of patient visits reported through the U.S. Outpatient Influenza-like Illness Surveillance Network were due to influenza-like illness. according to CDC. This percentage is above the national baseline of 2.2%.



New York City and 28 states experienced high ILI activity, the CDC reported, while Puerto Rico and seven states experienced moderate ILI activity.



Flu activity — dominated by influenza A H3N2 viruses — has been elevated for 8 weeks this season and continues to increase in some areas. While the Northwest of the country experienced flu activity earlier and now seems to be on the downswing, the Midwest and eastern coast of the country continue to experience increases in activity.



Interim effectiveness estimates against the predominant influenza A (H3N2) viruses are 43% while the interim effectiveness estimate against influenza B viruses is 73%. With weeks to go during the current flu season, vaccination at this time could still offer protective benefit. In the past couple of weeks, a small increase in the proportion of influenza B viruses has been detected. During many seasons, there are later waves of influenza B virus activity.



In the past, significant influenza activity has been observed as late as May. Vaccination efforts should continue as long as influenza viruses are circulating.