Flu vaccine only 23 percent effective this season

the Oncology Nurse Advisor take:

In early January, the Centers for Disease Control and Prevention (CDC) issued a report that supports earlier findings, stating that the efficacy of this year's flu vaccine is low.

A CDC analysis of 2, 321 adults and children with acute respiratory illness found that 41% carried the virus, with 96% having influenza A and the remaining 4% influenza B. Based on this, the CDC estimates that this year's vaccine has reduced an individual's chances of a flu-related doctor visit by 23%.

A reason for the low efficacy could be due to the fact that 70% of this season's H3N2 viruses have been categorized as "drift variants"—viruses that are genetically different from the strains used to make this season's vaccine. 

Approximately 96% of the individuals found in the CDC test to have the flu had influenza A, which are all H3N2 viruses. Vaccine effectiveness against the H3N2 viruses appeared to be greatest amongst the young, with children and teenagers of age 6 months through 17 years showing 26% effectiveness.

Rates of effectiveness were lower for adults 50 years old or older, at 14%, and lower still for the middle demographic of adults of age 18-49, at 12%. H3N2 viruses result in the higher number of hospitalizations and deaths.

Based on this report, the CDC urges all individuals at high risk for flu-related complications to seek out treatment immediately if influenza type symptoms are experienced. The Cdv still recommends that all individuals 6 months of age or older get vaccinated, as the vaccine still protects some people and could also protect against other viruses that may appear at a later date.