Flu Shots Show 40% Effectiveness in Preventing Illness, CDC Reports
As the U.S. winter flu season continues, early estimates from the Centers for Disease Control and Prevention (CDC) suggest that flu shots are performing reasonably well. According to health officials, the vaccines have shown around 40% effectiveness in preventing adults from falling ill enough to require medical attention. Additionally, children who received the vaccine were approximately 60% less likely to seek treatment at a doctor’s office or hospital. While officials generally aim for a flu vaccine to be 40% to 60% effective, the current results indicate a relatively typical flu season.
The effectiveness of flu shots often depends on how well they match the circulating flu strains. Fortunately, this season has seen a good match between the vaccines and the prevalent virus strains. Annual flu vaccines are recommended for everyone aged six months and older in the U.S. However, according to CDC data, only about half of eligible children and adults received flu shots in the past few months.
To track the effectiveness of the vaccines, the CDC utilizes various systems. One such system involves a network of hospitals that provide information on how well the vaccines prevent severe flu-related illnesses requiring admission. Another system collects outpatient data from urgent care clinics and hospital emergency departments. During a recent CDC vaccines meeting, estimates from four different surveillance systems were presented. While the findings were reported as ranges, the midpoints indicated an effectiveness rate of approximately 40% for adults and around 60% for children.
The effectiveness estimate for adults is similar to what was initially reported by the CDC for the previous flu season. However, in some recent seasons, the shots proved to be less effective due to the dominating virus strain and how well the vaccines were matched to it. Dr. Sarah Long of Drexel University expressed disappointment at the recent effectiveness findings, suggesting that there may be diminishing returns for annual influenza immunization. She raised the question of whether repeated vaccinations year after year could be leading to lower immune system responses. While some researchers have explored this question, conclusive results have not yet been obtained.
Despite the varying effectiveness rates, the CDC emphasizes that getting vaccinated is still beneficial. Dr. Lisa Grohskopf of the CDC stated that in general, individuals are better off if they receive the flu vaccine than if they don’t.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. However, the AP is solely responsible for all content.
In conclusion, the current flu season in the U.S. has seen flu shots with an effectiveness rate of around 40% for adults and 60% for children. While these rates fall within the desired range, there is room for improvement. The CDC continues to recommend annual flu vaccines for everyone aged six months and older. Despite concerns about diminishing returns and lower immune system responses, experts emphasize that getting vaccinated is still more beneficial than not. As the winter flu season progresses, it is crucial for individuals to prioritize their health and take necessary precautions to prevent illness.
